This Code prescribes requirements for materials and components, design, fabrication, assembly, erection, examination, inspection, and testing of piping. This Code applies to piping for all fluids including: 1 raw, intermediate, and finished chemicals; 2 petroleum products; 3 gas, steam, air and water; 4 fluidized solids; 5 refrigerants; and 6 cryogenic fluids. Also included is piping which interconnects pieces or stages within a packaged equipment assembly. Piping consists of pipe, flanges, bolting, gaskets, valves, relief devices, fittings and the pressure containing parts of other piping components.
It also includes hangers and supports, and other equipment items necessary to prevent overstressing the pressure containing parts. It does not include support structures such as frames of buildings, buildings stanchions or foundations. Requirements for offshore pipelines are found in Chapter IX. Also included within the scope of this Code are:. This Code prescribes requirements for the materials, design, fabrication, assembly, erection, test, and inspection of refrigerant, heat transfer components, and secondary coolant piping for temperatures as low as deg F deg C , whether erected on the premises or factory assembled, except as specifically excluded in the following paragraphs.
Users are advised that other piping Code Sections may provide requirements for refrigeration piping in their respective jurisdictions. This Code covers the design, fabrication, installation, inspection, and testing of pipeline facilities used for the transportation of gas. This Code also covers safety aspects of the operation and maintenance of those facilities. This Standard applies to on-shore pipeline systems constructed with ferrous materials and that transport gas.
Pipeline system means all parts of physical facilities through which gas is transported, including pipe, valves, appurtenances attached to pipe, compressor units, metering stations, regulator stations, delivery stations, holders and fabricated assemblies. Robleto, KBR N. Consumo, Sr. Ellenberger, Consultant T. Fetzner, BP Exploration Alaska. Stevick, Berkeley Engineering and Research, Inc. Graziano, Consultant E.
Rodabaugh, Honorary Member, Consultant. Schmidt Engineers - H. Frikken R. White Copper Development Association - A. Lemoff Edison Electric Institute - R. Code for Pressure Piping, which e Code sets forth deemed is under of The necessary for the safe construction of pres- American Mechanical Although silfety is the basic r ,r1",t1P,c"t, been accredited by the American National Standards alone will not Institute. The Committee is a one and of ilny is cau- all Code Sections current with new developments in tioned that the Code is not a design handbook; it does materials, construction, and industrial practice.
Piping covers a To the greatest possible extent, Code requirements for discretion to select ilny Section are stated in terms of basic and ally ilpplicable; however, it is cautioned that formulas. These are supplemented as necessary with tary rements to the Section chosen may be to ensure uniform application of necessary to provide for a safe piping for the and to guide selection and application of intended application.
Technical limitations of the vari- elements. The Code prohibits and ous Sections, legal and known to be unsafe and contains warnings where cau- bili ty of other Codes or Standards are some of the tion, but not prohibition, is warranted. Mandatory appendices contain c requirements and data for evaluilting and materials the user needs to carry out a stresses, reilctions, and movements associated with pres- recommendation in the main text sure, and other forces Nonmandatory appendices, which are written in man- d guidilnce and limitations on datory are offered for application at the user's applying and discretion.
The latest edition issued at least technical inquiries. Materials may be covered a Case. Cases for listing shall include evidence A Case is the usage and data to permit establishment of allow- when able stresses or pressure rating, maximum and minimum fication or when the limits, and other restrictions. Additional ments of the Code or criteria can be found in the for addition of materials or alternative constructions.
The Effective Date of a Case, however, be used after its or withdrawal, the Case was effective on the This when contains new Code original contract before sions. It is a compilation of the Edition and revisions of the and the to the Edition. ASME B Locatioll It is not considered to refer to a b This Code does not to edition of each of the standards and 1 and manufacture of pressure vessels cov- the individual Code paragraphs.
Users of this Code are advised 4 in oil refineries or natural of of these extraction gas plant piping other than the refer- the main gas stream in dehydration, and all other ence to that standard. Il This Code covers the 11 carbon dioxide transportation tion, inspection, and testing for the transportation of gas. Mandatory Appendix Q for scope diagrams. The of this Code are for under environment: the or cond i tions physical, conditions usually in the gas chemical, mechanical in which a material exists.
