1. PURPOSE………………………………………………………………….2. GENERAL 3. ADDENDA The following section, subsection numbers refer to API 611
Section 1 – General …………………………………………………..1.1 Scope 1.2 Alternate Designs 1.3 Conflicting Requirements………………………..1.5 Referenced Publications
Section 4 – Basic Design 4.1 General ………………………………………………..
4.2 Pressure Casings 4.3 Casing Appurtenances 4.4 Casing Connections ……………………………….4.6 Rotating Elements 4.7 Seals 4.8 Dynamics ……………………………………………..4.9 Bearings and Bearing Housings 4.10 Lubrication 4.11 Materials……………………………………………..4.12 Nameplates and Rotation Arrows
Section 5 – Accessories 5.1 Gear Units …………………………………………….5.2 Couplings and Guards 5.3 Mounting Plates 5.4 Controls and Instrumentation…………………..5.5 Piping and Appurtenances 5.7 Insulation and Jacketing
Section 6 – Inspection and Testing ……………………………..6.1 General 6.2 Inspection
6.3 Testing …………………………………………………Section 7 – Vendor’s Data
7.2 Proposals 7.3 Contract Data ……………………………………….
1. Purpose
American Petroleum Institute (API) standard 611, Fourth Edition is adopted as a SABIC Engineering
Standard with the following addendum.
2. General
Steam turbines manufactured to this standard shall conform to API 611, Fourth Edition except as modified
herein, or as set forth on the Data Sheets, Project Specifications or by the Purchase Order.
3. Addenda
The following section, subsection, paragraph numbers refer to API 611, Fourth Edition.
Section 1 – General
1.1 Scope
1.1.2.3 Add the following new paragraph:
General purpose steam turbines shall be supplied by vendors qualified by experience in manufacturing the
units proposed. To qualify, the vendor shall have manufactured at least two turbines of comparable speed,
power rating, and steam conditions. The turbines shall have completed at least 8000 hours of continuous
operation satisfactorily.
1.2 Alternate Designs
Add the following sentence:
Metric fasteners constitute alternative design features and shall be cited as exceptions to the vendor’s
proposal. Metric flanges are not acceptable.
1.3 Conflicting Requirements
Add the following sentence:
Any conflict(s) between this standard, SES and industry standards, engineering drawings, and contract
documents shall be resolved at the discretion of SABIC.
1.5 Referenced Publications
1.5.2 Add the following paragraph:
The following documents are part of this addendum. The latest issues, amendments, and supplements to
these documents shall apply unless otherwise indicated.
SABIC Engineering Standards (SES)
G03-S01 Lubrication, Shaft Sealing, Control Oil Systems and Auxiliaries
G06-T01 Shop Inspection and Testing of Steam Turbines
G07-S01 General Purpose Gear Units
G19-S01 Machinery Protection Systems
S20-G01 Plant Equipment Noise Levels
Section 4- Basic Design
4.1 General
4.1.4 Add:
Turbines shall be sized in accordance with the following requirements:
Turbine rated power
>110% of driven equipment rated power including mechanical loss of power transmission unit.
>110% of driven equipment kW at any specified alternative operating point including mechanical loss.
Notes:
1) Maximum BHP at entire performance curve of centrifugal pumps is considered to be BHP at alternative
point, if parallel operation of pumps is anticipated.
2) BHP at the pump relief-valve setting with maximum pumping liquid viscosity is considered to be BHP at
alternative point for positive-displacement pumps.
4.1.12 An exception to the requirement is as follows:
The equipment furnished by the vendor shall not exceed a noise level of 85 dBa measured at 1 meter. See
SES S20-G01.
4.1.14 Modify the paragraph as follows:
Turbines and auxiliaries shall be suitable for outdoor installation and the following provisions shall be
included where equipment requires protection from the site environment.
a. Dust seal or cover
b. Filter for breather
4.2 Pressure Casings
4.2.3 Add the following sentence:
Unless otherwise approved by SABIC, axially split casings shall be designed to permit inspection and
replacement of the bearings and outer glands without the removal of the upper half.
4.2.5 Add the following sentence:
Radially split horizontal turbines may be used for ratings up to 30 kW with prior approval from SABIC.
