1. SCOPE
1.1 Plant Piping
1.2
Other Piping
2. REFERENCES
3. DEFINITION
4. GENERAL REQUIREMENTS ……….
IDENTIFICATION OF MATERIAL
5.1 Positive Material
Identification
5.2
Color Coding …………………………….
5.3 ASME B31.1 Piping
6. MARKING AND STORAGE
6.1 Marking
……………………………………
6.2 Storage
6.3
Stacking
6.4 Components
……………………………..
6.5 Protection
6.6 Cleaned Piping
6.7
Austenitic Stainless Steel ……………
7. HANDLING
7.1 Damage Prevention
7.2
Lined and Coated Piping …………….
7.3 Painted Piping
8. PIPE FIT-UP AND TOLERANCES
8.1
Accuracy ………………………………….
8.2 Dimensional
Tolerance
8.3 Bending
Tolerance
8.4 Flange Misalignment
………………….
8.5 Fit-up
9. FIELD FABRICATION
9.1 Welding
……………………………………
9.2 Pipe Bending
9.3 Welding
9.4
Integrally Reinforced Branch Outlet
Fittings …………………………………….10. ERECTION
10.1 Erection Drawings
10.2 Joints ……………………………………….10.3 Bolting
10.4 Orifice Flanges
10.5 Welded Pipe
……………………………..
10.6 Socketweld Joints
10.7 Threaded Joints
10.8 Compressor and Equipment Piping Field Welds ……………………………….10.9
Valves
10.10 Expansion Joints
10.11 Strainers
…………………………………..
10.12 Threaded Connections
10.13 Fabricator-Installed Plugs
10.14 Drawings
………………………………….
11. EXAMINATION, INSPECTION AND
TESTING
11.1 General
11.2 Inspection
…………………………………
11.3 Radiography
11.4 Branch Connection Examination
11.5 Magnetic Particle Examination ……..11.6
Liquid Penetrant Examination
11.7 Hardness Tests
11.8 Reports……………………………………..12. CLEANING
12.1 Special
cleaning
12.2 Erecting Cleaned piping ………………12.3 Recleaning
12.4 Spool
Inspection
12.5 Flushing…………………………………….12.6 Chemical Cleaning
12.7 Component Protection
13. BURIED INSTALLATION………………….13.1 Coating
13.2 Burial
14. PRESSURE TESTING …………………….
1. Scope
1.1 Plant Piping
This standard prescribes requirements for the field fabrication and erection of metallic piping inside plants,
that is engineered and designed to ASME B31.1 and ASME B31.3. This standard prescribes additional
requirements of a supplemental nature, and does not abrogate the B31 codes in any way.
1.2 Other Piping
This standard applies to ASME B31.3 piping that is attached to pipelines.
2. References
All referenced specifications, standards, codes, forms, drawings and similar material, including all
revisions, addenda and supplements, shall be of the latest issue unless stated otherwise. When a project
is in effect, the version of engineering and design codes, specifically ASME B31 codes, shall govern, as
specified in the contract for that project.
SABIC Engineering Standards (SES)
P01 E15 Pressure Testing and Lay up Procedures
P28 G01 Piping Joints
P27 G01 Selection of Bolts
W05 F02 Welding Requirements for On-Plot Piping
E29 C01 Cathodic Protection
W02 F01 Welding-Safe Practices
Q01 T07 Pressure Vessels Materials Inspection Program
W01 F01 Welding and Inspection -Performance Standards
P01 E27 Cleaning Requirements of Piping Systems
P01 E08 Expansion Joints and Cold Spring
P14 T01 Inspection Requirements of In-service Pipeline
P13 C01 Construction, Installation and Backfilling Procedures
P12 S04 Color Coding Criterion
Industry Codes and Standards
American Society of Mechanical Engineers (ASME)
B31.1 Power Piping
B31.3 Process Piping
PFI ES3 Fabrication Tolerances
PFI ES24 Pipe Bending tolerances
3. Definition
PMI. Positive Material Identification
PWHT. Post Weld Heat Treat
4. General Requirements
4.1 Materials Identification
4.2 Marking Handling and Storage
4.3 Fit-up and Fabrication
4.4 Erection
4.5 Examination, Inspection and Testing
5. Identification of Material
5.1 Positive Material Identification
5.1.1 Marking
All pipe and fittings shall have the material specification and grade stamped, stenciled, or otherwise
marked.