All per- operation. This Code is concerned with liquefied naturnl gas: natural gas liquefied by refrigeration n safety of the or pressure. Provisions encroachment: as used in this Code, is the portion of this Code shall be and mainte- of the route of a pipeline or main that lies within, runs in a parallel direction to, and does not cross the of a street, highway, or railroad.
S Qualification of Those Performing Inspections. Included within this definition are gas transmis- See VIII for additional and defi- sion and lines, which transport gas from nit ions applicable to offshore gas transmission production facilities to onshore locations, and gas stor-. If no gas plant element fitted in line with in a pipeline exists, the to the most downstream such as, but not limited to, valves, elbows, tees, of one of following: and closures.
CIIslomer's meier: a meter that measures gas delivered to gas service line: the piping installed between a main, a customer for consumption on the customer's premises. In such fuel line. Included in the station are and auxiliary pipe-type holder: any container or group of intercon- devices, such as valves, control instruments, control nected pipe containers installed at one location and used only for storing gas. Included and auxiliary devices an organic substance of high to ultrahigh such as valves, control control lines, the weight, is solid in its finished state, and at enclosure, and ventilation equipment.
The valve should be located in The specified limiting set or elon- joined on a line the angle of junction so as to ga tion is expressed as a of gage produce a in direction. Its values are in the various material pipe: a tubular including tubing, made for sale specifications under this Code, as a production item, used primarily for rnml,pu.
For minimum for copper does not exceed 0. Copper 0,60 Manganese 1. This is sometimes called joint, but is In all carbon steels, small quantities of certain residual preferred. It indicates a standard as copper, nickel, chromium, etc. Manganese 1. Molybdenum 0. Pressure is not and seamless pipe: a wrought tubular product made filler metal for the inside and outside welds is obtained without a welded seam.
It is manufactured by hot- from the electrode or electrodes. Additional typical afe other characteristics that are considered when ASTM A and ASTM which require both inside ing factors for construction, and outside welds and the use of filler metal. The and egress for the operation Clnd maintenance the have a butt joint wherein the installation of the fClcility. The ROW coalescence is produced by the heat obtained from resist- with the construction Clnd maintenance ance of the to the flow of electric current in a circuit the and is usually.
For definitions of gns conlrol criteria weld: a circumferential butt weld joining investigation terms, see Nonmandatory Appendix M. TIle is used without pressure and with filler metal the electrode and sometimes from a long-term hydrostalic slrengtli: the estimated mental source welding flux, or metal in per inch MPa in a wall that will cause ure of the at an average of fie-ill: a connection where a is left to divide a pipeline , hr when to a constant hydrostatic into test sections, or to a replacement pressure, section, or in the continuous line construction at a loca- tion such as a river or highway solvelll cemenl joinl: a joint made in thermoplastic by the use of a solvent or solvent cement that forms a tie-ill weld: a tie-in connection a continuous bond between the mating surfaces.
The wrinkle is delib- of piping to an actual shorter than its nominal introduced as a means of shortening the inside and it into position so that it is stressed meridian of the bend. Note that this definition does not apply to a pipeline bend in which incidental minor, in the erected thus compensating partially for the effects produced by the due to an smooth ripples are increase in temperature.
It is used in calculations or analysis for II1I1Xill1l 1Iwabie operating pressure MAOP : the maxi- compressive stress: the applied pushing force divided by mum pressure at which a pipeline system may be oper- the original cross-sectional area. P, of the fluid in a pipe of diameter, D, and is determined I11I1Xil11ull1 opemting pressure MOP : sometimes referred by Barlow's formula: to as maximum actual operating pressure, the highest U.
CustollJllry Unit s pressure at which a piping system is operated during a normal operating cycle. It depends on the material used, the location of the pipe, pressure: unless otherwise stated, expressed in pounds the operating conditions, and other limitations imposed per square inch kilopascals above atmospheric pres- by the designer in conformance with this Code. It may also be termed unit stress. The user of this Code tensile stress: the applied pulling force divided by the is cautioned that ambient a nd operating temperature original cross-sectional area.
A discontinu- ntpO'ritv of the. Mechanical damage can include denting, coating nondestructive removnl, metal metal movement, cold tion of qualified including the performance of the metal, and of the NDT method c1lld related activities but not includ- stresses. NOT : a method, such as radiography, fatiglle: the process of of, or acoustic emission, or n of, a crack as a result of ret:.
