Special Purpose Fans and Blowers | Rotating Equipment Engineering

 

1 Scope 2 References
2.1 SABIC Engineering Standards (SES) 2.2 Air Movement and Control Association (AMCA) 2.3 American Petroleum Institute (API) 2.4 American Society for Testing and Materials (ASTM) 2.5 American Society of Mechanical Engineers (ASME) 2.6 American Welding Society (AWS) 2.7 Anti-Friction Bearing Manufacturers Association (ABMA)2.8 National Fire Protection Association (NFPA) 2.9 Structural Steel Painting Council (SSPC)
3 Definitions 4 Design
4.1 General 4.2 Fan Housing 4.3 Fan Housing Connections 4.4 External Forces and Moments 4.5 Rotating Elements 4.6 Shaft Sealing of Fans 4.7 Critical Speeds / Resonance 4.8 Vibration and Balancing 4.9 Bearings and Bearing Housings 4.10 Lubrication
5 Materials 5.1 General 5.2 Castings 5.3 Welding 5.4 Low Temperature
6 Nameplates 7 Accessories

7.1 Drivers 7.1.1 General 7.1.2 Motors 7.1.3 Turbines 7.1.4 Gears
7.2 Couplings and Guards 7.3 Clutches 7.4 Mounting Plates
7.4.1 General 7.4.2 Baseplates 7.4.3 Driver Shim Packs 7.4.4 Leveling Screws
7.5 Controls and Instrumentation 7.5.1 General 7.5.2 Control Systems 7.5.3 Dampers and Inlet Guide Vanes 7.5.4 Bearing Housing Vibration Detection 7.5.5 Shaft Vibration Detection 7.5.6 Sleeve Bearing Temperature Detection
7.6 Piping and Appurtenances 7.7 Inlet Systems 7.8 Silencers 7.9 Coatings, Insulation and Jacketing
7.9.1 Coatings 7.9.2 Insulation and Jacketing
7.10 Turning Gear 8 Inspection and Testing
8.1 General 8.2 Inspection
8.2.1 General 8.2.2 Material Inspection
8.3 Shop Assembly

8.4 Testing 8.4.1 General 8.4.2 Hydrostatic Test 8.4.3 Optional Tests
9 Preparation for Shipment 10 Vendor Data

10.1 Proposals 10.1 Contract Data
10.1.1 Drawings 10.1.2 Performance Curves 10.1.3 Data 10.1.4 Vendor Information

Table 1: Shaft Mechanical Run-out

1 Scope
1.1 This specification is for special purpose centrifugal fans and blowers. It is primarily intended for
fans and blowers that are in continuous duty on process units, heaters and boilers, and which
are generally un-spared.
1.2 Cooling tower fans, ventilation fans and positive displacement blowers are not covered by this
specification.
1.3 General purpose fans and blowers are covered in SES G11-S01.
2 References
Reference is made in this specification to the following documents. The latest issues, amendments,
and supplements to these documents shall apply unless otherwise indicated.
2.1 SABIC Engineering Standards (SES)
2.1.1. E02-E02: Hazardous Area Classification
2.1.2. E06-S01: Induction Motors 150 kW and Below
2.1.3. E06-S02: Induction Motors 185 kW and Above
2.1.4. G03-S01: Lubrication, Shaft Sealing, Control Oil Systems and Auxiliaries
2.1.5. G06-S01: General Purpose Steam Turbines
2.1.6. G06-S02: Special Purpose Steam Turbines
2.1.7. G07-S01: General Purpose Gears
2.1.8. G07-S02: Special Purpose Gears
2.1.9. G11-S01: General Purpose Fans and Blowers
2.1.10. G12-S01: Special Purpose Couplings
2.1.11. S20-G01: Plant Equipment Noise Limits
2.1.12. X01-S03: Instrumentation for Packaged Equipment
2.2 Air Movement and Control Association (AMCA)
2.2.1. AMCA 201 Rev.02: Fans and Systems
2.2.2. AMCA 203 Rev.90: Field Performance Measurement of Fan Systems
2.2.3. AMCA 210 Rev.07: Laboratory Methods of Testing Fans for Aerodynamic Performance
Rating
2.2.4. AMCA 99-2404 Rev.03: Drive Arrangements for Centrifugal Fans

2.3 American Petroleum Institute (API)
2.3.1. API RP 500 Rev.97: Classification of Locations for Electrical Installation at Petroleum
Facilities Classified as Class 1, Division 1 and Division 2
2.3.2. API 617 Rev.7: Axial and Centrifugal Compressors and Expander-compressors for
Petroleum, Chemical and Gas Industry Services
2.3.3. API RP 686 Rev.1: Recommended Practices for Machinery Installation and Installation
Design
2.4 American Society for Testing and Materials (ASTM)
2.4.1. A 278/A 278M Rev.01: Standard Specification for Gray Iron Castings for PressureContaining
Parts
for
Temperatures
Up
to
650
Degrees
F
(350
Degrees
C)

2.4.2. A 395M Rev.99: Ferritic Ductile Iron Pressure-Retaining Castings for Use at Elevated
Temperatures (Metric)
2.4.3. A 515/A 515M Rev.03: Standard Specification for Pressure Vessel Plates, Carbon Steel,
for Intermediate- and Higher-Temperature Service
2.4.4. E 94 Rev.04: Standard Guide for Radiographic Examination
2.4.5. E 709 Rev.08: Standard Guide for Magnetic Particle Testing
2.5 American Society of Mechanical Engineers (ASME)
2.5.1. B1.20.1 Rev.83: Pipe Threads, General Purpose (Inch)
2.5.2. B16.5 Rev.03: Pipe Flanges and Flanged Fittings NPS ½ Through NPS 24 Metric/Inch
Standard
2.5.3. PTC 11 Rev.84: Fans
2.5.4. BPVC Section V Rev.07: Nondestructive Examination
2.5.5. BPVC Section VIII Rev.07: Pressure Vessels
2.5.6. BPVC Section IX Rev.07: Welding and Brazing Qualifications
2.6 American Welding Society (AWS)
2.6.1. D1.1 Rev.08: Structural Welding Code – Steel
2.6.2. D14.6/D14.6M: Rev.05: Specification for Welding of Rotating Elements of Equipment
2.7 Anti-Friction Bearing Manufacturers Association (ABMA)
2.7.1. ABMA STD 9 Rev.07: Load Ratings and Fatigue Life for Ball Bearings
2.8 National Fire Protection Association (NFPA)
2.8.1. NFPA 70 Rev.08: National Electrical Code (NEC)

2.9 Structural Steel Painting Council (SSPC)

2.9.1. SP 10 Rev.07: Near-White Metal Blast Cleaning
3 Definitions
For the purpose of understanding this specification, the following definitions apply:

DN Number. The product of bearing size (bore) in millimeters and the rated speed in revolutions per
minute.
Evase. A diffuser or a diverging discharge transition piece.
Fan Impeller. The assembly of the fan wheel and the hub(s).
Fan Rated Point. (1) The highest speed necessary to meet any specified operating condition and (2)
the rated capacity required by fan designs to meet all operating points. Vendor shall select this
capacity point to best encompass specified operating conditions within the scope of the expected
performance curve.
Fan Wheel. The assembly comprised of the blades, centerplate (or backplate), shroud(s) and wear
plates if used.
Hydrodynamic Bearings. Bearings that use the principles of hydrodynamic lubrication. Their
surfaces are oriented so that relative motion forms an oil wedge to support the load without journal to
bearing contact.
L
Life. The number of hours at rated bearing load and speed that 90 percent of the group of
identical bearings will complete or exceed before the first evidence of failure.
10
Maximum Allowable Temperature. The maximum continuous temperature for which the
manufacturer has designed the equipment (or any part to which the term is referred) when handling
the specific fluid at the specified temperature.
Maximum Allowable Working Pressure (MAWP). The maximum continuous pressure for which the
manufacturer has designed the equipment (or any part to which the term is referred) when handling
the specific fluid at the specified temperature.
Maximum Continuous Speed. The speed in revolutions per minute, at least equal to 105 percent of
the highest speed required by any of the specified operating points.
Normal Operating Point. The point at which usual operation is expected and optimum efficiency is
desired. Fan performance shall be guaranteed at the normal operating point unless otherwise
specified.
Shaft Cooler or Heat Slinger. A fan (impeller) mounted on the shaft between the seal(s) and
bearings that reduces transfer of heat from the case to the bearings.
Sound Trunk. The silencer(s) plus transition piece(s) between silencer(s) and fan.
Trip Speed. Trip speed in revolutions per minute, for steam turbine drives shall be approximately 110
percent of the maximum continuous speed.