4.2.7 Add the following sentence:
Drain connections shall be piped to open atmospheric drain lines and shut-off valves shall be provided.
Drains shall not be manifolded, but shall be grouped as much as practicable.
4.2.8 Add the following sentence:
Pressure gauge connections of multi-stage turbines shall be provided with valves and terminated with
flanges.
4.2.13 Add the following sentence:
The equipment feet shall be equipped with vertical jackscrews.
4.2.15 Add the following new paragraph:
The equipment shall be equipped with horizontal movement jackscrews on all feet.
4.3 Casing Appurtenances
4.3.1 Add the following new paragraph:
All turbines shall be protected against blocked exhaust by a relief valve in the piping supplied by the
Purchaser. The turbine Vendor shall advise the steam flow rate for minimum inlet conditions and maximum
exhaust pressure at the turbine rated power for this valve.
4.4 Casing Connections
4.4.1 Add the following:
The preferred arrangement shall allow rotor removal without disassembly of piping.
4.6 Rotating Elements
4..6.1 Rotors
4.6.1.2 Add the following sentence:
When auto-start service is specified, turbine rotors shall have integrally forged shafts and disks, or with
SABIC’s approval, separate shafts and disks of forged material with a greater than normal shrink fit.
4.6.3 Blading
4.6.3.2 Add the following sentence:
Turbines using integral blade/disk design require prior SABIC’s approval.
4.7 Seals
4.7.4 Add the following sentence:
Gland condensors and ejectors shall be provided for multi-stage turbines having labyrinth seals or a
combination of carbon ring/labyrinth gland packing.
4.8 Dynamics
4.8.2 Lateral Analysis
4.8.2.1 Add the following sentence:
Lateral critical speed analysis shall be performed for all multi-stage turbines. A rotor response calculation
shall be performed for multi-stage turbines running over 5,000 rpm.
4.8.3 Torsional analysis
4.8.3.5 Add the following sentence:
A torsional analysis and report shall be required when the train includes a gear or reciprocating
compressor.
4.8.4 Vibration and Balancing
4.8.4.6 Add the following sentence:
Mechanical runout shall be measured and recorded for all rotor assemblies.Electrical runout shall be
measured and recorded only for rotors specified as requiring non-contacting shaft vibration probes.
4.9 Bearings and Bearing Housings
4.9.1.c Add the following new paragraph:
Hydrodynamic radial bearings shall be provided for all multi-stage turbines and single stage turbines for
rating more than 30 kW (40 HP).
4.9.2 Modify second sentence as follows:
Multistage turbines shall be provided with hydrodynamic thrust bearings.
4.9.21 Add the following sentence:
Seals shall be “INPRO” or equivalent. Equivalent design shall be subject to SABIC’s approval.
Bearing housing shall be Nitrogen purged and equipped with a breather in accordance with the OWNER’s
standard.
4.9.23 Add the following sentence:
A separate oil level sight glass shall be provided for oil-lubricated non-pressure-fed bearing housings.
4.9.31 Add the following sentence:
Use of copper or copper alloy for cooling coils shall require SABIC approval.
4.9.32 Add the following sentence:
Provisions for mounting radial vibration probes and axial probes are required for all multi-stage turbines.
The connections for probe mountings shall be plugged, if not used.
4.9.33 Add the following sentence:
All steam turbines with hydrodynamic thrust bearings shall have metal temperature monitoring on both the
active and inactive sides of the bearing.
4.10 Lubrication
4.10.4 Add the following sentence:
The lubrication system shall be designed to prevent any detrimental effects on the bearings when the
turbine is running continuously at the minimum specified speed.
4.10.6 Pressurized lubrication shall be applied to the following case:
a. If the maximum continuous speed is equal to or greater than 5000 rpm
b. If the turbine rated kW is equal to or greater than 500 kW
c. If normal inlet steam temperature exceeds 400°C
d. If pressurized lubrication system is applied to the driven equipment and/or the speed reduction
gear unit.
4.10.6.4 Add the following:
A single oil cooler shall be used in services with spare units. In services without spare units, dual oil coolers
with transfer valves shall be furnished.