Imp or scmper Imp: an ancillary item of pipeline equip- used in a broader sense, surface preparation, ment, such as a launcher or receiver, with associated ments, dry film and manner of and for a into a pipe- are included, line or removing a pig from a corrosion: the deterioration of a material, a piggil1g: the use of any that results from an electrochemical reaction with its tool, or vehicle that moves the interior environment.
Ultrasonic examina- tion is used to determine wall thickness and to detect a chemical process of the presence of defects, """,odiDeof a or other material over a period of time, IIpmting: the qualifying of an pipeline or main for a higher maximum allowable operating pressure, cllrrent: a flow of electric charge, cllrrent density: the current to or from a unit area of an The anode and cathode may be dif- eiectrical isolalion: thecondition electrically sepa- ferent metals or dissimilar areas on the same metal rated from other metallic structures or the environment, surface, electrode: a conductor used to establish contact with an a liquid, liguefiable, Of mastic that, and through which current is transferred to after application to a is into a solid or from an electrolyte, protective, or functional adherent film, Coat- a medium ions that in an also includes wrap.
It is commonly used as a decorative fault CIIlTenl: a current that flows from one conductor to or or to another conductor due to an abnormal pipe-to-soil the electric potential difference cormection including an arc between the two. A fault between the surface of a buried or metallic current to may be called a ground fault structure ilnd the that is current. Resistivity data are to describe graphitic corrosion.
It occurs most intended circuit. The of a pipeline may be improved elastic limit: the maximum stress to which a materia! It is actually the ratio of stress to strain elements: in the elastic of a material. If determined by a a Identify those tasks for which the qualification tension or compression test, it is also called of the program apply. The tasks shall include Modulus or the coefficient of elasticity. An condition is defined in ASME span: a section of the that is unsupported. Quality Control consist of those planned, sys- if Establish a to periodically evaluate the tematic, and preventative actions that are required to effectiveness of qualification program, including ensure that products, and services will meet for the program based on the results Quality Assurance and.
The gram requirements are managed and find to prepare "ITln;,,",,,,'"'' II Identify the documentation area of responsibility.
Chapter I Materials and Equipment. All such materials and workmanship may be used. This para- materials and equipment shall be qualified for the condi- graph shall not be construed to permit deviations that tions of their use by compliance with certain specifica- would tend to affect weldability or ductility adversely. Materials and equipment fall into the following six Complete information as to chemical composition and categories pertaining to methods of qualification for use physical properties shall be supplied to the Section under this Code: Committee, and its approval shall be obtained before 11 items that conform to standards or specifications this material is used.
Rel- 14 of a type for which standards or specifications are refer- atively unimportant items that do not conform to a stan- enced in this Code but specifically do not conform to a dard or specification [para. Items that conform to stan- equipment is suitable and safe for the proposed service dards or specifications referenced in this Code e.
See section Impor- tant items of a type for which standards or specifications are referenced in this Code, such as pipe, valves, and For a of all referenced material Ductile iron manu- see Mandatory A. Removal of a por- pipe, or fitting to be used and tion of an steel line and reuse of the in determine material for the cond i tions at the same or lower anticipated. The selected material shall be adequately that the fracture resistant to the liquids and chemical that may be encountered.
See para. Partial for such equipment items are In other MPa ]. Unidentified steel and unidentified cases where this Code no for the new steel pipe may be qualified use at item, the intent is that the safety levels above 6, psi 41 MPa or for service Code shall govern, insofar as are close coiling or close by the In any case, the safety of equipment installed within the limits outlined below. All pipe shall be cleaned inside and outSide, if necessary, to permit All. For pipe NPS 2 ON and 10 lengths or less 1 set of tests from each length a sufficient of pipe shall be bent cold 11 to lengths 1 set of tests for each 5 lengths, but not less than 10 through 90 around a cylindrical the diame- Greater than lengths 1 set of tests for each 10 lengths, ter of which is 12 times the nominal diameter of the pipe, but not less than 20 without developing cracks at any portion and without the weld.