Unit Responsibility. The responsibility for coordinating the technical aspects of the equipment and
all auxiliary systems included in the scope of the order.
4 Design
In this specification the term fan and blower may be used interchangeably.
4.1 General

4.1.1. The equipment, including auxiliaries, covered by this specification shall be suitable for the
specified operating conditions and shall be designed and constructed for a minimum
service life of 20 years and at least 3 years of uninterrupted continuous service. It is
recognized that this is a design criterion and that periodic monitoring will have to be
performed to ensure uninterrupted service.
4.1.2. Vendor shall assume unit responsibility for all equipment and all auxiliary systems included
in the scope of the order.
4.1.3. Fans shall be supplied by vendors qualified by experience in manufacturing the unit
proposed. To qualify, the vendor shall have manufactured, at the point of manufacture, at
least two units of comparable power, speed, and service which have been operating
satisfactorily for more than 3 years at similar conditions.
4.1.4. Where the vendor qualification above prevents the application of the latest technology,
vendor may submit a second or alternative proposal, specifically identifying the features
undemonstrated by experience, and state their advantages.
4.1.5. Fans shall be designed and constructed to operate satisfactorily at all specified operating
conditions, maximum continuous speed, and to the trip setting of the driver, if applicable.
Vendor shall advise or SABIC shall specify the minimum operating conditions, for example
flow and speed. The two operating points of particular concern are the rated point and the
normal operating point.
4.1.6. Unless otherwise specified, fans shall be installed outdoors without a roof in Saudi Arabia.
Weather conditions in which the equipment shall operate, including maximum and
minimum temperatures, unusual humidity, and dust problems shall be shown on the data
sheets. The unit and its auxiliaries shall be suitable for operation in the specified
conditions. Vendor shall list in the proposal any special protection required.
4.1.7. Fan arrangement and bearing support, whether double-width/double-inlet or singlewidth/single-inlet,
shall
be
AMCA
2404,
Arrangement
3
or
7,
with
the
fan
wheel
located

between
bearings,
the
bearings
mounted
on
independently
supported
pedestals,
and
the

bearings
protected
from
the
air
or
gas
stream
by
means
of
inlet
boxes
when
any
of
the

following
conditions
exist:

a. Induced draft service
b. Impeller diameter greater than 1500 mm for a forced draft fan
c. Speed greater than 1800 rpm
d. Driver rated power of 110 kW (150 HP) or greater

e. Design temperature of 220 °C (428 °F) or greater
f. Toxic, flammable or other hazardous service
g. Corrosive or erosive service
h. Service subject to fouling deposits that could cause rotor unbalance
4.1.8. For services not subject to the conditions in ‎4.1.7, AMCA 2404 arrangements 1 or 8, with
bearings mounted independent of the fan housing, shall be acceptable subject to SABIC
approval.
4.1.9. The arrangement of the equipment, including ducting and the auxiliaries, shall be
developed jointly by SABIC and vendor. The arrangement shall provide adequate
clearance areas and safe access for operation and maintenance
4.1.10. Fan performance shall be based on the static pressure differential across the fan inlet and
outlet flanges. To obtain this differential, silencer and inlet losses, including control system
losses, shall be added by vendor to SABIC‟s specified inlet and outlet losses.
4.1.11. Performance curves shall have a continuous rising pressure characteristic from the rated
point, as specified, to at least 60 percent of rated flow. For parallel operation, fan
performance curves shall have a continuously rising pressure characteristic from the rated
capacity to surge. Performance curves, corrected for the specified gas at the specified
conditions, shall be based on performance tests in accordance with AMCA 210, including,
where applicable, evase and inlet box(es).
4.1.12. The rated speed of the fan shall not exceed 1800 rpm unless specifically approved by
SABIC.
4.1.13. Fan shall be of a „stiff shaft‟ design complying with 4.7.1.
4.1.14. Induced draft fans shall be mechanically designed for operation at least 50 °C above
maximum specified inlet gas temperature. Forced draft fans shall be mechanically
designed for operation at least 25 °C above maximum specified ambient air temperature.
4.1.15. Fan, components and accessories shall be designed to withstand all loads and stresses
during rapid load changes, for example direct-on-line (D.O.L.) starting of motor drivers,
failure of damper actuator and sudden opening of dampers.
4.1.16. Electric motors, electrical components and electrical installations shall be suitable for the
area classification and groupings specified on the data sheets, and shall meet the
requirements of API RP 500, NFPA 70 and SES E02-E02.
4.1.17. Unless otherwise specified, the equipment furnished by vendor shall not exceed a noise
level of 85 dBA measured at 1 m when operated at the specified conditions. Vendor shall
furnish silencers, sound trunks, and/or the acoustical treatment necessary to reach the
specified noise level on the intake of forced draft fans. Vendor shall provide in his
proposal details of the acoustical treatment required to reach this noise level for the
radiated noise from the inlet boxes and housing. The complete installation shall conform
to the requirements of SES S20-C01.
4.1.18. Oil reservoirs and housings which enclose moving lubricated parts, for example bearings,
shaft seals, highly polished parts, instruments, and control elements, shall be designed to
minimize contamination by moisture, dust, and other foreign matter during periods of
operation and idleness.
4.1.19. All equipment shall be designed to permit rapid and economical maintenance. Major
parts, for example, fan housing, inlet cone, and bearing housings, shall be designed and
manufactured with features (e.g. shoulders or dowels) to ensure accurate alignment on
reassembly. Shaft seals and bearings shall be accessible for inspection and replacement
with minimum disassembly of the fan or duct work.
4.1.20. When tools and fixtures, not commercially available, are required to disassemble,
assemble or maintain the units, they shall be included in the proposal and furnished as
part of the initial supply of the fan. For multi-unit installations, the requirements for
quantities of special tools and fixtures shall be mutually agreed upon by SABIC and
vendor.
4.1.21. Vendor shall formally review and approve or comment on SABIC‟s inlet and outlet duct
and equipment arrangement drawings. This review shall consider structural aspects, for
example loading on fan parts, and configuration details that impact fan performance as
described in AMCA 201. Foundation drawing review shall not be required unless specified
by SABIC.
4.1.22. Spare parts for the machine and all furnished auxiliaries shall meet all the criteria of this
specification.
4.2 Fan Housing
4.2.1. The fan housing shall be continuously welded plate construction with scroll housing. Adequate
stiffeners shall be provided to form a rigid housing free of structural resonance and to limit
vibration and noise. Minimum plate thickness shall be 6 mm.
4.2.2. For AMCA 2404 arrangement 3 and 7 fans, the housing and inlet boxes shall be split at a bolted,
flanged and gasketed connection, for assembled rotor removal or access without disturbing
duct connections. Other arrangements shall be similarly split where impeller diameter exceeds
1060 mm.
4.2.3. The inlet cone shall be constructed in a way that is does not impede rotor removal or installation.
The cone shall be split, separately removable as a whole, or removable in assembly with the
rotor.
4.2.4. Bolted and gasketed access doors, minimum 600 x 600 mm, shall be provided in the scroll and
inlet box(es) for access to the fan internals for inspection, cleaning, rotor balancing and any
internal bolting necessary for rotor removal. If fan size and construction shall not permit 600 x
600 mm access doors, the largest possible access openings shall be provided in the scroll and
inlet box(es).
4.2.5. Adequate flanged sections shall be provided in the fan housing and inlet box(es) to allow rotor
removal without requiring personnel entry into the inlet box(es).
4.2.6. Induced draft fan housing shall have side and full width scroll liners of abrasion resistant
material. The material shall be retained in place as agreed upon by vendor and SABIC. As an
option, double thick side walls and scrolls may be supplied.

4.2.7. The direction of rotation of the fan shall be clearly and permanently marked on the housing.
4.3 Fan Housing Connections

4.3.1. Inlet and discharge connections shall be flanged and bolted. Facings of all connections
shall be adequate to prevent leakage with proper gaskets and bolting.
4.3.2. Accessible flanged drain connections, 2 inch minimum size, shall be provided at the low
points of the housing and inlet boxes.
4.4 External Forces and Moments
Vendor shall design the housing to accept the specified loads. Vendor shall provide the following
information as required on the data sheets:
4.4.1 Maximum allowable forces and moments
4.4.2 Expansion joint information and recommendations if joints are required for thermal expansion or
vibration isolation

4.5 Rotating Elements
4.5.1 Materials selection shall be by joint agreement between SABIC and vendor. Vendor shall fully
detail materials, thickness and construction details for each rotor assembly.
4.5.2 Fan impellers shall have a non-overloading power characteristic and shall be designed for the
highest possible efficiency. Forced draft fans may be a backward inclined blade or backward
curve air foil type. Induced draft fans may be backward inclined blade or backward curved air
foil type for clean gas service. Radial or radial tipped blade types shall be used for fans in dirty
gas service.
4.5.3 Welded construction of the fan wheel shall be required. Shrouds, back plates and center plates
should usually be of one piece construction, but may be fabricated if the sections are joined by
fully inspected full penetration butt welds. Welded layers or laminations of plate to increase
thickness of highly stressed areas shall not be permitted, excepting wear plates for abrasion or
erosion. Corrosiveness, erosiveness and temperature of the gas shall be considered during
material selection. Vendor shall state whether post weld heat treatment of the fabricated wheel
is required after consideration of environmental and mechanical (residual stress) effects.
4.5.4 On induced draft fans, corrosion resistant shaft sleeves shall be provided to reduce the effect of
dew point corrosion at shaft seals. Sleeves shall extend 150 mm into the fan housing or to the
impeller hub. A shaft sleeve shall be installed with an interference fit, and the assembly shall
take into account differential thermal expansion at the highest operating temperature. After
assembly of the shaft, mechanical run-out on the shaft sleeve in the seal area shall not exceed
25 µm total indicated run-out, or 50 µm total indicated run-out over the entire sleeve length.
4.5.5 Impellers shall have solid hubs, be keyed to the shaft and be secured with an interference fit.
Cast or ductile iron hubs shall only be acceptable below a mechanical design temperature of
150 °C or a fan tip speed of less than 100 m/s. When the impeller is to be bolted to the hub,
vendor shall by design, preclude relative movement between the impeller and hub.

