1. Scope ……………………………………………………………………………………
2. References ……………………………………………………….
3. General ……………………………………………………………………………………
3.1. Units of Measurement …………………………..
3.2. Conflicts ……………………………………………………….
3.3. Buyer Exceptions ……………………………………………………….
3.4. Vendor Exceptions ……………………………………………………….
4. Meter Stations ……………………………………………………….
4.1. Definition ……………………………………………………….
4.2. Custody Transfer Metering …………………………..
4.3. Meter Run ……………………………………………………….
4.4. General Guidelines ……………………………………………………….
4.5. Design, Construction, And Installation …………………………..
5. Meters ……………………………………………………………………………………
5.1. General Guidelines ……………………………………………………….
5.2. Design ……………………………………………………….
5.3. Construction ……………………………………………………….
5.4. Installation ……………………………………………………….
6. Meter Prover ……………………………………………………….
6.1. General Guidelines ……………………………………………………….
6.2. Design ……………………………………………………….
6.3. Construction ……………………………………………………….
6.4. Installation ……………………………………………………….
7. Instrumentation ……………………………………………………….
7.1. General Guidelines ……………………………………………………….
7.2. Design, Construction and Installation …………………………..
8. Electrical ……………………………………………………………………………………
8.1. General Guidelines ……………………………………………………….
9. Valves ……………………………………………………………………………………
9.1. General Guidelines ……………………………………………………….
9.2. Design and Installation …………………………..
10. Fluid Conditioning Devices (F.C.) …………………………..
10.1. General Guidelines:……………………………………………………….
10.2. Design and Installation …………………………..
11. Documentation ……………………………………………………….
11.1. General ……………………………………………………….
12. Testing and Inspection ……………………………………………………….
12.1. General ……………………………………………………….
13. Revision History ……………………………………………………….
1. Scope
This standard is one of the SES R05 series of Flow Measurement standards. It establishes the
minimum guidelines for the design, construction, and installation of custody transfer metering
stations that deal with hydrocarbon liquids and utilities like demineralized water.
2. References
Reference is made in this standard to the following documents. The latest issues, amendments
and supplements to these documents shall apply unless otherwise indicated.
SABIC Engineering Standards (SES)
E02-G01 Electrical System Design Criteria (NEC or IEC)
E06-S01 Induction Motors 150 kW
Z01-G03 Metrification
American Petroleum Institute (API)
Manual of Petroleum Measurement Standards (MPMS) Chapter 8.2 Standard Practice for
Automatic Sampling of Liquid Petroleum and Petroleum Products
American National Standards Institute / American Society of Mechanical Engineer
ASME/ANSI B16.10
Face-to-Face and End-to-End Dimensions of Valves
ASME/ANSI B16.34
Valves – Flanged, Threaded, and Welding End
National Fire Protection Association (NFPA)
NFPA 70 National Electrical Code (NEC)
Process Industry Practices (PIP)
PCCCV001 Selection of Control Valves
3. General
3.1. Units of Measurement
3.1.1. SI Metric units as set forth by the International Organization for Standardization will be used
(see SES Z01-G03). Piping will be ASME/ANSI B16.34 with ASME/ANSI B16.10 dimensions
for pipe, valves, fittings, and flanges with diameters in inches, but lengths in millimeters.
3.1.2. Engineering units for all calculations and reports for custody metering stations shall be as
follows:
a. Density kg/m3
b. Flow Rate Std m3/s(1)
c. Level Percent
d. Pressure kPa
e. Temperature (C
f. Velocity m/s
g. Viscosity cP
h. Volume m3
i. Standard Conditions 15 (C and 101.325 kPa (abs)
3.1.3. Environmental Conditions
For details and descriptions refer to BEDD
3.2. Conflicts
Any conflicts between this standard, SES’s and industry standards, engineering drawings, and
contract documents shall be resolved at the discretion of the Buyer.
3.3. Buyer Exceptions
Buyer exceptions to this standard will be detailed on the purchase order.
3.4. Vendor Exceptions
Vendor exceptions to this standard to be included in the quote.
4. Meter Stations
4.1. Definition
An assemblage of equipment for the purpose of hydrocarbon liquid metering, which for the
purpose of this standard is composed of, but not limited to, the meters and associated fluid
conditioning devices, and instrumentation. A meter prover will be provided if indicated in the
project scope of work.
4.2. Custody Transfer Metering
A specialized form of metering which is the basis for selling or transferring custody of the
finished products to a customer.