SlIIface Defects. All shall be examined for The pipe shall meet the requirements in this test, except gouges, grooves, and dents and shall be qualified in that the number of tests required to determine flattening accordance with the provisions of para. Unless the nomi- strength, or is unknown, and no nal wall thickness is known with certainty, it shall be tests are made, the minimum yield strength determined the thickness at points shall be taken as not more than 24, psi on one end each piece of If the lot of MPa.
Fol- 2 All test shall be selected at random. For pipe of unknown the in no case than 1. If the longitudinal Determine the average value of all tests joint can be determined with the for a uniform Jot. TIle value of shall then be taken as tudinal joint E Table The weld shall be i Hydrostatic Test. New or used pipe of unknown made under the most severe conditions lmder which and all used pipe, the of which is welding will be permitted in the field and using the corrosion or other shall be same as to be used in the field. The pipe shall retested hydrostatically either length by length in a mill- be considered weldable if the set forth in test or in the field after installation before being API are met.
At least one such test weld shall be placed in service.
Without fracture If in the weld the of APll cannot I-a, of an existing line of unknown and dimensions that have been used in natural and the reuse of the pipe in the same line or in a line vice only may be reused, provided that all of the operating at the same or lower pressure is are true: nrrlv, 1pr! The shall be leak- A careful indicates that it is free of tested in accordance with para. Used of known It is installed and tested in accordance with the specifications may be reused in accordance with the requirements of this Code for new. Chapter II Welding. Welding shall only when safe conditions This addresses the of pipe in are indicated, both and cast steel and covers butt and fillet welded in valves, and Prior to welding of any piping or related equipment this Code, a pro- Seal or welding operator shall be qualified for the established of threaded is permitted, but the seal before on any pipe, not be considered as to the installed in strength of accordance with this Code,.
Mn Welding in excess of 0. When welders the material qualified under API are employed on compressor shall govern. The references in para. These shall be followed, that for Alloy steels having weldability char- and acteristics demonstrated to be similar to these carbon steels shall be preheated, and stress relieved as nrp"wrlnP' 1 herein for such carbon steel. Stress relieving may also be advisable for All welders shall be requalified at least once each year. Welds in all carbon steels shall be stress relieved when the nominal wall thickness exceeds 1 Xi in.
The company or contrac- be used in applying the rules in paras. The shall be selected on a random basis by the wid th of the band that is heated to the company from each construction for examination. Care should be taken circumference or else the length of welds around the entire cir- shall be examined if the company chooses to cumference of the temperature shall diminish examine only a of circumference of each. If a when the construction involves such a limited is made, it shall be in accordance with API Pressure- 14 Valves shall con- devices shall conform to the requirements of form to standards and referenced in this this Code for valves in service conditions.
Code and shall be only in accordance with the All carbon-steel bolts and stud They may also be used with steel flanges with lapped, bolts shall have coarse threads having Class 2A dimen- male and female, large or and their nuts shaH have Class 2B dimensions. All alloy-steel bolts and stud bolts 2 Full-face should be used with all bronze of I-in. Bolts and stud bolts shall have with cast iron flanges, with raised-face steel flanges, a Class 2A dimension; their nuts shall have Class 2B or with lapped steel provided that the bolting dimension.
Bolts shall have ASME Standards regular 3 For steel to secure higher unit compres- heads or heavy hexagonal heads and shall sion on the metallic of a width less than ASME Standards hexagonal nuts conforming to the full male face of the may be used with raised the dimensions of ASME B The material for these Such nuts shall not be used for in which both shall be suitable for the service conditions encountered flanges are steel and the pressure exceeds and shall be softer than the flanges.
Yz in. For of are installed. BPV Code are not intended to apply to such assemblies as split or collars or to other field from those of welded details. ASME and e under this sec- para In the absence of such service the nominal diameter of the pipe, that the pressure shall be based on an consist- 1 DN are in NPS 4 DN ent with the philosophy embodied in this a nominal waH thickness of not less than Code and substantiated at least one of the following: mm. Threaded used for control equip- It is not the intent of this Code to the Taps than those permitted above shall use ofa a reinforcing sleeve.