4.5.6 Gas temperature change rates, heating and cooling in excess of 8 °C/min may be expected on
induced draft fans. Vendors shall specify the maximum allowable rate of change to ensure that
an adequate hub to shaft interference fit is maintained.
4.5.7 Shafts shall be of one piece, heat treated, forged steel. Shafts 150 mm in diameter and smaller
may be machined from hot rolled bar stock. Shaft diameter shall be stepped on both sides of
the impeller fit area to facilitate impeller removal on AMCA 2404 arrangements 3 or 7. Fillets
shall be provided at all changes in shaft diameters and in keyways. Welding on the shaft shall
not be permitted.
4.5.8 Shafts shall be capable of handling 110 percent of the rated driver torque from rest to rated
speed.
4.6 Shaft Sealing of Fans
4.6.1. Shaft seals shall be provided to minimize leakage from or into fans over the range of specified
operating conditions and during idle periods. Seal operation shall be suitable for variations in inlet
conditions that may prevail during startup and shutdown or any special operation specified by
SABIC.
4.6.2. Fans with negative pressure at the inlet box(es), except forced draft fans in air service, and
induced draft fans exhausting to atmosphere, shall be provided with double seals suitable for
pressurization if specified.
4.6.3. When the seal is specified to be in toxic, high pressure, or flammable service, provision for a
centralized buffer gas injection or eductor system, or both, shall be supplied, to minimize leakage.
System details shall be mutually agreed upon by SABIC and vendor.
4.6.4. Shaft seals shall be replaceable from the outside of the inlet box(es) without disturbing the shaft
or bearings.
4.6.5. Shaft seal clearances and materials shall be based on the operating temperature as specified by
SABIC. Temperature excursions shall also be considered in the design.
4.7 Critical Speeds / Resonance
4.7.1. Unless otherwise specified, the separation margin of critical speeds from all lateral
(including rigid and bending) modes shall be at least 25 percent above the maximum
continuous speed. This margin is intended to prevent the overlapping of the resonance
envelope into the operating speed range.
4.7.2. There shall be no resonances of the support systems within the vendor‟s scope of supply,
within the specified operating speed range including 25% separation margins on both sides
thereof, unless the resonance is critically damped.
4.7.3. Bearing housing resonance shall not occur with the specified operating speed range or
specified separation margins.
4.7.4. When specified, critical speeds shall be determined analytically by means of a damped
unbalanced rotor response analysis and, when specified, shall be confirmed by test stand data.
4.7.5. The vendor shall determine that the drive train critical speeds are compatible with the
critical speed of the machinery being supplied and that the combination is suitable for the

specified operating speed range. A list of all undesirable speeds from zero to trip shall be
submitted to SABIC for review and included in the instruction manual for later operational
guidance.
4.7.6. The vendor shall perform a torsional vibration analysis of the complete fan/driver unit for
the following cases:
a. Direct coupled electric motor or an electric motor and gearbox rated 750 kW and larger.
b. Variable speed electric motor rated 1000 kW and higher.
c. Steam turbine driver rated 1500 kW and higher.
4.7.7. The vendor shall be responsible for the unit‟s satisfactory performance. Torsional modes
of the complete fan driver unit shall be at least 10 percent removed from any operating speed
to trip speed, or two times any operating speed to trip speed. For a motor drive, the maximum
continuous speed shall be considered the trip speed.
4.7.8. A similar analysis and assumption of responsibility shall be required for any engine driven
or synchronous motor driven fan. Vendor shall submit to SABIC the calculation procedure and
summary of shaft stresses if a torsional critical speed occurs within 20 percent of any operating
speed.
4.7.9. Vendor shall perform a transient torsional vibration analysis for synchronous motor driven
and engine driven units and shall be responsible for the unit‟s satisfactory performance.
4.8 Vibration and Balancing
4.8.1 Major parts of the rotating element, for example the shaft, balancing drum and impellers shall be
dynamically balanced. When a bare shaft with a single keyway is dynamically balanced, the
keyway shall be filled with a fully crowned half key. The initial balance correction to the bare
shaft shall be recorded. A shaft with two keyways 180° apart but not in the same transverse
plane shall also be filled as described above.
4.8.2 The rotating element shall be multi-plane dynamically balanced during assembly. This shall be
accomplished after the addition of no more than two major components. Balancing correction
shall only be applied to the elements added. Minor correction of other components may be
required during the final trim balancing of the completely assembled element. On rotors with
single keyways, the keyway shall be filled with a fully crowned half key. The mass of all half
keys used during the final balancing of the assembled element shall be recorded on the
residual unbalance work sheet.
The phase reference mark shall preferably coincide with the keyway or other defined unique
angular position on the rotor.
The maximum allowable residual unbalance per bearing plane shall be calculated as follows:

Umax = 6350W/N

Where:

Umax = Residual unbalance [g.mm]
W = Journal static mass loading [kg]
N = Maximum continuous speed [r/min]

Where spare rotors are supplied, they shall be dynamically balanced to the same tolerance as
the main rotor.
4.8.3 After the final balancing of each assembled rotating element has been completed a residual
unbalance check shall be performed and recorded before the rotor is removed from the
balancing machine. The procedure for determining residual unbalance shall conform to
API 617, Annex 1B.
4.8.4 Prior to rotor assembly the shaft shall be inspected for mechanical run-out and concentricity at
impeller mounting surface seat and bearing journals. The shaft shall be supported at its
bearing surfaces in V-blocks for these measurements. Run-out shall not exceed the Total
Indicated Run-out shown in Table 1:

Table 1: Shaft Mechanical Run-out

 

4.8.5 A run-out recheck shall be made of the impeller outside diameter after rotor assembly and prior
to balancing.
4.8.6 Balance weights, if required, shall not exceed 6 mm in thickness, and shall not exceed the
thickness of the member to which the weight is attached. They shall be continuously welded
onto the wheel in two or three defined balancing planes.
4.8.7 To minimize flow separation, balance weights required in the gas passage shall be blended to
the impeller surfaces producing a fillet angle of not less than 160°.
4.8.8 During shop testing and when installed on its permanent location, the maximum peak vibration
velocity measured on the bearing housing of the assembled fan, operating at maximum
continuous speed or at any other speed within the specified operating speed range, shall not
exceed:

a. 5 mm/s peak unfiltered in any plane (rigid support)
b. 2.5 mm/s peak at any discrete frequency (filtered) in any plane
c. Vibration at two times running frequency (2X) in any plane shall be less than 50% of the
vibration at running frequency (1X)
Note: If vibration isolators are employed, it shall be blocked during this test.
4.8.9 At the trip speed of the driver, the vibration shall not exceed 6.0 mm/s peak unfiltered in any
plane.
4.8.10 For rotors with hydrodynamic bearings, the acceptance limit for peak to peak shaft
displacement, in any plane adjacent to the bearing housing, is 50 µm. This value includes any
proven mechanical and electrical run-out.
4.9 Bearings and Bearing Housings
4.9.1. Bearing types shall be either anti-friction or hydrodynamic (sleeve). Unless otherwise specified,
fans with shaft diameters larger than 100 mm nominal shall have horizontally split, Babbitt lined,
ring-oiled, self-aligning hydrodynamic bearings with oil gage and inspection cap. Bearings shall
be of readily available types and sizes.
4.9.2. Anti-friction bearings shall be self aligning and the selection shall be based on the following
ratings:
a. DN number (shaft diameter x speed) less than 200 000 [mm.r/min]
b. Calculated L
Life (see ABMA 9) of 100 000 hours minimum
c. The use of „maximum load‟ (filling slot) anti-friction bearings shall be prohibited
d. Ball type thrust bearings shall be one pair angular contact bearings (7000 series),
10
installed back to back with 40° load angle and light preload
4.9.3. Thrust bearings shall be sized for continuous operation under all specified conditions, including
double inlet fans operating with one inlet cone 100 percent blocked. As a guide, thrust bearings
shall be applied at no more than 50 % of the bearing manufacturer‟s ultimate load rating.
4.9.4. Thrust collars for hydrodynamic bearings shall be located in the inboard (coupling end) bearing.
Thrust collars shall be integral or installed with substantial shrink fit to prevent fretting, and shall
be positively locked to prevent axial movement. Integral collars shall be provided with a
minimum of 3 mm additional stock on each thrust face for re-machining should the collar be
damaged. Thrust faces shall be machined after collar installation, if necessary, to provide a
maximum of 13 µm total indicated face run-out. Split thrust collars shall not be acceptable.
4.9.5. Bearing housings for hydrodynamic bearings designed for pressure lubrication shall be arranged
to minimize foaming. The drain system shall be adequate to maintain the oil and foam level
below shaft ends. Oil temperature rise through the bearing housing shall not exceed 28 °C
under the most adverse specified operating conditions when inlet oil temperature is 43 °C.
Where oil temperatures exceed 43 °C, special consideration shall be given to bearing design, oil
flows and allowable temperature rise. Oil outlets from thrust bearings shall be tangential in the
oil control ring or in the thrust bearing cartridge if oil control rings are not used.