5.1.2 Alloy Testing
Materials must not get mixed up at any time, from manufacturing to installation. Alloy testing is prescribed
in SES Q01-T07. Material should be verified both at the vendor, and the site.
5.2 Color Coding
Once the material has been verified, a color code is applied. SES P12-S04 prescribes the marking
methods that will not allow the marking to be degraded.
5.3 ASME B31.1 Piping
Materials for ASME B31.1 piping have special documentation, and must be carefully segregated.
6. Marking and Storage
6.1 Marking
6.1.1 Marking Materials
Any marking of austenitic stainless steels and nonferrous alloys shall be done in one of two ways. Either
use an aluminum tag strapped or wired to the fitting or valve or use a paint or ink which contains no harmful
metal, metal salts or elements. These chemicals include zinc, lead, copper, chlorides, sulfur or any other
ingredient which upon heating causes corrosive attack on the base metal. The erection contractor shall
submit a list of his proposed marking paints or inks to SABIC for review.
6.1.2 Pipespool Marking
a. The field shall mark all pipespools with the pipespool number. Stencil or paint the spool number
on each pipespool with waterproof paint in figures not less than 19 mm high. Spools which are too
small to have a painted spool number shall be marked by painting or by die-stamping the spool
number on an aluminum tag which shall be securely attached to the spool with 16 gauge stainless
steel wire.
b.
In addition to paint-marking, the spool number must be die-stamped or electro-etched on the
circumferential surface of at least one flange, or on the pipe about 300 mm from a buttweld end.
6.2 Storage
Pipe shall not be stored directly on the ground. Pipe shall be placed on blocking.
6.3 Stacking
Stacking shall be done in such a way to avoid damage to pipes or coatings.
6.4 Components
Fittings and valves shall be stored in shipping crates or on racks.
6.5 Protection
End protectors on flanges, weld bevels, threads, and socket ends shall be firmly attached. End protectors
for flanges shall be affixed with at least two bolts.
6.6 Cleaned Piping
Piping that has been specially cleaned must be stored carefully, preferably inside.
6.7 Austenitic Stainless Steel
Austenitic stainless steel may be subject to chloride attack in the Jubail area, and inside storage is
preferred.
7. Handling
7.1 Damage Prevention
All material shall be handled with care during fabrication and installation to prevent damage.
7.2 Lined and Coated Piping
Lined and coated pipes and fittings shall be lifted with wide fabric or rubber-covered slings and padding
shall be used to prevent damage to lining or coating.
7.3 Painted Piping
Piping may arrive pre-painted, or primed. Care must be taken to minimize damage to these coatings.
8. Pipe Fit-Up and Tolerances
8.1 Accuracy
The field is responsible for the accuracy of field fabrication. Piping Fabrication Institute Standard ES-3,
Fabricating Tolerances, shall be the basis of pipespool tolerances.
8.2 Dimensional Tolerance
The tolerance for axial dimensions, face-to-face, center-to-face and location of attachments shall be ±
3 mm maximum.
8.3 Bending Tolerance
Flattening of bends, measured as the difference between the largest and the smallest outside diameter at
any cross section, shall not exceed 5 percent of the nominal diameter of the pipe. Flattening of bends at
weld ends shall not exceed 3 percent of the nominal pipe diameter.
8.4 Flange Misalignment
In addition to the requirements of PFI ES-3, for piping over NPS 3 connected to machinery, the flange
separation shall not exceed the gasket thickness plus 1.6 mm, unless piping stress analysis shows that
loads and moments are within the manufacturer’s limits for the machinery/equipment nozzle:
8.5 Fit-up
During design, the final dimensions may not be available, for certain items, or the nature of the design may
dictate allowances for fit-up in the field. When a spool is marked as a fit-up, there is 150 mm of additional
material to allow for the fit-up.
9. Field Fabrication
9.1 Welding
9.1.1 Welding and Welder Qualifications
All welding procedures, welders, and welding operators shall be qualified in accordance with
SES W02 F01.