Closure heads such as where dal [other than in spherical, or conical heads are d of the of the finished allowed for use under this Code. For closure heads not to connection Section VIII, Division 1 of the BPV Code, the maximum the nominal header wall thickness by allowable stresses for materials used in these closure para, Fish tails 2 the cross-sectional area that results from any and flat closures are permitted on NPS 3 DN excess thickness available in the branch wall thickness and smaller operating at less than psi kPa , over the minimum thickness for the branch Fish tails on pipe than NPS 3 are prohib- and that lies within the reinforcement area as defined ited, Flat closures on than NPS 3 shall be in e according to Section VllI, Division 1 of the 3 the cross-sectional area of all added reinforcing BPV Code.
Bolted blind in e , including that of solid weld metal that is conven- connections shall conform to para. All welded branch width shall extend a distance of times the header connections shall meet the following requirements: wall thickness on each side of the surface of the header a When branch connections are made to in the wall. In no case, shall it extend more than form of a connection or in a header or manifold times the thickness of the branch wall from the out- as a series of connections, the design must be side surface of the header or of the reinforcement if any.
The following provide design rules for g The material used for or saddle reinforcement the usual combinations of the above for may be of specifications differing from those of the pipe, excessive external loads. Special Requirements ring or saddle to reveal in the weld between Ratio of Nominal Branch branch and header and to during weld- Diameter to Nominal Header Ratio of Design and heat treating operations. I , j contributing to reinforcement of the branch connection. Hand The use of concave fillet welds is to further member and header do not exceed the thickness of the minimize corner stress concentration.
If member is thicker than the ual study, and sufficient reinforcement must be provided header and is welded to the the ends shall be to for the inherent weakness of such con- down to the header and continuous ribs to support the flat welds shall be made, In the case of hot or surfaces is and may be plugging fittings, use special requirement j , calculations, The is Reinforcement of cautioned that stress concentrations near the ends of however, reinforcement may be partial may defeat their reinforc- cases involving pressures over psig kPa , thin ing value, wall pipe, or severe external loads.
In addition to the 11 If a reinforcement member is and the requirements of It is recom- observed or measured between the inside of the fitting of fillet welds joining the and the outside of the pipe on installation, where t is. Appendix F, F-l through welds shall be 1. The reinforcing metal shall be added as a 1 Area is the area lying within the reinforce- combined the of which shall ment zone resulting from any excess thickness available the combined strengths of the reinforcements that in the run wall, Le" would be for the In no case shall any of a cross section be considered to apply to more than one or be evaluated more than once in a combined area, 2 Area is the area lying within the reinforce- b When more than two openings are to be ment zone resulting from any excess thickness available with a combined the minimum in the branch i.
An extruded outlet is defined as an outlet in which the extruded at the outlet has a height above the. Table The significance 0 0. In addi- Section is applicable to meeting the defini- lion to the expansion the linear and tion of unrestrained in para. A table containing approximate amounts of of restraints and supports for a piping system, or contraction per unit length for selected and in eVClluating the effects of piping on is provided in Table Cold-spring may be useful for mClintaining a Piping shall be designed to have sufficient reactions within limits.
Formal of attached and calculations shall be where reClsonable doubt and the. Section is appll- may need to be examined. Restrained M the bending moment across the cross sec- may include the following: tion, lb-in. The product 0. These stresses 3 is of uniform size, has no more than two points are often to evaluate but can be disre- of fixation and no intermediate restraints, and falls garded in most cases. It is the engineer's within the limitations of the following rical to determine whether such stresses should be evaluated. Y resultant of total strains, in. NOTE: No general can be offered that this empirical equa- e For occasional nonperiodic loads of short dun"- tion always yields conservative results.
It is not applicable to sys- tion, the value of k shall not exceed 1. Local stresses in or b caused or where ME is the resultant intensified moment range from loads may further limitations in con- one stress state to another. The resultant intensified of fatigue. The value necessary. If such in branch connections caused pressure or external sion is not made in the manufacture of the or stresses at structural discontinuities.
Attach- ments must meet the of para. Unequal coftlo. Where it is necessary to attachment, as at an the pipe, Lateral thrusts at branch connections may greatly welded to the member only; the support increase the stresses in the branch connection itself, be attached to the encircling member and not to the unless the fill is consolidated or other The connection of the to the mem- sions are made to resist thrust.
At these loca- Where there is doubt as to the of restraint tions, the movement, if unrestrained, may be of consider- friction, calculations shall be indicated able tude.