4.9.6. Bearing housing for oil lubricated non-pressure fed bearings shall be provided with
1/2 inch
valved connections with caps. They shall be equipped with 0.5 L minimum size constant level
sight feed oilers supported independently of the oil piping (such that they will not rotate/turn
during operation), with translucent containers not subject to sunlight or heat induced opacity,
and with protective wire cages. These oilers shall meet SABIC‟s preference when specified. A
permanent indication of proper oil level shall be accurately located and clearly marked on the
outside of the bearing housings with permanent metal tags, marks inscribed in the castings, or
other durable means.
4.9.7. Bearing housings shall be equipped with labyrinth, double contact type end seals or “Inpro/Seal”
seals where the shaft passes through the housing. Lip type seals shall not be used. The shaft
seal design shall effectively retain oil in the housing and prevent entry of foreign material into
the housing. Provision shall be made for NPS ¼ pipe air purge of the labyrinth seal.
4.9.8. Bearing housings having a shaft diameter of 50 mm or larger shall have a 28 mm diameter spot
face on the side of the bearing housing just below the horizontal split-line for horizontal
positioning of an accelerometer.
4.9.9. Where water cooling is required, water jackets shall have only external connections between the
upper and lower housing jackets and shall have no gasketed or threaded connection joints
which may cause water leakage into the oil reservoir. Cooling coils (including fittings), if used,
shall be nonferrous material and shall have no pressure joints or fittings inside the bearing
housing. Coils shall be at least 1.07 mm minimum thickness and shall be at least 12.7 mm in
diameter.
4.9.10. When air cooling is approved or specified, shaft mounted fans shall be provided to prevent
excessive heat transmission from the shaft and fan housing to the bearings. All induced draft
fans shall be supplied with shaft coolers (heat slingers) located between the fan housing and
bearing housing. The design of the heat removal fans and the shaft mounting arrangement
shall be described in vendor‟s proposal.
4.9.11. Shaft bearings shall be accessible without dismantling duct work or the fan casing.
Overhung impeller designs shall have provisions for supporting the rotor during bearing
maintenance.
4.9.12. Bearing housings shall be drilled with pilot holes for use in final doweling.
4.10 Lubrication
4.10.1. Unless otherwise specified, bearing and bearing housings shall be arranged for
hydrocarbon oil lubrication in accordance with the bearing manufacturer‟s
recommendations. Grease packed anti-friction bearings shall not be provided without
SABIC‟s approval.
4.10.2. All linkages, shaft fittings and bearings on dampers and variable inlet vanes shall be
permanently lubricated. Components requiring periodic lubrication shall be furnished with
lubrication fittings which are accessible while the fan is in operation.
4.10.3. When a pressurized or circulating lubrication system is required by a gear or driver, the fan
bearing oil may be supplied from that system. SABIC shall specify the supplier of the

 

complete lubrication system. When specified, the system shall be in accordance with SES
G03-S01.
5 Materials
5.1 General
5.1.1. Materials of construction shall be the manufacturer‟s standard for the specified operating
conditions, except as required in SES G11-X02 or this specification. The corrosion
allowance for carbon steel plate shall be 3 mm.
5.1.2. Materials shall be identified in the proposal with applicable ASTM or ISO numbers, and
material grade. If other material specifications are used, then its equivalent grades in
ASTM or ISO shall be given as well as its chemical composition, heat treatment and
mechanical properties.
5.1.3. Damper and variable guide vane actuating mechanisms, linkages and other external parts
subject to rotary or sliding motions shall be of corrosion resistant materials suitable for the
site environment. Internal operating parts, subject to rotary or sliding motions, shall be
stainless steel or other equally corrosion resistant material. Minor parts associated with
such mechanisms, for example bolts, nuts, springs, washers, gaskets and keys shall have
equal corrosion resistance.
5.1.4. SABIC shall specify any corrosive agents present in the motive and process fluids and in
the environment, including constituents which may cause stress corrosion cracking.
5.1.5. Low carbon or stabilized grades of austenitic stainless steel shall be used when parts
made of these materials shall be fabricated, hard surfaced, overlaid or repaired by
welding, and shall be exposed to a motive fluid, to a process fluid, or to an environmental
condition which induces inter-granular corrosion.
5.1.6. Low carbon steels can be notch sensitive and susceptible to brittle fracture at ambient or
low temperatures. Only fully killed, normalized steels made to fine grain practice shall be
acceptable. The use of ASTM A 515 steel shall be prohibited.
5.1.7. Where mating parts, for example studs and nuts of type 300 stainless steel or materials
with similar galling tendencies are used, they shall be lubricated with an anti-seizure
compound rated for the specified temperatures.
5.1.8. Materials having a yield strength in excess of 620 MPa, or a hardness in excess of
22 Rockwell C (22 HRC), shall not be used for components exposed to wet H2
S service,
including trace quantities. Components which are fabricated by welding shall be stress
relieved, if required, to ensure that both the welds and the heat affected zones meet the
yield strength and hardness requirements.
5.2 Castings
5.2.1. Castings shall be sound and free of shrink holes, blow holes, cracks, scale, blisters or
other similar injurious defects. Surfaces of castings shall be cleaned by sandblasting,
shotblasting, pickling or any other standard method. All mold parting fins and remains of
gates and risers shall be chipped, filed or ground flush.
5.2.2. Ferrous castings shall not be repaired by welding, peening, plugging, burning-in or
impregnating, except as follows:
a. Weldable grades of steel castings may be repaired by welding, using a qualified welding
procedure conforming to ASME Section IX
b. Cast grey iron or nodular iron may be repaired by plugging, in accordance with ASTM A 395M.
The drilled holes for a plug shall be carefully examined by dye penetrant to ensure the removal
of all defective material. All necessary repairs not covered by ASTM shall be subject to SABIC
approval.
5.2.3. Fully enclosed cored voids, including voids closed by plugging, shall be prohibited.
5.3 Welding
5.3.1. All welding, and weld repairs, shall be performed by operators and procedures qualified in
accordance with AWS D14.6 for rotor welds, and AWS D1.1 for housings and inlet boxes.
5.3.2. Vendor shall review all welding and weld repair, to ensure that the requirements of AWS
D14.6, Section 7, have been satisfied.
5.3.3. All rotor component butt welds shall be continuous, full penetration welds.
5.3.4. Intermittent welds, stitch welds or tack welds shall not be permitted on any part of the fan
or accessories furnished by vendor. Such welds used for parts positioning during
assembly shall be removed.
5.4 Low Temperature
For operating temperatures below -29°C, or when specified for other low ambient temperatures, steels
shall have, at the lowest specified temperature, an impact strength sufficient to qualify under the
minimum Charpy V-notch impact energy requirement of ASME Section VIII, Div 1, UG-84.
6 Nameplates
6.1. A nameplate shall be securely attached at an easily accessible point on the equipment and
on any other major piece of auxiliary equipment.
6.2. The rated conditions and other data shall be clearly stamped on the nameplate and shall
include the following:
a. Vendor
b. Model Number
c. Size
d. Type
e. SABIC equipment number
f. Volume flow rate (actual) [m3/min]
g. Static pressure differential [mm H2O]
h. Inlet temperature [°C]

i. Rated speed [r/min]
j. Maximum allowable speed (at maximum allowable temperature) [r/min]
k. First lateral critical speed [r/min]
l. Rated power [kW]
m. Polar moment of inertia of rotor (WR
]
n. Mass of rotor [kg]
2
) [kg.m
2
6.3. Rotation arrows shall be cast in or attached to each major item of rotating equipment.
6.4. Nameplates and rotation arrows (if attached) shall be of type 300 stainless steel or nickel-
copper alloy (Monel or SABIC approved equivalent). Attachment pins shall be of the same
material. Welding shall not be permitted.
7 Accessories
SABIC shall specify the accessories to be supplied by the vendor.
7.1 Drivers
7.1.1 General
7.1.1.1. The type of driver shall be specified by SABIC. The driver shall be sized to meet the fan
rated point conditions, including external gear and coupling losses, and shall be in
accordance with applicable specifications, as stated in the inquiry and purchase order.
The driver shall be sized and designed for satisfactory operation under the utility and site
conditions specified by SABIC.
7.1.1.2. Anticipated process variations that may effect the sizing of the driver, for example changes
in the pressure, temperature or properties of the fluid handled, and special plant start-up
conditions, shall be specified by SABIC.
7.1.1.3. Forced draft fan driver sizing shall consider fan performance at minimum ambient
temperature and full IGV opening.
7.1.1.4. Induced draft fan driver sizing shall consider possible variations in operating temperature
and gas density, for example a cold start with 100% IGV opening and atmospheric air
condition.
7.1.1.5. The starting conditions for the driven equipment shall be specified by SABIC, and the
starting method shall be mutually agreed upon by SABIC and vendor. The driver‟s starting
torque capabilities shall exceed the speed torque requirements of the driven equipment.
Vendor shall verify that the starting characteristics of the fan and driver are compatible.
The starting torque characteristics of the complete machine train shall be provided to
SABIC.
7.1.2 Motors
7.1.2.1. Unless otherwise specified, motor driven fans shall be direct connected.