9.1.2 Taper Boring
The inside contour of all components with 1.6 mm mismatch, excluding valves, shall not follow its natural
geometry, but shall be taper-bored or contour-bored at a slope not exceeding 30 degrees until the
mismatch is within the tolerances specified. However, this trimming shall not result in a piping component
wall thickness less than minimum design thickness. For full information, see SES P28-G01.
9.1.3 Preheat
The temperature to be used shall be in accordance with the controlling codes. Preheat temperatures shall
be measured by means of temperature indicating crayons, contact pyrometers, or thermocouples.
9.1.4 Stress Relieving
a. The Erection Drawing and the Line List indicate the need for PWHT (post-weld heat treatment) of
welds in prefabricated pipe spools. Attachments such as pipe shoes, dummy extensions and legs, and
wear pads shall be welded to the pipe spools before stress relieving.
b. Special care shall be taken during furnace postweld heat treatment to prevent scratches or
damage to flange gasket surfaces. Flanges with a 3 Ra or smoother finish require a light-gage metal
shield for the gasket face held on by wire or bolts during the heat treatment. After heat treatment
remove any heat scale from the gasket face by buffing. Threaded connections shall be protected from
damage by heat. Pads and other attachments shall be welded to the lines before heat treatment.
9.1.5 Quenching
No water shall be applied to stainless steel piping except as in quenching from solution annealing
temperatures using approved procedures.
9.2 Pipe Bending
9.2.1 Bending
Pipe bending shall be in accordance with the applicable code. Tolerances shall be in accordance with Pipe
Fabrication Institute Standard ES24, 1975, Pipe Bending Tolerances. The minimum centerline radius of hot
and cold bent carbon steel and alloy pipe is six times the nominal diameter of the pipe unless specified
otherwise on the piping drawings. Pipe bending shall not thin the wall thickness below the minimum
required for design temperature, design pressure, and corrosion allowance as listed in the material class.
9.2.2 Flattening
Flattening of the bend shall not exceed the limitations of ASME B31.3, or ASME B31.1 when applicable, for
internal and external pressures. A smooth bend contour must be maintained. Creased or corrugated bends
are not permitted. Do not use coiled A53, or A106, Grade B pipe.
9.2.3 Hot Bending
a. Hot bending of ferritic piping materials shall be done within a temperature range consistent with
material characteristics, end use, or heat treatment as required by ASME B31.3 or ASME B31.1 when
applicable. Quenching ferritic alloy pipe with a cooling liquid is not permitted.
b. Austenitic stainless steel piping is to be bent cold unless approval for hot bending is obtained
from SABIC. Details of hot bending procedures must be reviewed by SABIC before approval can be
given.
c. Spot heating of austenitic stainless steels for purposes of alignment or straightening requires the
use of temperature-indicating crayons or some other suitable control during the application of heat, to
ensure temperatures never exceed 425°C. This is to avoid sensitization of the material. It is preferred
that the use of heat for these alignment procedures will be less than 15 minutes.
9.2.4 Seams
a. Seams in welded pipe shall be on the inside of all bends.
b. Buttweld girth joints shall not be located in the curved section of hot or cold bent pipe. Water
quenching is not permitted.
9.3 Welding
9.3.1 Reinforcement
a. The type of reinforcement is tabulated in the individual Piping Material Class and the erection
Drawing.
b. Where branch reinforcement is required for thermal or mechanical stress, the reinforcement
shall be shown on piping isometric and orthographic drawings.
9.3.2 Stub-ins
Where field welds occur at stub-ins to random pipe headers, the spool fabricator is required to supply the
spool end contoured and ready for welding. If reinforcement is required, the reinforcement shall be
included with the shop spool.
9.3.3 Reinforcing Pads
a. Pads for random pipe headers shall be shipped loose, wired or taped to the spool, and
separately identified with the spool number.
b. Material for pad reinforcement shall be the same composition as the base material of the pipe.
Where services require impact tested pipe then the pad reinforcement material must also be impact
tested.
c. Each pad or piece, if the pad is made in more than one piece, shall have a 6 mm vent hole
provided in the pad.
d. Examination and any necessary repairs of the completed pressure weld shall be made before
adding reinforcing pads.