If connections are made at such a shall be installed, location to a relatively unyielding line or other fixed object, it is essential that the interconnection shall have Free water and hydrocarbons at certain combinations of These services, such as water, gas b The quality of the gas in the and electrical supply, sewage systems, lines pipeline, or by the pipeline considered and ditches, buried power and communication when facilities. Measures shall be taken to streets and etc. Noncombustible d A designed, constructed, and operated nitrogen, compounds, carbon in with the of Location Class 1 etc.
Carbon dioxide tainment in any location; however, additional measures to internal corrosion in the presence of free are necessary to protect the integrity of the line in the water. Increased of the gas stream may presence of activities that might cause damage. One of foretell the at cooler the measures by this Code is to lower the stress which may negatively affect operations.
This activity A change in may affect and is quantified by Location Class and relating compressor capacity calculations. For effects of heavy the design of the pipeline to the appropriate design hydrocarbons on the of for ductile fractme factor. Hydrogen sulfide is "population density index" to determine design, con- highly toxic and contributes to corrosion in the presence struction, and They also of water.
Oxygen contributes to corro- pressure. To simplify use of this the. Certain mixtures of oxygen and gas above Construction Types A, B, and D were eliminated and the lower explOSive limit can create an explosive with the same term used for condition. This Division is a Location due to in terminology.
Class 1 where the factor of the pipe is to g Pipelines constructed prior to the of or less than 0. Classes established in with previous edi- b Loeatioll Class 2. Location Class 4 includes areas occupancy. Count the number intended for where multistory buildings are prevalent, where traffic human occupancy within each 1-mi 1.
For is or dense, and where there may be numerous this purpose, each dwelling unit in a multiple other utilities Multistory means four or unit building is to be counted as a more floors including the first or ground building intended for human occupancy. The of basements or number of basement b It is not intended here that a full 1 mi 1. It is intended, a In addition to the criteria contained in para. Class 3, the Location Class 2 or Location Class 3 may b near of public assembly or con- be terminated ft m from the nearest centrations of people, such as churches, schools, multi- in the cluster.
A Location Class 1 is any l-rni l. The orientation of require a design factor of 0,6; see the strength test is established by the pipe product specification depending on pipe size and method of pipe making, Conse- quently, pipe may have a qualified strength in an axis orientation locations for that does not conform to the orientation of the principal loading construction and or stress, The user is alerted to be aware of the standard test due consideration shall be orientation used to determine conformance of pipe to the mini- to the possibility of future of the area, mum strength requirement of the selected grade, and to consider If at the time of planning a new pipeline this future whether the intended uses or anticipated service conditions of development likely to be sufficient to the pipeline system warrant supplementaltesling of the strength the Location this shall be taken into consideration properties in other orientations.
Alternatively, when energy to arrest propagating pipe fracture. To ensure that the energy to arrest a propagating fracture. CVN O. In the 0' event the is to a mill test pressure, then P For API 5L pipe, the minimwn values shall retest pressure rather than the initial mill test be the of those the equations above or It is mandatory to use a liquid as the test in those by API 5L for PSL 2 pipe.
Because the proposed rule would not significantly or uniquely affect the Indian tribal governments, the funding and consultation requirements of Executive Order do not apply. Homeland Security Department. Section I of Appendix B to Part would be revised to read as follows:. Climate Change documents in the last year. If service conditions change the risk classification, the interval between inspections shall be re-evaluated. Join Date Jun Posts
Annex G of all tests in place after installation where the test pressure API 5L 45th Edition contains additional exceeds the mill test pressure. This is not to for be construed to i1l1ow an pressure or energy values, pressure in excess of that for by para, ,1. Strength,S, in Para. Mechanical crack 1 5 value for new pipe qualified under of wrap, heavy- para.
When fabricated such as connections for main line valve Location Class 1, Division 1 0. Also see section If the actual value is than the minimum value of a mechanical property, the actual value may be used where it is permitted by the Code, such as in para. The factor in Table The nal joint factor shall be in accordance with Table The ature derating factor shall be in accordance with Table Pipelines, mains, and service lines!
Crossings of roads, railroads without casing: a Private roads 0. Crossings of roads, railroads with casing: a Private roads 0. Parallel encroachment of pipelines and mains on roads and railroads: a Private roads 0. Fabricated assemblies [see para. Compressor station piping 0. Near concentration of people in location Classes 1 and 2 [see para. Where meter size, and flow rate allows, consider installing meter Table Pipe Class E Factor when installing rotary or turbine meters.