7.1.2.2. The motor nameplate rating, exclusive of service factor, shall be at least 110 percent of the
greatest power required, including gear and coupling losses, for any of the specified
operating conditions.
7.1.2.3. Full load and starting current, system WR
2
and motor curves showing torque, current and
power as a function of speed shall be provided for each fan drive.
7.1.2.4. Electric motors in fan drive service shall be in accordance with SES E06-S01 or E06-S02.
Motors for auxiliary equipment shall be in accordance with SES E06-S01.
7.1.3 Turbines
Steam turbine drivers shall conform to SES G06-S02 or G06-S01, as specified by SABIC. Steam
turbine drivers shall be sized to continuously deliver the power required for all specified conditions
while operating at corresponding speed with specified steam conditions.
7.1.4 Gears
Gears shall conform to SES G07-S01 or G07-S02 as applicable and as noted on the data sheets.
7.2 Couplings and Guards
7.2.1. Couplings and guards shall conform to SES G12-S01 if specified on the data sheets.
Special purpose couplings shall only be used on the largest special purpose fans. Smaller
special purpose fans, especially those using general purpose drivers, shall not require
special purpose couplings, unless otherwise specified.
7.2.2. Couplings shall be dry type, spacer couplings and shall be supplied by vendor. Coupling
make may be specified by SABIC, or mutually agreed upon by SABIC and fan vendor.
7.2.3. The coupling spacer length shall be sufficient to allow removal of the coupling hubs and
allow maintenance of adjacent bearings and seals without removal of the shaft or
disturbing the equipment alignment.
7.2.4. Each coupling shall have a coupling guard that sufficiently encloses the coupling and
shafts to prevent any personnel access to the danger zone during operation of the
equipment train. The guard shall be readily removable for inspection and maintenance of
the coupling without disturbing the coupled machines.
7.3 Clutches
7.3.1. Vendor shall provide clutches as required for dual drive (typically one steam turbine and
one electric motor) fans. Vendor shall provide details of the clutch design with the
proposal, for SABIC approval.
7.3.2. Clutches shall be designed to ensure that the idle driver is sufficiently isolated to allow
maintenance and testing to be performed while the fan is being driven by the active driver.
7.3.3. Clutches shall have provision to allow online oil replacement.

7.4 Mounting Plates
7.4.1 General

Fans and drivers shall be furnished with soleplates or a baseplate, as specified on the data
sheets. In the following subsection the term mounting plate refers to both baseplates and
soleplates.
7.4.1.1. The upper and lower surfaces of bearing pedestals and mounting plates shall be machined
flat and parallel after fabrication (and stress relieving, if required) to 100 µm/m. The
maximum surface roughness shall be 3.2 µm Ra.
7.4.1.2. All machinery mounting surfaces on the mounting plates shall extend at least 25 mm
beyond the three outer sides of the equipment feet. All mounting surfaces of one piece of
equipment shall be in the same plane within 40 µm, to prevent soft foot.
7.4.1.3. When epoxy grout is indicated on the data sheets, vendor shall pre-coat all grouting
surfaces of the mounting plates with a catalyzed epoxy primer applied to near white blast
prepared metal surface, prepared to SP10 of the SSPC Code.
7.4.1.4. Anchor bolts shall not be used to fasten machinery to the mounting plates, but may be
used to fasten the fan housing.
7.4.1.5. The fasteners for attaching the components to the mounting plates, and jackscrews for
leveling the pedestal soleplates, shall be supplied by vendor.
7.4.2 Baseplates
7.4.2.1. When a baseplate is specified, SES G11-X02 shall show the extent of equipment and
auxiliaries to be mounted on the baseplate. A baseplate shall be a single fabricated steel
unit unless its exceeds 12 m in length or 3,65 m in width. If a baseplate exceeding those
dimensions is needed, the mating surfaces of the multiple section baseplate shall be
machined and doweled for accurate field assembly.
7.4.2.2. When specified, the baseplate shall be provided with leveling pads or targets, protected
with removable covers, and accessible for field leveling after installation with the
equipment mounted on the baseplate on the foundation.
7.4.2.3. If specified by SABIC, the baseplate shall be suitable for column mounting, that is, of
sufficient rigidity to be supported at specified points, without continuous grouting under
structural members.
7.4.2.4. The baseplate shall be provided with lift lugs for a four point lift. Lifting the baseplate
complete with all equipment mounted shall not permanently distort or otherwise damage
the baseplate or the machinery mounted thereon.
7.4.2.5. The bottom of the baseplate between structural members shall be open. When installed
on a concrete foundation, accessibility shall be provided for grouting under all load bearing
structural members. The mounting pads on the bottom of the baseplate shall be in one
plane, to permit use of a single level foundation. When specified, sub-sole plates shall be
provided by vendor.

7.4.2.6. Non-skid decking shall be provided on the top of the baseplate covering walk and work
areas.
7.4.2.7. Oil reservoirs shall be separate from the baseplate unless otherwise approved by SABIC.
7.4.3 Driver Shim Packs
7.4.3.1. Shim packs shall be located between the driver feet and the baseplate.
7.4.3.2. Shim packs shall be in accordance with API RP 686, Paragraph 5.4.2 and shall be slotted
to straddle the driver hold-down bolts and vertical leveling jackscrews for easy removal.
7.4.4 Leveling Screws
7.4.4.1. Baseplate shall have vertical leveling screws located adjacent to each anchor bolt location.
7.4.4.2. Diameter of leveling screws shall be equal to that of the anchor bolts, as a minimum.
7.5 Controls and Instrumentation
7.5.1 General
7.5.1.1. Controls and instrumentation and any panels shall conform to SES X01-S03.
7.5.1.2. All controls and instrumentation shall be suitable for outdoor installation in the
environmental and hazardous area classification specified on the data sheets.
7.5.1.3. Vendor shall provide sufficient fan performance data to enable SABIC to properly design a
control system for start-up and for all specified operating conditions. When requested by
SABIC, vendor shall review SABIC‟s overall fan control system for compatibility with
vendor furnished control equipment.
7.5.2 Control Systems
7.5.2.1. The fan may be controlled on the basis of inlet pressure, discharge pressure, flow, or a
combination of these parameters. This may be accomplished by suction or discharge
throttling, or speed variation. SABIC shall specify the type and source of the control
signal, its sensitivity and range and the equipment scope to be furnished by vendor.
7.5.2.2. For constant speed drive, the control signal shall actuate an actuator which positions the
inlet damper, outlet damper or inlet guide vanes.
7.5.2.3. For a variable speed drive, the control signal shall act to adjust the set point of the driver‟s
speed control system. Unless otherwise specified, the control range shall be from the
maximum continuous speed to 95 percent of the minimum speed required for any
specified operating case, or 70 percent of the maximum continuous speed, whichever is
lower.
7.5.2.4. The full range of SABIC‟s specified control signal shall correspond to the required
operating range of the driven equipment.
7.5.2.5. Unless otherwise specified, facilities shall be provided to automatically open or close (as
specified) the dampers or variable inlet guide vanes on loss of control signal, and to

 

automatically lock or brake the dampers or vanes in the last position on loss of motive
force, for example air supply or electric power. This is a specific system consideration and
the associated controls shall be arranged to avoid creating hazardous or other undesirable
conditions.
7.5.2.6. Vendor shall furnish and locate the actuators, actuator linkages and actuator shafts for
remote control of the dampers or variable inlet vanes. Actuator output shall be adequate
for the complete range of damper or variable inlet vane positions. The proposed location
of actuator linkages and shafts shall be reviewed with SABIC for consideration of
maintenance access and safety.
7.5.2.7. External position indicators shall be provided for all dampers or variable inlet vanes.
7.5.3 Dampers and Inlet Guide Vanes
7.5.3.1. Frames for inlet dampers (unless integral with the inlet box) and outlet dampers shall be
flanged and drilled air tight steel using tight fitting bolting to connect to the fan or duct
work. Dampers shall be either parallel or opposed blades, as appropriate for the specified
control requirements. Damper blades shall be supported continuously by the shafts. No
stub shafts shall be allowed. Damper shafts shall be sealed or packed to limit leakage,
except for atmospheric air inlet dampers.
7.5.3.2. Vendor shall state the maximum expected leakage through the damper or vanes when
closed at SABIC‟s specified operating temperature and pressure. Stated leakage shall be
estimated at the pressure and temperature differentials expected with the fan operating.
7.5.3.3. The damper or variable inlet vane mechanisms shall be interconnected to a single
actuator. The actuator mechanism shall be designed to allow the dampers or variable
inlet vanes to be manually secured in any position.
7.5.3.4. Variable inlet guide vane actuator mechanisms shall be located outside the flowing gas
stream. The mechanism shall be readily accessible for in-place inspection and
maintenance, and be of bolted attachment construction to permit removal if necessary.
Provision shall be made for lubrication of the mechanism during operation.
7.5.3.5. Inlet dampers and variable inlet vanes shall be continuously welded to the spindle.
7.5.4 Bearing Housing Vibration Detection
7.5.4.1. If specified, one (1) accelerometer transducer per bearing shall be provided to measure
bearing housing vibration.
7.5.4.2. Transducer shall have a minimum sensitivity of 100 mV/G and a frequency range of at
least 1 Hz to 3 kHz.
7.5.4.3. SABIC shall approve location and mounting method of the accelerometer.
7.5.5 Shaft Vibration Detection
If specified, two (2) non-contacting radial vibration probes (at 90separation) per bearing shall be
provided per the data sheet.