9.4 Integrally Reinforced Branch Outlet Fittings
Particular attention shall be given to ensure a root gap at branch connection welds at all integrally
reinforced outlet fittings as recommended by the manufacturers’ installation procedures. This is necessary
to ensure that adequate weld reinforcement is available at the joint between the fitting and the pipe.
10. Erection
10.1 Erection Drawings
The isometric drawings show the general arrangement, and indicate all of the requirements for erection,
including heat treatment, painting, and cleaning.
10.2 Joints
See SES P28-G01 for piping joints and limitations.
10.3 Bolting
10.3.1 Bolts
Bolts shall be visually checked prior to use for any physical damage to shanks or threads which would
interfere with bolt assembly or performance. All bolts are stamped on the ends with the material grade.
The material should also be checked against the material list, before assembly.
10.3.2 Tightening Sequence
Bolts shall be tightened in a sequence to produce even compression and ensure uniform bolt loads.
10.3.3 Bolt Torque
A starting bolt torque table is found in SES P27-G01. The relationship between bolt torque and the strain
in the bolt is subject to many variables. Various lubricants, and friction factors are also included.
Experience levels out the variables.
10.3.4 Torque Wrenches
The manufacturer’s instructions shall be followed for the operation and maintenance of all torque
wrenches used to perform tightening procedure. Calibrate torque wrenches daily. Implement a daily
calibration log for torque wrenches prior to daily use.
10.3.5 Bolt Lubricant
Different lubricants have different friction factors which must be taken into account.
10.3.6 Stud Tensioners
Large bolts, and high pressure ratings, especially in steam and hydrogen service in Class 900 and higher,
may warrant the use of pneumatic or hydraulic stud tensioners. When stud tensioners are used, the
manufacturers procedures must be followed.
10.4 Orifice Flanges
The inside surface of welded joints at orifice flanges shall be ground or machined smooth.
10.5 Welded Pipe
When welded pipe is joined, the weld seams shall be staggered and located so that they will not intersect
openings and external attachments.
10.6 Socketweld Joints
The weld dimensions and gap for socketwelding piping joints shall not be less than the minimum
dimensions shown in ASME B31.3, or ASME B31.1, when applicable.
10.7 Threaded Joints
Threaded couplings or nipples that are welded to pipespools must be checked for fit and roundness after
welding or heat treatment by using a thread gage. Unacceptable threads shall be chased with a tap or die
and cleaned of cutting oil with a suitable solvent.
10.8 Compressor and Equipment Piping – Field Welds
Special control is required for the root pass of all field welds in compressor suction piping or other
equipment piping fabricated under the cleanliness requirements of SES W05-F02. The root pass shall
have no more than 3 mm internal reinforcement.
10.9 Valves
10.9.1 General
All valves requiring frequent operation, and located more than 2 m above the operating level, require
extension stems or chain wheels. Valves equipped with chain wheels shall have the stems arranged so that
chains do not fall on equipment. Hooks shall be provided to hold chains clear of operating areas. Chain
wheels are shown on the piping drawings.
10.9.2 Chain Operators
a. Chain operators on NPS 6 valves and larger shall be provided with impact devices. Do not use
chain wheel operators on threaded valves or globe valves that are NPS 1
/2 or less.
b.
1
Install valves so that the stems are not below a horizontal position. Orient all valves so that the
handwheels do not obstruct passageways.
c.
Impact-type handwheels or handles may be installed on extended stems if the stem is
independently and adequately supported or guided. The use of universal joints is not allowed.
d. The assembly drawings may show a particular orientation of valve topworks.
10.9.3 Soft-Seal Valves
a. Lines requiring soft-seal valves shall be thoroughly cleaned, flushed, and drained before the
soft-seal valves are installed. The hydrotest for these lines may be conducted at this time, and the
soft-seal valves installed after hydrotest.
b. Soft-sealed ball valves with buttwelding ends, socketwelding ends, or threaded ends requiring
seal welds, shall have the internals removed, including any soft-seal material, prior to welding. Valve
internals shall be reinstalled in the valve from which they were removed, to minimize problems.