4.3. Meter Run
4.3.1. Normally, this is the length of piping which incorporates the required upstream and
downstream run of the meter. For the purpose of this standard, it means a complete run of
piping which is composed of an inlet block valve, strainer, straightening element, flowmeter,
flow control valve, and an outlet block valve. This is the equipment that may be mounted on a
compact, self-contained skid, where skid mounting is preferred or justified.
4.3.2. A redundant, automated computerized metering and control system with individual flow
computers and interconnected master computers shall be used. Where a DCS or PLC based
system is available, it may be used to operate the meter station without direct operator access
to dedicated control equipment.
4.3.3. An individual flow computer shall be used for each meter run in the metering skid. In case of
failure of the redundant master computers, each flow computer shall be able to continue
metering operations on its meter run.
4.3.4. All sensitive data in the computer and flow computer that will impact the metering results shall
be protected by a password and/or a keylock combination.
4.3.5. A complete system shall be able to:
a. Regulate the flow rate for each meter run and the whole metering station.
b. Automatically conduct proving operations after lining up all the block valves involved.
c. Monitor operating parameters, annunciating and logging abnormal operating conditions.
d. Generate a hard copy of the proving and delivery tickets as well as other operating
reports.
4.3.6. A complete, operational spare meter run in each metering skid shall be provided to ensure
continuous operation.
4.4. General Guidelines
4.4.1. Packaged Unit Concept:
4.4.2. The packaged unit concept shall be used. This is to ensure that a composite system is
designed, manufactured, tested, and shipped as a complete, integrated, and working unit.
4.4.3. Total Responsibility Approach:
a. If at all possible, total responsibility for the whole metering system must be assigned to a
single vendor. This applies to all the major sections of the system such as the metering
and proving equipment together with the control instrumentation.
b. This dictates that a single vendor will undertake to put together the whole system by
using equipment of his own manufacture and/or equipment by others.
4.4.4. Overall Functional Test:
a. The complete meter station including all associated mechanical equipment,
instrumentation, control panels, cables, data logger, and computer (if used), etc., shall
undergo a functional and operational test in the vendor shop.
b. Flowmeters shall be calibrated per the manufacturer’s standard calibration procedure.
c. Meter provers (if provided) shall be calibrated by the water draw method both in the
vendor shop and in the field.
d. The automatic sample system (if provided) shall be tested by the system integrator and
also field tested to API MPMS Chapter 8.2.
e. All necessary repairs, replacements, modifications, etc., shall be completed in the vendor
shop before shipment to the field.
f. Functional test must be approved by SABIC representatives.
4.4.5. Area Classification
a. All instrumentation equipment is to be suitable for environmental conditions, See Para.
2.2. The primary elements as either the orifice meter or turbine meter shall be capable of
being installed in hazardous classification areas designated as Class I, Division 2,
Groups C and D.
b. Any secondary element such as a flow computer shall be installed in an air conditioned
general purpose environment, such as either a rack room or a control room.
4.4.6. Turbine Meter Signal Integrity
When using a turbine meter as a primary flow device, the vendor shall ensure pulse signal
integrity (security) for the distance from the primary flow element (turbine meter) to the
secondary flow element (flow computer). This may warrant a preamplifier to convert a low
voltage sinusoidal signal to a square wave pulse form that can increase the transmission
distance of the primary device to the secondary flow computer.
4.5. Design, Construction, And Installation
4.5.1. General Considerations
a. Pressure codes
All components of the meter station shall meet the applicable pressure codes for the
pipeline.
b. Welding Codes
All welding shall be in accordance with the appropriate welding codes for the plant and
service.
c. Corrosion Allowance
Proper corrosion allowance for all piping shall be provided.
d. System Configuration
(i) Hydrocarbon Liquids (Products/Raw Materials)
System shall normally consist of two meter runs arranged in series. Each meter run
shall comprise an upstream block valve, strainer, straightening element, turbine
flowmeter, down stream block valve, a meter run by-pass valve, and instrumentation
for temperature and density corrections. It shall be possible to isolate one meter run
and remove it from service without interruption of flow or any effect on operation of
the other meter run.
Flow computer with a serial interface to the DCS and a printer shall be provided in the
control building. Flow, temperature, and density signals from each meter run shall be
routed to the flow computer for corrected totalized flow calculations and periodic on
demand print out from the printer.