If specified, one (1) phase reference shall be provided to facilitate vibration diagnostics and field
balancing.

7.5.6 Sleeve Bearing Temperature Detection
7.5.6.1. If specified, sleeve bearings shall have one Resistance Temperature Detector (RTD) for
each floating bearing and one RTD for each fixed bearing for both radial load and thrust
load.
7.5.6.2. RTDs shall be positioned in the bottom half of the journal bearings, preferably within 10 to
20 degrees of the operating load point and as close as feasible to the back of the Babbitt.
7.5.6.3. Thermocouples shall be as specified on the data sheet.
7.5.6.4. When specified, RTDs shall be 3-wire, platinum, 6 mm (1/4 in.) diameter, DIN type with an
Alpha coefficient of 0.00385. Sheath shall be 300 series stainless steel.
7.5.6.5. RTDs shall have means for spring loading the sensor tip against the bearing backing or
shall be embedded.
7.5.6.6. Leads from the RTDs shall be adequately protected against oil and mechanical damage,
and shall exit the housing through an oil-tight fitting.
7.5.6.7. Weatherproof terminal head with moisture-resistant terminals shall be provided outside the
bearing housing.
7.6 Piping and Appurtenances
7.6.1. Auxiliary piping systems shall include all necessary lube oil, control oil, buffer gas, drain,
vent, steam and water lines attendant to the fan, driver and auxiliaries. Auxiliary piping
shall also include any piping required to connect controls and instruments, and fan blade
cleaning systems on the fan unit or baseplate.
7.6.2. Vendor shall furnish all piping systems, including mounted appurtenances, if these
systems are located within the confines of the main unit base area, or any console base
area of any auxiliary base area. The piping shall terminate with flanged connections at the
edge of any respective base. SABIC shall only furnish interconnecting piping between
equipment groupings and off base facilities.
7.6.3. The design of the piping systems shall achieve the following:
a. Proper support and protection, to prevent damage from vibration or from shipment,
operation and maintenance
b. Proper flexibility and normal accessibility for operation, maintenance and thorough
cleaning
c. Installation in a neat and orderly arrangement adapted to the contour of the machine,
and not obstructing access openings
d. Elimination of air pockets by the use of valved vents or non-accumulating piping
arrangements

e. Complete drainage through low points, without piping disassembly
7.6.4. Lube oil piping shall also be in accordance with SES G03-S01.
7.6.5. Piping systems shall include piping, isolating valves, control valves, relief valves, pressure
reducers, orifices, temperature gages, thermowells, pressure gages, sight flow indicators
and all related vents and drains.
7.6.6. Piping should preferably be fabricated by bending and welding, to minimize the use of
flanges and fittings. Welded flanges shall only be permitted at equipment connections, at
the edge of the base, and for ease of maintenance. The use of flanges at other points
shall be permitted only with SABIC approval. Other than tees and reducers, welded
fittings shall be permitted only to facilitate pipe layout in congested areas. Threaded
connections shall be held to a minimum. Pipe bushings shall not be used.
7.6.7. Pipe threads shall be in accordance with ASME B1.20.1. Flanges shall be in accordance
with ASME B16.5. Slip on flanges shall only be permitted with SABIC approval. A 1.5 mm
gap shall be left between the pipe end and the bottom of the socket fitting in socket welded
construction.
7.6.8. The minimum size of any connection shall be NPS
1
/2.
7.6.9. Piping systems furnished by vendor shall be fabricated, installed in the shop, and properly
supported. Bolt holes for flanged connections shall straddle the horizontal or vertical
center planes of the equipment.
7.6.10. Welding shall be performed by operators and procedures qualified in accordance with
ASME Section IX.
7.7 Inlet Systems
7.7.1. For forced draft fans, the entire inlet stack arrangement, including silencer(s) and transition
piece(s) shall be provided by the fan vendor. Unless otherwise specified, the air intake
shall be 5 m minimum above the rotor centerline. The stack shall be self-supporting on the
fan housing, and shall include intake cap and hood, trash screen, inlet dampers or guide
vanes, inlet boxes, and silencers. All components shall be flanged for assembly. The
stack shall be designed for the wind load shown on the fan data sheet with a 1,0 shape
factor on flat surfaces, or provision shall be made for external bracing to resist wind loads.
Minimum plate thickness for the above components shall be 6 mm.
7.7.2. Inlet trash screen(s) to prevent entry of debris shall be provided for forced draft fans
handling atmospheric air. This screen shall be fabricated from 3 mm minimum diameter
wire with a mesh of 35 mm nominal opening. The screen shall be suitably supported by
cross members. Rain hood(s) shall be provided on vertical inlets. Screen supports and
rain hoods shall be galvanized carbon steel. Trash screen shall be of type 300 series
stainless steel.
7.7.3. An inlet filtration system shall be supplied by the vendor if specified. Even if not specified,
the vendor shall review the specified process conditions and ambient conditions and
advise in the proposal if an inlet filter is recommended or required. Inlet filters may be
disposable element, cleanable element or inertial type.

 

7.7.4. When specified, fans in induced draft service subject to fouling shall be furnished with fan
blade cleaning systems. The fan vendor shall furnish blade cleaning elements, timers and
controls. Cleaning systems shall be designed for air, nitrogen, superheated steam or other
blowing medium as specified and furnished by SABIC. Elements of the blade cleaning
system inside the fan housing shall be made of corrosion resistant material and shall be
adequately supported to resist damage. Positioning of the blade cleaning system shall be
adjustable.
7.8 Silencers
7.8.1. Full details of the proposed silencer shall be submitted with the proposal for SABIC
approval.
7.8.2. The differential pressure drop across each inlet of exhaust silencer shall not exceed 25
mm water column.
7.8.3. Silencers shall be designed to prevent internal damage from acoustic or mechanical
resonance.
7.8.4. Mineral wool fiber insulation shall not be used in silencer construction.
7.8.5. Carbon steel construction shall be of 5 mm minimum thickness plate. Corrosion allowance
and alternative material, if required, shall be specified by SABIC.
7.8.6. Main inlet duct and silencer connections shall be flanged.
7.9 Coatings, Insulation and Jacketing
7.9.1 Coatings
When constructed of carbon steel or cast iron, the equipment shall be coated in accordance with
vendor‟s standard practices. Vendor‟s standard coating procedures shall be included with the
proposal for review.
7.9.2 Insulation and Jacketing
7.9.2.1. When specified by SABIC, vendor shall weld clips or studs on the outside surface of
fan housings and their inlet box(es) and discharge connections, to permit field installation
of insulation by SABIC for thermal conservation, noise abatement, personnel protection or
to maintain the enclosure temperature above the gas dew point. The clips or studs shall
be placed on 300 mm centers and drilled for holding wires, to allow for the installation of
insulation having a thickness of at least 50 mm.
7.9.2.2. When specified, vendor shall include in the proposal a recommended insulation
material and thickness.
7.9.2.3. SABIC‟s insulation and jacketing shall extend over all portions of the fan housing,
inlet box(es) and discharge connections that may reach a normal operating temperature of
75 °C or higher. Insulation shall not interfere with damper or other actuator
mechanism(s).