4.10.6.5 Add the following:
Duplex filters with transfer valves, and a jumper line with valve and orifice, shall be provided. A differential
pressure gauge measuring the pressure drop across the oil filters shall be provided.
4.10.6.9 Add
A standby pump should be considered for turbines to be used for utility service such as boiler feed water or
cooling water, and for turbines having a rating equal to or greater than 500 kW.
4.10.6.10 Revise
For units over 50 hp, and when specified, a sight flow indicator in each bearingoil drain line.
4.10.6.11 Deletion
Delete the words “When specified”.
4.10.6.12 Deletion
Delete the words “When specified”.
4.10.6.13 Add the following:
Pressurized lubrication system shall be provided with:
a) A low oil pressure shut-down transmitter
b) Temperature indicators for return lube oil line at each bearing housing.
4.11 Materials
4.11.1 General
4.11.1.4 Add the following sentence:
Cast blades are not acceptable. Valve discs and stems for governor and trip valves shall be 12-13 percent
Cr steel. Materials of mating surfaces shall be dissimilar in composition or hardness.
4-11.1.5 Add the following sentence:
Linkage joints shall use low-friction or self-lubricating material.
4.11.1.7 Add the following sentence:
Copper or copper alloys shall not be used for any component exposed to the atmosphere. Austenitic
stainless steel materials shall not be used for turbine internal components or for any component in contact
with the steam.
4.11.3 Welding
4.11.3.5 Add the following new paragraph
Major repairs to castings shall not be made without prior SABIC approval.
Defects that result in major casting repairs are:
a. Those that cause the casting to leak during hydrostatic testing.
b. Those that result in repair cavities that exceed 20% of the casing wall thickness or 25 mm (1 in)whichever is less.
c. Those that result in a repair area that exceed 65 cm
(10 in).
All major defects and subsequent repairs shall be documented on weld repair maps. Weld repair maps
2
shall specify defect location, size, the weld and NDT procedures used to make the repairs.
Welders shall be qualified in accordance with ASME Section IX.
4.11.3.6 Add the following new paragraph:
All casting repair welds shall be examined using the same nondestructive testing methods that were
employed to inspect the casting.
4.11.3.7 Add the following new paragraph:
Weld repairs are not allowed on rotors.
4.12 Nameplates and Rotation Arrows
4.12.2 Add the following sentence:
The nameplate shall be in English language.
Section 5 – Accessories
5.1 Gear Units
5.1.3 Add
Separate gear units shall be of the double helical type.
5.2 Couplings and Guards
5.2.1 Add the following sentence:
Metallic disc-pack or diaphragm couplings shall be supplied on all turbines.
5.2.2 Add the following sentence:
Couplings shall be designed to withstand running-in and slow roll misalignment. Couplings shall be
capable of absorbing twice the maximum axial thermal growth. Spacer couplings shall be provided as
required, to permit seal and bearing replacement on the turbine and driven equipment without rotor
removal or moving equipment.
5.2.7 (Clarification)
Cylindrical fit is required.
5.3 Mounting Plates
5.3.1 General
5.3.1.2.8 Add the following sentence:
Shim packs shall cover the full foot area.
5.3.2 Baseplate
5.3.2.1 Add the following sentence:
Unless otherwise specified, drain-rim type baseplates shall be provided. Baseplate design shall not allow
forming of stationary liquid pools on the surface.
5.4 Controls and Instrumentation
5.4.1 General
5.4.1.2 Add the following sentence:
All controls, instrumentation, and enclosures shall be suitable for the specified area classification and
environmental exposure.
5.4.1.5 The decision is as follows:
Hand operated nozzle control valves shall be provided
5.4.2 Control Systems
5.4.2.2 Add the following sentence:
Electronic governors are preferred. Dual speed sensors shall be provided as a minimum. NEMA class D
governors per NEMA SM23 are required for the following services:
a. Instrument air compressor
b. Boiler feed water drives
c. All centrifugal compressor drives
d. All drives for pumps operating in parallel
5.4.3 Instrumentation
5.4.4.1 Add the following sentence:
The tachometer shall be of the digital type, which shall be located to allow the operator to observe it when
setting the trip device or speed adjustments.