One of the two flow meters shall serve as a regular flow meter, whereas the other
shall serve as a check meter. The check meter shall be sent for periodic calibration to
a calibration laboratory.
Check meter run shall not be provided if the installation has a meter prover.
(ii) Other Liquids:
Custody transfer metering system for other liquids like demineralized water and wash
oil shall consist of one meter run having an orifice assembly and instrumentation for
temperature correction.
Flow and temperature signals shall be routed to the flow computer in the control room
for corrected/totalized flow calculations and periodic on demand print outs from the
printer.
4.5.2. Construction
a. Air pockets
Lines from the meter to the prover shall run such that the possibility of trapping air or
vapor is eliminated.
b. Numbers of Fittings
The number of bends and other pipe fittings should be kept to a minimum.
c. Anti-Reversal Flow Feature
Provisions to prevent flow reversal through the meter shall be provided, where required.
d. A concrete foundation, properly curbed at the periphery, shall be provided by owner. The
foundation floor shall be properly sloped towards a drain connection at the low point of
the foundation. A 3-ft. (900mm) apron around the foundation shall be provided.
e. Layout of equipment shall allow convenient access for operation, maintenance and
removal of equipment.
f. Adequate area lighting shall be provided.
4.5.3. Installation
a. Meter Prover Distance:
The distance between the meter and its prover (if provided) shall be kept as short as
practical.
b. For installations using an open drain header system, a common header shall be installed
underneath the skid to collect leakage from all bleed, vent, drain, and relief lines. It shall
be provided with a downward slope toward a common collection point. Each bleed, drain,
vent and relief line shall discharge to a drain funnel. The tip of each discharge line should
allow ample visual observation of the discharge liquid.
c. For a closed drain header system, a pressure gauge shall be installed in the bleed line of
each double block and bleed valve.
5. Meters
5.1. General Guidelines
5.1.1. Meter Selection:
a. Linearity:
The meter shall be able to operate within a linearity of plus or minus 0.25 percent or
better throughout its normal flow range.
b. Repeatability:
The meter shall be able to reproduce its output within (0.02 percent or better of meter
reading under fairly constant operating conditions.
c. Maintainability:
The meter should be easy to maintain by virtue of its construction. If possible, regular
maintenance personnel with standard tools should be able to maintain the equipment.
d. Suitability:
The meter shall be well-suited to handle the type and condition of the liquid being
measured in terms of various factors such as entrained solids, lubricity, viscosity,
corrosiveness, pressure, temperature and density.
e. Handling:
Weight and size of the meter shall be considered in terms of its impact on spacing,
transit, maintenance access, supports, foundation, etc.
5.1.2. Meter sizing:
Turbine meters shall be sized to normally operate between 10 and 80 percent of nameplate
rating.
5.2. Design
5.2.1. General Considerations:
a. Gaskets shall not obstruct free flow of liquid in the line. I.D. of gasket should be
approximately ¼ inch (6mm) larger than the I.D, of the pipe and meter flanges.
b. Nameplate material and fastening screws should be stainless steel.
c. Piping Supports shall be provided to hold the piping in place to facilitate removal of the
meter. Such supports shall not subject the meter to undue forces, strain, or vibration.
d. Isolation and Drainage Piping layout shall be such that the section in which the meter is
mounted can be isolated and drained.
5.3. Construction
5.3.1. Rotor:
The turbine meter rotor may be of the rimmed-type containing multiple “buttons” of magnetic
material for providing the proper resolution.
5.3.2. Rotor Bearings :
Where possible, the turbine meter rotor shall be supported by bearings of the “floating type”
which utilizes the flowing medium as the bearing surface. In addition, the rotor suspension
shall incorporate means for negating the effect of hydraulic shock on the meter rotor.
5.3.3. Pick-up Coils:
Two pick-up coils shall be provided for each turbine meter, one in regular service, the other a
spare or connected to a signal comparator to check the performance of the active coil.
5.3.4. Meter Flanges
The meter flanges shall incorporate dowel pins for alignment purposes and shall be of the
same size and rating as the metering pipe flanges.
5.3.5. Meter Body/Internals
The meter body flanges and internals in contact with the flowing medium shall be suitable for
the liquid being handled.
5.4. Installation
5.4.1. Position:
The meter shall be installed in a horizontal position.
5.4.2. Orientation:
The meter shall be so oriented that the possibility of water build up inside the pick-up coil
enclosure is eliminated.
5.4.3. Access:
Convenient maintenance access shall be provided for servicing the meter and its
appurtenances.