7.9.2.4. The insulation shall maintain a jacket surface temperature of 65 °C or less under
normal operating conditions. Jackets and insulation shall be designed to minimize
possible damage during removal and replacement. SABIC shall specify the type of
insulation and jacketing. This material shall not be supplied by vendor unless otherwise
specified.
7.10 Turning Gear
Turning gear shall be provided whenever specified by SABIC or required by vendor. The turning
device may be manually or automatically engaged and shall automatically disengage when the fan is
placed in service. The turning gear shall be driven by an electric motor.
8 Inspection and Testing
8.1 General
8.1.1. Vendor shall provide SABIC with advance notification of certain shop inspections and
testing as outlined in the purchase order. SABIC shall have entry, after prior notification,
to all vendor and sub-vendor plants where work upon or testing of the equipment is in
progress. Vendor shall notify sub-vendors of SABIC‟s inspection requirements.
8.1.2. When shop inspection and testing have been specified by SABIC, SABIC and vendor shall
meet to coordinate manufacturing hold points and inspectors‟ visits. See the data sheets
to determine the required inspection, testing and extent of SABIC participation. Vendor
shall provide sufficient advance notice to SABIC before conducting any inspection or test
that SABIC has specified to be witnessed or observed. In each instance the actual
number of calendar days considered to be sufficient notice shall be established by mutual
consent of SABIC and vendor.
8.1.3. SABIC shall specify the extent of their participation in the testing. The following terms may
be used to define participation:
a. Witness means that a hold shall be applied to the production schedule and the test
carried out with SABIC in attendance
b. Observed means that SABIC requires notification of the test timing; however, the test
shall be performed as scheduled and if SABIC is not present, vendor can proceed with
the next step
8.1.4. SABIC shall have access to vendor‟s quality program for review.
8.2 Inspection
8.2.1 General
8.2.1.1. Vendor shall keep the following data available for at least 20 years for examination or
reproduction by SABIC:
a. Necessary certification of materials, for example mill test reports
b. Test data to verify that the requirements of the specification have been met

 

c. Results of documented tests and inspections, including fully identified records of all
heat treatment and radiography
d. When specified, final assembly running clearances and run-outs
e. Running test data to verify that the requirements of the specification are being met.
8.2.1.2. All coating of surfaces shall be deferred until the specified inspection of that part is
completed.
8.2.1.3. SABIC shall specify parts which shall be subjected to surface and sub-surface inspection
and the type of inspection required, for example magnetic particle, dye penetrant,
radiographic, ultrasonic or other.
8.2.1.4. SABIC shall make an inspection for cleanliness of the equipment and all piping and
appurtenances furnished by or through vendor prior to final assembly.
8.2.1.5. When specified, hardness of parts, welds and heat affected zones shall be verified as
being within the allowable values by testing of the parts. Method, extent, documentation
and witnessing of test shall be mutually agreed upon by SABIC and vendor.
8.2.2 Material Inspection
8.2.2.1 General
When radiographic, ultrasonic, magnetic particle or liquid penetrant inspection of welds or materials is
required or specified, the criteria in ‎8.2.2.2 to ‎8.2.2.4 shall apply unless other criteria are specified by
SABIC. Cast iron shall be inspected in accordance with ‎8.2.2.3 and ‎8.2.2.4, as applicable. Welds,
cast steel and wrought materials shall be inspected in accordance with ‎8.2.2.2 to ‎8.2.2.4, as
applicable.
8.2.2.2 Radiography
Radiography shall be in accordance with ASTM E 94. The acceptance standard for welded
fabrications shall be in accordance with ASME BPVC Section VIII, UW-51 (100 percent) or UW-52
(spot). The acceptance standard used for castings shall be in accordance with ASME BPVC
Section VIII, Div 1, Appendix 7.
8.2.2.3 Ultrasonic Inspection
Ultrasonic inspection shall be in accordance with ASME Section V, Article 5 and 23. The acceptance
standard use for welded fabrication shall be in accordance with ASME BPVC Section VIII, Div 1,
Appendix 12. The acceptance standard use for castings shall be in accordance with ASME BPVC
Section VIII, Div 1, Appendix 7.
8.2.2.4 Liquid Penetrant Inspection
Liquid penetrant inspection shall be in accordance with ASME Section V, Article 6. The acceptance
standard used for welded fabrications shall be in accordance with ASME BPVC Section VIII, Div 1,
Appendix 8 and ASME Section V, Article 24. The acceptance standard used for castings shall be in
accordance with ASME BPVC Section VIII, Div 1, Appendix 7.

8.3 Shop Assembly
Fans shall be shop assembled prior to shipment. Drivers and other auxiliaries shall be included in the
shop assembly and mock-up when specified. If disassembly is required for shipment, mating parts
shall be suitably match marked and tagged for field reassembly. SABIC shall be notified as least 5
working days prior to completion of the shop assembly, to permit inspection prior to disassembly
(when required) and shipment.
8.4 Testing
8.4.1 General
8.4.1.1. Equipment shall be tested in accordance with ‎8.4.2. Other tests which may be specified
by SABIC are described in ‎8.4.3.
8.4.1.2. At least 6 weeks before the first scheduled mechanical running test, the vendor shall
submit to SABIC for review and comment detailed procedures for the mechanical running test
and all specified optional tests, and acceptance criteria for all monitored parameters.
8.4.1.3. Vendor shall notify SABIC not less than 15 working days prior to the date the equipment
shall be ready for test.
8.4.1.4. Equipment for specified tests shall be provided by vendor.
8.4.1.5. Acceptance of shop tests shall not constitute a waiver of requirements to meet field
performance under specified operating conditions, nor shall inspection relieve vendor of any
responsibilities.
8.4.2 Hydrostatic Test
8.4.2.1. Pressure containing parts other than the fan housing, but including auxiliaries, shall be
hydrostatically tested with liquid at a minimum of 1,5 times the maximum allowable working
pressure (MAWP) but not less than 150 kPa(g). The test liquid shall be at a higher
temperature than the nil ductility transition temperature of the material being tested.
8.4.2.2. Where applicable, tests shall be in accordance with the ASME Code. In the event that a
discrepancy exists between the ASME code test pressure and the test pressure in this
specification, the higher pressure shall govern.
8.4.2.3. The chloride content of liquids used to test austenitic stainless steel materials shall not
exceed 50 parts per million. To prevent deposition of chlorides as a result of evaporative
drying, all residual liquid shall be removed from tested parts at the conclusion of the test.
8.4.2.4. Tests shall be maintained for a sufficient period of time to permit complete examination of
parts under pressure. The hydrostatic test shall be considered satisfactory when neither leaks
nor seepage through the casing or casing joint is observed for a minimum of 30 minutes.
Large heavy casting may require a longer testing period to be agreed upon by SABIC and
vendor.

8.4.3 Optional Tests
8.4.3.1 Mechanical Running Test
When mechanical running test is specified, the testing shall include the following:

a. The fan shall be operated from 0 to 115 % of rated speed for variable speed drives,
and at 100 % of rated speed for constant speed drives. Operation shall be for an
uninterrupted period of at least two hours after all measurements have stabilized, to
check bearing performance and vibration.
b. All warning, protective and control devices used during the test shall be checked,
and adjustments shall be made as required
c. During the mechanical running test, the mechanical operation of all equipment being
tested, and the operation of the test instrumentation, shall be satisfactory. The
measured unfiltered vibration shall not exceed the limits set by this specification in
‎4.8.8 and shall be recorded throughout the operating speed range.
d. Hydrodynamic bearings shall be removed, inspected, and when applicable,
reassembled after the mechanical running test is completed
e. Bearings used in oil mist lubrication systems shall be pre-lubricated before testing
f. All oil pressures, viscosities and temperatures shall be within the range of operating
values recommended in vendor‟s operating instructions for the specific unit being
tested. For pressure lubrication systems, oil flow rates for each bearing housing
shall be measured.
8.4.3.2 Performance Test
When a shop or field performance test is specified, the details and extent of the test shall be
developed jointly by SABIC and vendor. Typical testing procedures are contained in AMCA 203 and
210 and ASME PTC 11. The fan performance shall meet all operating conditions specified on the
data sheets and shall be within the following tolerances:
a. For variable speed fans, the static pressure and capacity shall be met at the fan rated
point in a way that the power required is not exceeded by more than 4 %. Where changes
in speeds are needed to meet static pressure requirements, vendor shall adjust the
operating range accordingly.
b. For constant speed fans, the specified capacity shall be met with the understanding that
the static pressure rise shall be met within +5 and -0 % of that specified. The power shall
not exceed stated power by more than 4 %.
8.4.3.3 Complete Unit Test
When specified, components that make up a complete unit, for example fans, gears, drivers and
auxiliaries, shall be tested together during the mechanical running test. The complete unit test shall
be performed in place of or in addition to separate tests of individual components specified by SABIC.

8.4.3.4 Pressure Test
The casing (with or without end seals installed) shall be pressurized with air to the MAWP or to
135 kPa(g), held at this pressure for a minimum of 30 minutes, and subjected to a soap bubble test or
other SABIC approved test, to check for gas leaks. The test shall be considered satisfactory when no
casing or casing joints leaks are observed.
9 Preparation for Shipment

9.1. Equipment shall be suitably prepared for the type of shipment specified, including blocking
of the rotor when necessary. Blocked rotors shall be identified by means of corrosion
resistant tags attached with stainless steel wire. The preparation shall be suitable for a
period of 6 months outdoor storage from the time of shipment, with no disassembly
required before operation, except for bearing and seal inspections. If storage is
contemplated for longer periods, SABIC shall consult with vendor regarding procedures to
be followed.
9.2. Vendor shall provide SABIC with the instructions necessary to preserve the integrity of the
storage preparation after the equipment arrives at the job site and before start-up.
9.3. Preparation for shipment shall be made after all testing and inspection of the equipment
has been accomplished, and the equipment has been approved by SABIC. The
preparations shall include the following:
a. Exterior surfaces, except for machined surfaces, shall be given at least one coat of
the manufacturer‟s standard paint. The paint shall not contain lead or chromates.
b. Exterior machined surfaces, except for corrosion resistant material, shall be coated
with a suitable rust preventative
c. The interior of the equipment shall be clean, free from scale, welding spatter and
foreign objects. The interior shall be sprayed or flushed with a suitable rust
preventative that can be removed with solvent. As an alternative, SABIC may
specify a permanent suitable coating.
d. Internal steel areas of bearing housing and carbon steel oil systems‟ auxiliary
equipment, for example reservoirs, vessels and piping, shall be coated with a
suitable oil soluble rust preventative.
e. All flanged auxiliary piping connections shall be provided with metal closures of
5 mm minimum thickness with elastomeric gaskets and at least four full diameter
bolts. For studded openings, all the nuts needed for the intended service shall be
used to secure closures. Each opening shall be car sealed to prevent removal of the
protective cover without the seal being broken.
f. All threaded openings shall be provided with steel caps or long shank steel plugs.
Nonmetallic plugs shall not be used.
g. All auxiliary piping connections that have been beveled for welding shall be provided
with closures designed to prevent entrance of foreign materials and damage to the
bevel.