5.4.5 Alarms and Shutdowns
5.4.5.3 Alarm and Trip Switches
5.4.5.3.2 (Substitution)
Where switches are normally specified, transmitters shall be used in place of the switches. The transmitter
manufacturer will be specified by the OWNER.
5.4.5.3.6 Add the following new paragraph:
Alarm and shutdown switches shall be arranged to permit testing of the control circuits, and testing of the
actuating element where possible, without interrupting normal operation.
5.5 Piping and Appurtenances
5.5.1 General
5.5.1.4 Add the following sentence:
Steam drain lines (for example: casing drains, steam chest drain or trip valve drain) shall be provided with
valves and terminated with flanged connections at the edge of the baseplate. Gland leak steam piping shall
be manifolded and terminated with flanged connection at the edge of the baseplate. Cooling water piping
shall be arranged in series, provided with a sight flow glass and inlet/outlet valves, and terminated with
flanged connections at the edge of the baseplate.
5.5.1.5 Add the following new paragraph:
f. Piping adjacent to insulated equipment shall be arranged to avoid interference with the insulation. Piping
shall be designed to permit servicing of the equipment with a minimum need for breaking connections or
stripping the insulation.
5.5.2.1 Revise
Oil drain lines shall be sized to run no more than half full when flowing at a velocity of 1 foot per second (0.3
meter per second) and shall be arranged to ensure good drainage (recognizing the possibility of foaming
conditions). Drain lines depending on gravity flow shall slope downward, a minimum of 1:25 (1/2 inch per
foot), toward the reservoir. If possible, laterals (not more than one in any transverse plane) should enter the
drain headers at 45-degree angles in the direction of the flow.
5.7 Insulation and Jacketing
5.7.1 Substitute the paragraph as follows:
The turbines shall be supplied with removable blanket-type, asbestos free insulation that extends over all
portions of the casing and is able to reach a normal operating temperature of 74°C (165°F) or higher. The jacket shall consist of insulating material encapsulated in a high temperature fabric with protective wire
mesh. Jacket fasteners, wire mesh, and fittings shall be made of stainless steel.
Section 6 – Inspection And Testing
6.1 General
6.1.2 Add the following sentence:
Shop inspection and testing shall be in accordance with SES G06-T01, Shop Inspection and Testing of
Steam Turbines.
6.2 Inspection
Shop inspection and testing shall be in accordance with SES G06-T01, Shop Inspection and Testing of
Steam Turbines.
6.3 Testing
6.3.1 General
6.3.1.1 Add the following sentence:
Requirements for documentation and witnessing of tests shall be as specified on the turbine data sheets.
6.3.2 Hydrostatic Test
6.3.2.6 Add the following new paragraph:
The chloride content of liquids used to hydrotest austenitic stainless steel materials shall not exceed 30
parts per million.
6.3.3 Mechanical Running Test
6.3.3.1.2 The decision is as follows:
For pressure lubrication systems, oil flow rates for each bearing housing shall be determined.
Section 7 – Vendor’s Data
7.2 Proposals
7.2.3h Add the following sentence:
The proposal for spare parts shall be with proposed method of protection from corrosion during shipment
and subsequent storage.
7.2.3p Add the following new paragraph:
The Vendor’s proposal shall also address slow roll, preheat, drainage, and other requirements or
limitations for turbines in standby service.
7.2.4 (Deletion)
Delete the words “If specified”.
Add:
Vendor shall additionally provide curves for steam flow vs. thrust bearing load.
7.3 Contract Data
7.3.2 Add the following new paragraph:
Allowable forces and moments for the turbine nozzles shall be shown on the certified outline drawings.
7.3.6 Installation and Instruction Manuals
7.3.6.1 Add the following new paragraph:
Installation and instruction manuals shall have a checklist of conditions for starting the unit.
(Addition)
The cover sheet provided in front of the manual shall include the following information:
1. Purchase order number
2. Item number
3. OWNER and user (if different) names
4. Job name and number
5. Vendor order number
6. Turbine model and serial number
7. Location of parts and service center nearest to the installation site
All of the above materials, plus any Sub-vendor’s information, must be submitted in a single, suitably
bound, manual by the Vendor. Instructional data are not to be submitted in a piecemeal fashion.