Classes 12, 22, 32, 42, 52 1. High gas velocities in piping increase turbulence and pressure drop lnd contribute to exces- sive sound pressure levels lerodynamic noise and can Table T, for Steel Pipe l! To minimize the potential surement equipment shall be properly for damage to existing surface or subsurface structures, isolated from piping to help design of the plan and profile shall consider accidental shutoff situations caused by the accuracy of the methods to be in locating ure due to lightning strikes and electrical transients and existing structures, maintaining required clearances to safety hazards caused by fault currents, Elec- from structures, tracking the of the trical isolation equipment for corrosion control pilot head and reamer during drilling and should not be installed in buildings unless tracking of the reamer during pullback.
Line pipe longi- 1 Qllalifications, Drilling contractors shall main- tudinal seams are not generally regarded as susceptible tain written and installation procedures to fatigue due to operational in most crossings to be by the directional natural gas service. Drilling equipment operators and per- crack growth due to sonnel responSible for establishing the location of the for pipe containing seams where pilot head and reamer drilling shall the expected lifetime accumulation of full MAOP be qualified by training and lOy,, ,,,,'lm,rlO may exceed the following number of occurrences: tation of the contractor's U.
Cllstomary Ullits 2 Geoteclinical Evaillatiolls. Geotechnical evalua- tions should be considered at the crossing location to establish subsurface conditions. Loads on, and stresses in, the string during installation shall be 51 Uuits evaluated to ensure protection of the pipe against yield- f 9. N , pipe due to combined effects of external pres- sure, axial and bending. See directional where drilling references in Nonmandatory F factor from Table Location Excavation Smailer ON -. When such clearance cannot be mains shall be by distance or to the sha lJ be barricades from accidental damage by vehicular traffic or or other causes, material.
Buried mains shall any other underground structure not used in conjunc- be installed with a cover not less than 24 in. When such clearance cannot be Where this cover provision cannot be met, or where attained, precautions to the main shall be external loads may be excessive, the main shall be such as the installation of material or casing. Where or other oper- Roads, or Streets. If the end sealing is of a type that will retain additional protection shall be provided, for sug- the maximum allowable operating pressure of the carrier gested methods to provide additional protection,] the shall be for this pressure and Covel' Rcqllircll1ellls Except for off- factor of 0.
All construc- tion work performed on in accordance e Additional Protection. The pipe with the of shal! J 1 A barrier or marker may be installed 2 the surface of the above or around the para. If a physical lowered into the ditch to find barrier is the conflict with the right-of- indicate the pipe might have been way maintenance activities should be coated, cal barrier or marker methods include 3 the fitup of the joints before the weld is -a a concrete or steel barrier placed above the made.
In addition, the bend shall Deflection of Bend in Pipe meet all other provisions of this section. Mitered bends are the Nomina! Pipe Size Axis. NPS 18 ON 50 2. The first column expresses the maximum the total deflection at each miter shall deflection in an arc length equal to the nominal outside not exceed 90 deg. This may penetration. II Deleclioll of Gouges lind Grooves Wrinkle bends with sharp kinks shall not be 1 The field provided on each sh lll of wrinkles shall be measured along be suitable to reduce to an minimum the and the distance between chances that gouged or pipe will into the shall exceed the diameter of the On finished or main.
Care shall be thickness is not less than the minimum this exercised to ensure that the heat of does not Code for the conditions of uSilge. Insert patch- a HOlding, and Stringing. The depth a dent shaH be minimum yield it is important that measured as the gap between the lowest of the stresses imposed on the pipeline construction be min- dent and a prolongation of the original contour of the imized, Except for offshore pipelines, the pipe shall fit pipe in any direction. Slnck are not at the longitudinal weld or any circumferential ited by this where laying conditions render shall be removed, All dents that exceed a maximum their use advisable.