 

h. Inlet and discharge duct connections on fans shipped assembled shall be adequately
covered to prevent entrance of foreign materials and damage to the duct connection.
Vendor‟s proposal shall state how duct connections shall be protected.
i. The rotor shall be treated with a rust preventative if the fan is to be field assembled,
and the rotor shall be suitably crated for the specified shipment. Suitable 3 mm
minimum thickness lead sheeting shall be used between the rotor and cradle at the
support areas. The rotor shall not be supported at journals.
j. The center of gravity, the lifting points and the lifting lugs shall be clearly identified.
k. Equipment shall be identified with the item and serial numbers. All material shipped
separately shall be identified with securely affixed corrosion resistant metal tags
indicating the item and serial number for which it is intended.
l. One copy of vendor‟s standard installation instructions shall be packed and shipped
with the equipment.
10 Vendor Data
10.1 Proposals
Vendor‟s proposal shall include the information listed below. Vendor shall include the time schedule
for transmission of drawings, curves and data.
a. Copies of the data sheets with complete vendor‟s information entered.
b. Complete performance curves to fully define the envelope of operation and the
specific guarantee point.
c. Utility requirements, for example steam, water, electricity, air and gas; driver ratings;
and net loads. Approximate data shall be clearly defined as such. This information
shall be entered on the data sheets where applicable.
d. Net and maximum operating mass, maximum erection mass with identification of the
item. These data shall be stated individually where separate shipments, packages
or assemblies are involved. These data shall be entered on the data sheets where
applicable.
e. Preliminary outline and arrangement drawings and schematic diagrams.
f. Typical cross sectional drawings and literature to fully describe details.
g. Details of shaft seals.
h. A statement of the fixed number of weeks to effect shipment after receipt of the
order. A separate time shall be stated for manifold shipment, as in the case of
separate packages, assemblies or multiple units.
i. A statement of vendor‟s promised times after order placement for transmittal of the
contract data. This information shall be presented in the form of an explicit schedule.
j. A list of spare parts recommended for normal maintenance purposes. SABIC shall
specify any specific requirements for long term storage.

k. An itemized list of the special tools included.
l. The tests and procedures for materials as required by this specification.
m. A statement of the rate for furnishing a competent erection supervisor, plus an
estimate of the length of time the erection supervisor‟s services might be required
under normal conditions.
n. An outline of necessary special weather and winterizing protection required by the
fan, the auxiliaries and the driver for start-up, operation and idleness. Vendor shall
quote separately for protective items they propose to furnish.
o. Any start-up, shutdown or operating restrictions required to protect the integrity of the
fan, for example maximum temperature rise or cooling rate for the rotating assembly,
and maximum rotating speed
p. Noise emission data for the quoted equipment according to S20-G01.
10.2 Contract Data
10.2.1 Drawings
10.2.1.1 SABIC shall state in the inquiry and in the purchase order the number of prints required
and the times within which they are to be submitted by vendor.
10.2.1.2 Review of vendor‟s drawings shall not constitute permission to deviate from any
requirements in the purchase order, unless specifically agreed upon in writing. After the drawings
have been reviewed, vendor shall furnish copies in the quantity specified. All drawings shall be clearly
legible.
10.2.1.3 Typical drawings shall not be acceptable. The following information shall be provided on
the drawings:
a. SABIC‟s order number on every drawing.
b. SABIC‟s equipment number on every drawing.
c. The mass of:
 Each assembly
 The heaviest piece of equipment which has to be handled for erection
 Significant items that have to be handled for maintenance
d. All principal dimensions, including those required for SABIC‟s foundation, piping design,
maintenance clearances and dismantling clearances.
e. The direction and magnitude of the residual unbalance for all balancing planes of the rotor,
as well as the location of the center of gravity of the rotor.
f. The direction of rotation.
g. The size, type, location and identification of all connections to be supplied by SABIC,
including vents, drains, lubricating oil, and instruments. Vendor‟s plugged connections
shall be identified.

 

h. When applicable, the make size and type of couplings, and the location of guards and their
coverage.
i. Complete bill of materials covering vendor‟s entire scope of supply.
j. A list of reference drawings.
k. Special weather protection and climatization features, if any.
10.2.1.4 Vendor shall supply schematic diagrams of each system in vendor‟s scope of supply, plus
outline drawings and specifications for the components thereof.
10.2.1.5 Vendor shall supply cross sectional or assembly type drawings for all equipment furnished,
showing all parts, running fits, clearances and balancing data required for erection or maintenance.
Typical drawings shall not be acceptable.
10.2.1.6 Vendor shall provide design details of dampers or guide vanes, as applicable, for SABIC
approval.
10.2.2 Performance Curves
Vendor shall provide complete performance curves to encompass the map of operation, with any
limitations indicated thereon. As a minimum, the vendor shall provide, head vs. capacity and power
vs. capacity curves for 100 %, 60 % and 20 % damper control settings and an efficiency vs. capacity
curve. Where gas temperature variations are specified, separate curves shall be provided for
maximum, minimum and mid-point temperatures.
10.2.3 Data
10.2.3.1. Vendor shall provide full information to enable completion of the data sheets, first for
„as purchased‟ and then „as built‟.
10.2.3.2. Vendor shall make the following information available to SABIC:
a. Vendor‟s physical and chemical data from mill reports or certifications of materials.
b. Completed as built data sheets.
c. The required lateral and torsional critical speed analysis reports.
d. Certified balancing certificate, that contains at least the following information:
i. Rated service speed of rotor
ii. Balancing speed
iii. Total mass of rotor
iv. Static mass at each bearing location (on sketch of rotor)
v. Bearing spacing (on sketch of rotor)
vi. Distance of balancing planes relative to bearing locations (on sketch of rotor)
vii. Location of phase reference mark relative to keyway or other unique position
on rotor
viii. Balancing standard and permissible values of unbalance per balancing plane

ix. Magnitude and phase of initial and final unbalance per balancing plane
e. Certified residual unbalance work sheet (see ‎4.8.3)
f. Certified rotor run-out measurement results (see ‎4.8.4 and ‎4.8.5)
10.2.3.3. Vendor shall state thrust and radial bearing clearances.
10.2.3.4. Apart list shall be furnished for all equipment supplied, and shall include pattern, stock
or production drawing numbers and materials of construction. The list shall completely
identify each part, to allow SABIC to determine the interchangeability of parts with
other equipment furnished by the same manufacturer. Standard purchased items shall
be identified by the original manufacturer‟s part numbers.
10.2.3.5. No later than 5 days after the scheduled shipping date, vendor shall furnish the
required number of instruction manuals for the equipment and any auxiliaries and
instruments provided. The manual shall include legible drawings for the specific
equipment, part lists and completed data sheets. It shall include instructions covering
installation, final tests and checks, start-up, shutdown, operating limits and operating
and maintenance procedures. The recommended clearances and maximum and
minimum design clearance shall be clearly stated.
10.2.3.6. Vendor shall submit a supplementary proposal for spare parts other than those
included in the original quotation. This supplementary proposal shall include
recommended commissioning spare parts, cross sectional or assembly type drawings,
part numbers, materials, prices and delivery. Part numbers shall identify each part for
interchangeability purposes. Standard purchased items shall be identified by the
original manufacturer‟s numbers. This supplementary proposal shall be forwarded to
SABIC promptly after receipt of approved drawings, and in time to permit order and
delivery of parts prior to field start-up.
10.2.3.7. When a shop mechanical running test is specified, certified copies of the shop log,
performance data and other test data agreed upon, shall be submitted to SABIC prior
to shipment.
10.2.3.8. When a performance test is specified, certified copies of the shop log containing all
performance data shall be submitted to SABIC.
10.2.4 Vendor Information
10.2.4.1. Vendor shall complete vendor information data sheet detailing the time schedule for
transmission of drawings, curves and data as agreed to at time of order, and the exact
number of copies required by SABIC.
10.2.4.2. When specified, progress reports shall be submitted to SABIC at the specified
frequency. The reports shall include engineering and manufacturing on all major
components.