5.4.4. Provisions Against Meter Body Distortions
Provisions shall be made to eliminate meter body distortion caused by piping contraction and
expansion as well as thermal expansion of the liquid. This may be accomplished by proper
alignment, incorporating proper supports, pressure relieving devices, insulations, etc.
6. Meter Prover
6.1. General Guidelines
6.1.1. Prover Selection – shall be determined by the following factors:
a. Operation:
The prover system shall be such that a meter can be proved during normal operation on
a continuous basis without interrupting the flowrate through the meter. It may be
manually or automatically operated.
b. Frequency of Proving:
Proving of a meter shall be done as often as necessary without disrupting normal plant or
loading operations.
6.1.2. Type of Installation:
a. Permanently Installed Pipe Prover shall be used for all installations.
b. Master Prover:
A master prover to prove the main prover shall not be installed.
Note: Calibration of the main prover shall be done every five years (or earlier).
c. Choice of Prover Type:
Pipe Prover – The in-line, bi-directional pipe (sphere or piston) prover is preferred over
any other type of prover.
d. Accessories:
(i) Displacers – For actuating the prover detector switches, a displacer shall exhibit the
following characteristics:
(ii) Optimum resiliency.
(iii) Excellent resistance against wear.
(iv) Compatibility with the liquid being handled to eliminate deterioration caused by
chemical reaction.
6.2. Design
6.2.1. General Considerations:
a. Resolution
The prover shall have a minimum resolution of 1 part in 10,000 for any one-way run.
b. Capacity
The prover shall be sized to handle the normal maximum anticipated operating flowrate
of the largest meter in a multiple meter run station.
c. Volume:
The prover volume between the two detector switches shall be equal to or more than 0.5
percent of the maximum flow rate per hour of the largest meter to be proved or be
represented by at least 10,000 generated meter pulses.
d. I.D. Tolerance:
The difference between the maximum and minimum inside diameter of the finished pipe
and fittings within the calibrated section shall not exceed 0.5% of the nominal pipe I.D.
for bi-directional piston provers of 18 inch diameter or less or 0.75% of the nominal pipe
I.D. for bi-directional sphere provers.
e. Configuration:
The prover section can either be a straight piece of pipe, or it may be contoured or folded
pipe for reasons of space limitation or portability.
f. Pipe Selection:
Pipe shall be selected for roundness and smoothness and be of sufficient continuous
lengths so as to minimize the number of pipe joints. Any pipe welds must be ground
smooth to the pipe I.D.
g. Displacer Velocity:
The displacer velocity in the calibrated section shall never be below 0.152 m/s. Maximum
velocity shall not exceed 2.44 m/s for provers with a nominal I.D. of up to 24 inch or 1.83
m/s for provers with an I.D. exceeding 24 inches.
h. Water Draw Connections:
Two pipe connections, each with size no smaller than 2-inch shall be provided near the inlet
and outlet of the diverter valve to facilitate water draw calibration.
6.3. Construction
6.3.1. Inlet/Outlet:
The inlet and outlet lines, including valves and connections to the prover should be sufficiently
large to minimize the restriction in flowrate through any meter when flow is directed through
the prover.
6.3.2. Inlet/Outlet Connections:
The inlet/outlet connections to the prover shall be located on the bottom side to prevent
accumulation of dirt and other foreign materials.
6.3.3. Pre-run length:
To ensure that the diverter valve has seated and is properly sealed and flow stabilized before
the displacer actuates the detector switch, sufficient length of run shall be provided.
6.3.4. Launch/Separator Tee Slope:
To ensure proper movement of the displacer prover during periods of low flow, the tees shall
have sufficient downward slope.
6.3.5. Launch/Separator Tee Size:
a. Tee shall be at least one pipe size larger than the size of the displacer.
(i) Liquid velocity shall not exceed 1.524 m/s.
(ii) Smooth flow transition fittings shall be used on both ends of the tee.
(iii) Means shall be provided to prevent the displacer from leaving the tee assembly
during proving.
6.3.6. Internal Coating:
A suitable internal coating of the prover section which will provide a hard, smooth, and lasting
finish shall be provided. Air-dried epoxy, where used, shall have a maximum thickness of 5
mils with holiday free reading checked by wet film test.
6.3.7. Water Draw Connections:
Connections shall be provided to facilitate water draw calibration.
6.3.8. Insulation:
When installed above ground, the prover and all piping between the meters and prover shall
be thermally insulated for better temperature stabilization.