Package and seal the internals while removed from the valve. Valves that have been purchased with
factory welded extensions or “pups”, are exempt from dissassembly.
c. Do not replace the internals until the valve has cooled to ambient temperature.
10.9.4 Butterfly Valves
a. Mating Piping
Because the disk of the butterfly valve swings into the mating flange, and piping, the interior of mating
pipe and flanges must be checked, and found free of any obstructions such as weld icicles that might
interfere with the disk, before installing the valves.
b. Resilient Seated Butterfly Valves
Before installation, make sure that the mating flanges valves are sufficiently separated for ease of
installation. Do not wedge or force the valve into position, as this could damage the resilient surfaces.
c.
Installation
Butterfly valves with resilient seats shall be installed with the disk set in the open position prior to
tightening the bolts. After the bolts are tight, check operation of the valve through a complete open
and closed cycle to ensure that the disk has not been jammed during the installation.
d. Other butterfly valves
Manufacturers recommendations shall be followed when installing other types of butterfly valves.
10.10 Expansion Joints
See SES P01-E08 for special instructions on expansion joints. The joints are shipped to the jobsite locked
in a preset position with shipping bars that are identified by a contrasting color and are tagged with
instructions to remove the shipping bars before start-up. The joints are also marked with a flow direction
arrow and a diagram of the offset. Check the piping isometrics or mechanical drawings for correct
orientation. The piping shall be fitted to the expansion joint in its locked-in position. Under no
circumstances shall the shipping bars be altered or removed to favor fit-up of the piping. Make a final
check after the line has been tested and prior to start-up to assure that the shipping bars have been
removed and the preset is installed in accordance with the drawings or specification.
10.11 Strainers
Strainers shall be installed ahead of all pumps and compressors before pipeline flushing. They shall be
located between the suction block valve and the equipment.
10.12 Threaded Connections
10.12.1 Threads
All pipe threads shall be taper-pipe threads in accordance with ASME B1.20.1 without exception.
10.12.2 Thread Sealant
Teflon tape shall be used for all threaded joints, except instrument air, where the design temperature is
200 °C or below. Other acceptable materials for thread lubrication are the following.
a. Teflon paste – Threaded joints to 200 °C
b. Copper paste – Threaded joints 200 °C to 620 °C
10.12.3 Seal-Welding Threaded Connections
Threaded connections requiring seal welding shall be made up wrench-tight without the use of sealing
compound or Teflon tape. All cutting oil shall be removed. The joint shall be tightened to full-thread
engagement. The seal welding shall be 6 mm minimum and shall cover all exposed threads.
Seal welding shall be done with electrodes not to exceed 3.2 mm in diameter using an amperage in the
low range to minimize distortion of the connection or part being welded. Care shall be taken to minimize
the amount of heat that goes into valves.
10.13 Fabricator-Installed Plugs
Fabricated spools, as well as vessels and equipment, have fabricator-supplied pipe plugs installed in
threaded connections. Threaded connections may be for temporary use, occasional use during operation
or an alternative connection. The fabricator generally supplies the most inexpensive plug. The field shall
check all plugged connections in piping and equipment to be certain the plugs comply with line class or
equipment class materials. The temporary connections may be seal welded, the occasional connection is
plugged with a line class plug, and the unused alternative plugged and seal welded.
10.14 Drawings
The field shall keep construction drawings current and updated in order to produce an accurate as-built
drawing.
11. Examination, Inspection and Testing
11.1 General
11.1.1 Examination Requirements
Examination requirements and limitations on imperfections shall be in accordance SES W01-F01.
11.1.2 Buttweld Examination
In addition to the code requirements, the type and extent of examinations for buttwelds shall be in
accordance with SES W01-F01.
11.1.3 Qualification
The written procedures to be used and the personnel qualification records shall be available to the SABIC
inspector for review. See ASME B31.3.
11.1.4 Spools
Check all spools for alignment and dimensions. Straighten when necessary. Gauge check the threads of
couplings and nipples in spools. Make sure each spool has been properly cleaned.
11.2 Inspection
The SABIC inspector shall be allowed to check materials or fabrication at any time. The inspector may
require tests and repairs or replacement of any material or work not in accordance with this specification,
the applicable codes or the applicable ASTM material specification.