6.3.9. Vent Valves:
Shall be provided, preferably at the prover launchers, to vent any trapped gas in the prover.
6.3.10.
Drain Valves:
Shall be provided to drain the liquid in the prover during servicing.
6.3.11.
Isolation valves:
Positive shut-off valves shall be provided for isolating the prover from the metered stream
when not in use.
6.3.12.
Lifting Lugs:
Should be provided for skid-mounted units as a whole and also for components weighing in
excess of 23 kg and where it cannot be handled properly by a sling.
6.4. Installation
6.4.1. Location:
The prover shall be installed downstream of adequate straining or filtering equipment.
6.4.2. Pipe Alignment:
Care must be exercised to ensure proper alignment and concentricity of pipe joints in as neat
a manner as practical. All flanged joints in the prover and meter run are to be pinned or
doweled.
7. Instrumentation
7.1. General Guidelines
7.1.1. Common:
a. Type
Instruments shall be of the solid state, electronic type design to suit the particular needs
of custody transfer metering.
b. Components:
Instruments shall be constructed from high quality, state of the art components.
c. Power Supply:
Instruments shall not require special stabilized power supply for successful operation.
d. Noise Immunity:
Instruments shall not be susceptible to nearby sources of spurious signals to protect the
integrity of meter readings.
e. Enclosures:
Shall meet the requirements of the electrical area classification of their locations per
NEC.
f. Access:
Convenient and ample access for operation and maintenance purposes shall be
provided.
g. Installation:
Manufacturer’s prescribed procedures in installing the instruments should be followed.
7.1.2. Field-Mounted Instruments:
a. Electronic Components
Shall be able to operate satisfactorily under the environmental conditions described in
paragraph 3.2 of this standard.
NOTE: It should be noted that under possible extreme conditions of direct sunlight, nonventilation,
and heat radiated from nearby sources, the dead-air temperature inside an
instrument case may reach 74 deg C. Adding to this temperature the heat dissipated (if
any) by internal components, the resulting internal temperature in the instrument
enclosure may go as high as 85 deg C.
b. Sunshades:
Use of individual sunshades to lower the operating temperature of the instruments
should be avoided.
c. Metallurgy:
Instruments shall incorporate parts of correct metallurgy which are compatible with the
liquid being handled as well as the gaseous environment where the instruments are
installed.
7.1.3. Panel-Mounted (Control Room) Instruments
a. Environment:
Instruments shall normally be installed in an air conditioned control building or enclosure.
b. Temperature rating
Instruments shall be capable of normal operation even during extended periods of air
conditioning equipment failure. Instruments are expected to function in an ambient
temperature of 50(C maximum plus the temperature rise resulting from the heat
contribution of all components in the instrument case.
c. Plug-In Components:
Instruments should incorporate plug-in components for ease of maintenance.
d. Access:
Instruments with front access maintenance and servicing features are preferred.
e. Readout:
Instruments shall provide a visual readout device with the meter and its transmission
system.
7.2. Design, Construction and Installation
7.2.1. Field-Mounted
a. Pulse Generator
For turbine meters, a system that directly transforms the mechanical motion of the rotor
into electrical energy through magnetic induction shall be provided.
b. Signal Preamplifier :
If required, shall be mounted directly on the meter (at the generation source) to reduce
the possibility of spurious signal pick-up at low signal levels.
c. Power Detection Switches:
Shall have a maximum allowable linear accuracy of (0.0075 inch or better. They shall
have no readily accessible external adjustments to eliminate the possibility of changing
the calibrated volume of the prover by unauthorized persons.
7.2.2. Panel Mounted
a. Flow Totalizers:
Shall be pulse driven, with a 6 (or more) digit, nonresettable, electromechanical or all
electronic digital display. The minimum resolution of the displayed total shall be plus or
minus one whole basic unit. The basic unit is normally metric tons.
(i) Meter Factor Selection – the totalizers shall incorporate a means of setting a 5-digit
meter factor which will scale the input pulses from the flowrates so that each count in
the meter is equal to the desired unit of measure. The meter factor switches shall not
be located on the front panel of the totalizer.
(ii) External Standby Power – In case of power failure or instrument fault, the totalized
quantity indication shall not be lost. Suitable external battery power shall be provided
when using an all electronic digital display.
(iii) Calibration – Built-in oscillator for calibration purposes, switches input ranges, and
output conversion for current or voltage output shall be provided, the controls of which
shall not be located on the front of the panel.
(iv) All flow totalization will be carried out by a flow computer or mainframe computer.
Temperature and density corrections will to be applied to flow measurements.
Correction signals will be obtained from transmitters/transducers installed
downstream of the flowmeters. All totalization/display will be in engineering units.
b. Flowrate Indicators
Shall indicate the actual flowrates for each meter run in actual engineering units or
percent of maximum flowrate on a 0-100 percent linear scale. They shall provide the
following:
(i) Accuracy of indication to be equal or better than plus or minus 1.0 percent of full
scale.
(ii) The range of the flowrate indicator should be approximately 1.2 times the maximum
linear flowrate of the flowmeter.
(iii) Meter span and zero calibration adjustments shall be so located where they can be
accessed by authorized service personnel only.
c. Signal Transmission:
Shall be designed to protect the integrity of instrument signals from electrical noise
brought about by electromagnetic induction, electrostatic or capacitive coupling, and
electrical conduction. The following basic precautions shall be taken in transmission
system design:
(i) Shielded signal cable shall be used. The meter manufacturer’s advice must sought
and followed in selecting the proper cable to be used but as a minimum this shall be
twisted pair, stranded wire, 1 mm² to 1.5 mm², and braided over with an aluminum
mylar shield and PVC insulating cover.
(ii) Grounding of the cable shield shall be done at the readout end only, to prevent
ground loop effect. The grounding of parallel readout devices and other panelmounted
instruments should follow the manufacturer’s recommendations and be
grounded at one common point.
(iii) Conduit for transmission cables shall be made of rigid galvanized steel to provide
maximum shielding against unwanted electromagnetic radiation. Non ferrous conduits
shall not be utilized since they do not provide any reduction in magnetic noise.
Conduits shall be properly grounded.
(iv) All signals transmitted over a distance of more than 50 feet shall be balanced with
respect to signal ground.
(v) Control / Measurement and Power Cables shall not be run in the same conduit or
raceway.
(vi) Each turbine meter signal cable shall solely occupy its own conduit.
d. Interlock Circuit
Shall be provided to prevent the operation of the prover diverter valve when these
conditions exist:
(i) When all the block valves involved in a particular meter proving run have not been set
properly, including diverter valve.
(ii) When the flowrate passing through the meter being proved exceeds its normal
maximum rated flowrate.
e. Emergency Shutdown (ESD) System
The ESD system shall effectively control the shutdown operation of the flow control
valves in the proper sequence in the event of:
(i) Actuation of the emergency shutdown push-button.
(ii) Failure of main power supply.
8. Electrical
8.1. General Guidelines
8.1.1. Common
a. All electrical installations shall comply with the latest issues of the NEC and SESs E02G01
and
E06-S01.
b. Enclosures shall meet the requirements of the electrical classification of the area.
c. Installation of all equipment should be installed in accordance with the manufacturer’s
recommendation.
d. All electrical controls and components should be placed in convenient locations for
operation and maintenance.
e. Lifting Lugs shall be provided for equipment weighing in excess of 23 kg and where it
cannot be handled properly by a sling.
8.1.2. Field Mounted Equipment
Shall be capable of satisfactory operation under the environmental conditions described in
paragraph 3.2 of this standard. For other factors contributing towards a higher temperature
operating condition, refer to paragraph 7.1.2.a of this standard.
8.1.3. Design, Construction, And Installation
8.1.4. Equipment and Accessories
a. Conduit and Fittings in corrosive atmospheres should be provided with the proper
material or coating.
b. Breathers/Drains shall be NEC approved and will be incorporated in conduit system
together with suitable seals to minimize the problems associated with moisture build-up.
(i) Conduit shall drain away from electric equipment and terminal boxes.
(ii) Conduit and Terminal Boxes shall be self-draining at all low points.
c. Terminal/Junction Boxes on skid-mounted or packaged units will be mounted at an
accessible location on the edge of the skid.
(i) Conduit Connections will be bottom entrance only.
(ii) High Barrier Terminal Blocks with screw type terminals will be provided.
(iii) Terminal Identifications shall be effected by use of heat-shrinkable, permanently
embossed, slip-on type wire markers.
(iv) Terminals shall be tagged in accordance with the associated connection diagram.
(v) Spare Conduit Holes will be plugged and epoxy-coated.
d. Electric Motors for hydraulic applications shall comply with the provisions of SES E06S01.
e.