11.3 Radiography
11.3.1 Minimum Requirements
The minimum requirements for radiography for the various piping material classes are given in
SES W01-F01. Where the ASME codes impose more stringent requirements, those requirements shall be
met. Acceptance requirements are to be in accordance with ASME B31.3.
11.3.2 Category D
Random radiographic examination is required on welded piping systems in Category D fluid service as
defined in ASME B31.3.
11.3.3 Radiography Requirements
Radiography requirements fall into two categories – random and 100 percent, described as follows:
a. Random Radiography – In addition to visual examination of all welds, the percentage shown for
each class in the Weld Summary shall be radiographed.
Each welder shall be examined on the percentage basis stated in the Weld Summary of this
specification. Welder quality shall be emphasized by including the first two production welds made by
each welder in the percentage basis.
b. 100 Percent radiography – In addition to visual examination, all welds shall be fully radiographed
in piping considered critical or in piping where weld quality assurance is required in accordance with
ASME B31.3, or ASME B31.1 when applicable.
c. Critical piping includes but is not limited to the following:
(i) Class 900 and above services
(ii) P4 and above chrome alloy piping on all pressure classes
(iii) Category M services
11.3.4 Extent of Radiography
Radiographs shall be of the complete circumference of the girth buttweld.
11.4 Branch Connection Examination
11.4.1 Ferritic Steels
A magnetic particle or liquid penetrant examination shall be made of all branch connection pressure welds
in the following:
a. All low and intermediate chrome-alloy steels
b. All carbon steel and carbon-moly steel in Class 600 and higher classes, in addition to severe
cyclic service in all pressure ratings
c. Austenitic Stainless Steels
A liquid penetrant examination shall be made of all branch connection pressure welds in austenitic
stainless steel and nickel alloys in Class 600 and higher classes.
11.5 Magnetic Particle Examination
The magnetic particle examination shall be made in accordance ASME B31.3 or ASME B31.1.
11.6 Liquid Penetrant Examination
The liquid penetrant examination shall be made in accordance with ASME B31.3 or ASME B31.1.
11.7 Hardness Tests
Hardness tests of welds shall be made in accordance ASME B31.3, except that the hardness of welds in
carbon steel shall not exceed 200 BHN with or without PWHT. Material classes with PWHT for service
require randohardness tests to ensure the quality of the PWHT.
11.8 Reports
The field shall furnish copies of the following reports to SABIC.
Copies for Brinnell hardness records of heat treated welds and copies of the time-temperatures cycle chart
for postweld heat treatment or annealing heat cycle used during pipespool fabrication and erection. These
charts shall identify the number of all spools treated for each heat cycle and a weld joint identification for
individual joints treated. The complete temperature cycle of heating, soaking, and cooling shall be shown.
12. Cleaning
12.1 Special cleaning
Special cleaning is indicated in the Line List, and on the Erection Drawing.
12.2 Erecting Cleaned piping
Spools that have been pre-cleaned are specially sealed. Special care must be used to ensure that foreign
material is not in any of the piping.
12.3 Recleaning
Should any grit be found in the piping, it must be re-cleaned.
12.4 Spool Inspection
Prefabricated pipe spools shall be visually inspected for cleanliness, shall have foreign material removed
from the inside, and shall have end protectors installed.
12.5 Flushing
After assembly and installation, the piping shall be cleaned inside to remove all loose material, either by
flushing or by blowing with air as a minimum. Rapid release of test water will give a good flush.
12.6 Chemical Cleaning
Chemical cleaning, when indicated in the Line List, and on the Erection Drawing, shall be performed in
accordance with SES P01-E27.
12.7 Component Protection
Pipe cleaning shall be performed such that soft seats of valves, control valves, and instruments are not
damaged.
13. Buried Installation
13.1 Coating
When permitted, buried metallic plant piping shall be coated either by treating and wrapping, or coatings
such as FBE, or polyethylene.
13.2 Burial
Burial of process piping is to be in accordance with SES P13-C01.
14. Pressure Testing
Hydrostatic testing of internal pressure piping shall be in accordance with SES P01-E15.