Pushbuttons and Manual Stations installed in corrosive atmospheres should have
operator shaft assemblies made of corrosion resistant materials to prevent the shaft from
binding. Mounting accessories such as screws and hinges shall be stainless steel.
f. Small Electrical Apparatus will be installed, wherever possible, within a weather
protecting enclosure.
8.1.5. Electrical Supply Systems
Metering stations shall have their Power System designed in accordance with SABIC practice
as specified in SES E02-G01.
a. Typical voltage supplies to be used are the following:
(i.) 480 volts, 3 phase, 60 Hz – power for motor operated valves, central hydraulic pump
units, motors, etc.
(ii.) 120 volts, single phase, 60 Hz – power for field and panel mounted instruments,
lighting, small motors and certain motorized valves, solenoids, DC power units for
solid state logic circuits, annunciators, etc.
(iii.)
125 volts, DC power for emergency lighting and equipment.
(iv.)
8 or 125 volts, DC power for emergency shutdown circuits.
b. Electrical Supply for Panel-Mounted Instrumentation
Voltage supply shall be 230 volts, single phase, 60 Hz. In cases where a different voltage requirement is
necessary, integral or separate power packs, constant voltage transformers, etc. shall be provided.
9. Valves
9.1. General Guidelines
Common guidelines that apply in the selection of manually and remotely operated valves are
the following:
9.1.1. Valves shall comply with the pressure/temperature rating of the pipeline.
9.1.2. Valves that offer simplicity in construction are preferred but an industry proven record of good
performance in custody metering manifolds is required.
9.1.3. Bypass valves around a meter or battery of meters shall be provided with a positive shut-off
device equipped with a telltale bleed or sight glass.
9.1.4. All valves, especially spring-loaded or self-closing types shall be completely air tight so as not
to leak or admit air into the pipeline when subjected to hydraulic hammering or vacuum
conditions.
9.1.5. Valves shall be provided with convenient access and adequate space for ease of inspection,
removal and maintenance.
9.1.6. All valves weighing in excess of 23 kg and where they cannot be handled properly by a sling,
should be provided with lifting lugs for ease of handling.
9.2. Design and Installation
9.2.1. Control Valves:
For meter run and prover services, control valves shall:
a. Maintain the minimum back pressure required downstream of the meter to prevent
flashing.
b. Balance the pressure drops in a multiple meter system when one of the meters is
switched to the prover.
c. Control the flowrate through a meter during blending operations.
d. Control loading rates through a royalty meter during normal operation by compensating
for changes in system pressure.
e. Overcome the full pumping head of the system during closing or opening.
f. For controlling intermittent flow, valves shall be of the fast acting, shock free type so as
to avoid damaging the metering equipment and accuracy of measurement. Use of an
axial-flow type valve should be considered.
g. For selection of control valves refer to PIP PCCCV001.
9.2.2. Block Valves:
a. General Considerations
(i.) Valves that can bypass liquid around meters or prover, or affect metering and proving
results shall be bubble-tight and provide tight shutoff on low differential pressure
conditions.
(ii.) A double block and bleed type valve with soft seats shall be used where valve
leakage can affect the integrity of metering or proving.
b. Manually Operated Valves:
(i.) Should generally be limited to smaller sizes only, or where effort on the part of the
field operator will not be too excessive and rapid closing or opening is not mandatory.
(ii.) Should be provided with a vertical handwheel (with horizontal shaft) where the size of
the valve prevents convenient operation of a horizontal handwheel.
c. Motor Operated Valves:
(i.) Shall be capable of rapid and smooth closing and opening throughout the travel
range.
(ii.) Should incorporate emergency manual operation capability for use in the event of
power outage, actuator failure or maintenance.
(iii.)
Each gate valve stem should be covered with a transparent plastic cylinder
for valve position indication and weather protection.
9.2.3. Diverter Valves:
Diverter valves for reversing the flow in the meter prover shall provide a positive, bubble tight
shut-off during proving. It shall incorporate the following:
a. A pressure gauge and alarm for monitoring its pressure sealing before proceeding with
the proving.
b. A valve position indicator and interlock for monitoring and ensuring that the valve seating
is complete before the displacer actuates the first detector to make sure that no flow is
bypassed during proving.
9.2.4. Pressure Relief Valves:
Should be installed for the control of thermal expansion and contraction of the liquid in the
prover and meter runs while they are completely isolated from the main stream. They shall not
discharge directly to the atmosphere but through a properly sized discharge line to a common
blowdown system or be installed around a block valve.
9.2.5. Check Valves
Should be used in preventing a reversal of flow through the meters. They shall not be installed
on the meter run skid.
10. Fluid Conditioning Devices (F.C.)
10.1. General Guidelines:
Common guidelines that apply to all fluid conditioning devices are:
10.1.1. They shall comply with the pressure/temperature rating of the pipeline.
10.1.2. A device that offers a less complicated design but performs or delivers the desired result
should be considered.
10.1.3. They shall be so located to provide convenient access for ease of inspection, removal and
maintenance.
10.1.4. No bypass valves or lines around these devices shall be allowed.
10.1.5. For single meter installation, a dual arrangement of F.C. devices, with the exception of the
straightening element, may be considered.
10.1.6. For multiple meter installations, dual arrangements of F.C. devices shall not be provided.
10.1.7. All F.C. devices in excess of 23 kg and where it cannot be properly handled by a sling
should be provided with lifting lugs for ease of handling.
10.1.8. All wetted part materials shall be compatible with the liquid being handled.
10.2. Design and Installation
10.2.1. Strainers
Shall be used in all meter runs regardless of the type and condition of the liquid being
metered to protect the meters against intrusion of pipe scales, welding spatters and other
foreign materials.
a. General considerations are low pressure drop, low maintenance and ease of operation.
b. Accessories
(i) A bellows type differential pressure indicator/switch combination shall be provided.
(ii) A differential pressure gauge indicator shall not be used.
c. Construction
(i) The strainer shall be supplied with a suitable element of a mesh size that will not
cause an unacceptable pressure drop while providing adequate protection to the
meter. The element shall either be of perforated metal basket or double mesh (1coarse,
1-fine)
construction.
(ii)
Vent,
drain, and upstream/downstream differential pressure connections shall be
provided.
d. Installation
Strainers shall be installed on the meter run skid, directly upstream of the meter tube and
should be accessible for removal.
10.2.2. Straightening Elements
Shall be installed to eliminate liquid swirls and cross currents set up by pipe fittings and valves
preceding turbine meters.
a. General Considerations
(i) Flange type Straightening Element shall be used in a 3-section meter tube and is
recommended for pipe sizes below 20 inch.
(ii) Line type Straightening Element shall be used in a 2-section meter tube and is
recommended for pipe sizes 20 inch and above.
b. Construction
(i) Length shall be at least 3 pipe diameters or 10 times the diameter of the tubing length
used in the assembly, whichever is longer.
(ii) Elements shall be sufficiently rugged to resist distortion or movement at high flow
rates.
(iii) Elements shall be manufactured from identical thin wall tubing of any cross-sectional
shape, or light gauge metal vanes suitably smoothed on the leading and trailing
edges.
(iv) In cross-section, the design shall be as nearly uniform and symmetrical as possible.
(v) No less than 4 tubes or vanes shall be employed.
(vi) Meter tube flanges shall be doweled or notch-marked to ensure proper line-up with
the turbine meter flanges.
c. Installation
(i) They shall be aligned parallel to the pipe axis.
(ii) Gaskets shall be internally aligned and shall not protrude inside the pipe.
(iii) There shall be no other intervening devices between the straightening element and
meter.
(iv) They are to be fastened securely in place to prevent being dislodged toward the
meter.
11. Documentation
11.1. General
11.1.1. Meter and meter prover calibrations shall be documented and shall be sent to SABIC in
advance of product delivery for evaluation and record.
11.1.2. Drawings, schematics, flow computer configuration sheets and operating manuals, and
product literature adequate to facilitate proper operation and maintenance of the stations
and components shall be provided in the number stipulated in project specifications.
12. Testing and Inspection
12.1. General
12.1.1. A complete metering system shall undergo a functional and operational flow test in the
Vendor’s shop. Where retrofit equipment is involved, it shall be tested using a simulator.
12.1.2. Flow meters shall be calibrated per the Manufacturer’s standard calibration procedure.
12.1.3. Automatic sampling system for products shall meet the field test requirements as specified
in API MPMS Chapter 8.2.
12.1.4. Meter provers may be calibrated by either the water draw or master meter method in the
Vendor’s shop. Final calibration in the field shall be per the water draw method.
12.1.5. All necessary repairs, replacements and modifications to hardware, reports and software
programs, etc., shall be completed in the Vendor’s shop before shipment to the field.
Functional tests shall be witnessed and approved by (SABIC) representatives