When dents are coating by such means as the use of rock shield material, of the shall be cut out as a cylinder. Insert or by making the initial fill with rock-free material suffi- and pounding out of the dents is prohibited. All hot shall be installed by and grooves [see above], trained and experienced crews, 2 Stress concentrations that mayor may not involve a notch may also be created by a The metallurgical notch burn ill be determined as follows: visible evidence of the caused by arc burns shall be removed pro- arc burn has been removed grinding, swab the ilrei! A spot vided the grinding does not reduce the remaining wall is evidence of il metililurgicill notch ilnd indicates that additional thickness to less than the minimum by this grinding is necessary.
Nitrogen or carbon diox- 2 Control the gas pressure at the site of the work ide can be used for this purpose. If a pipeline or main containing gas is to be 3 After a cut is made, close all slots """nmID'; the may be carried out in accordance or open ends with tightly fitted canvas, or other with b , or the may be first disconnected from all suitable materials.
This is doubly if the is done. The pOSSibil- ity of striking static within the must not or equipment upon which be overlooked as a source of welding or done with an inert or Whenever the accidental ignition in the air continuous with air in such a manner a of mixture may be to cause injury combustible mixture does not form in the facility at the or property precautions, such as the following, work area shall be taken: of the in the of the 1 Prohibit and open flames in the area.
Introduce a rapid and All piping continuous flow of gas into one end of the line and vent shall be tested after construction to the requirements of the air out the other end. The gas flow shall be continued this Code except for fabricated assemblies without interruption until the vented gas is free of air.
If the vent is in a location where is not practical. The gas flow shall then for the purposes of or do not be continued without interruption until all of the air a construction retest. The recommended test medium is water. When either of these media are whenever it is that cer- the public shall be removed to a safe distance tain conditions may gases. When a during the test and shall be gas is used as the test medium, test pressure shall with protective equipment.
Both not exceed the maximum values stated in sour gas flammable gas tests must meet the test Tables The user is cau tioned that the release of stored energy b The pressure test medium of in a gas test failure can be Significantly more hazardous Table When with Class Locations 3 and 4 need not if, at the time a formal risk assessment is recommended, the are first ready for pressure one or are identified, and measures and both the following conditions exist: are to minimize additional risks.
Subse- to or than that in Table 84L3, quent prior to reuse should be considered if the stabilization of temperatures and test assembly to have ing has been achieved. The follOWing are pressure test for human occupancy. I, Division 0. If an operating company decides that the maximum operating pressure will be than the design pressure, a corresponding reduction in the prescribed test pressure may be made as indicated in the Pressure Test Prescribed, Minimum column.
If this reduced test pressure is used, however, the maximum operating pressure cannot later be raised to the design pressure without retesting the line to a higher test pressure, See paras. Refer to section N-7 of II Each main, and related equipment that Nonmandatory Appendix N for a list of rec- will operate at less than kPa shall be tested ords for retention. In tilis case, the soap test Strength of the Pipe, but in Excess of psig may be used to locate leaks if all joints are accessible kPa. Steel piping that is to at hoop stress during the test. In Class 2, 3, and 4 coatings are used that would seal a Locations, such piping shall be tested in accordance with seam.
If such are the leak test pressure Table that gas or air may be used as shall be psig kPa. All Table If the test indicates that a leak to the maximum test stress, until the pressure is exists, the leak or leaks shall be located and reduced to the maximum operating pressure, unless it can be determined that no undue hazard to Written shall be estab- ing all leaks in the section tested and shall be lished for Procedures shall consider the selected after giving due consideration to the volumetric characteristics of the gas to be the need to content of the section cll1d to its location.
This isolate the from other connected facilities, and the exercise of and experienced the the constructed to those rather than numerical bJe for its operation. Standard wall thicknesses for shall be fully kPa maximum working pressure and safety such as laying conditions at several depths of cover flow-monitoring and emergency are shown in Table Duc tile iron gas is introduced to ensure that each valve is mechanical shall conform to the ANSI A Written start-up procedures shall be ANSI!
AWWA 1l. Ductile iron and shall following: with other of n the be mechanically and qualified meet the appropriate operational Code. Such joints shall be assembled in accordance with b all functional tests be performed and accepted standards or in accordance with the manufac- c all necessary safety be operational turer's written recommendations.
Ductile iron pipe shall be laid in accor- Underground ductile iron pipe shall be a and procedures installed with a minimum cover of24 in, mm unless b cleaning and drying results prevented by other underground structures. Where suf- c records of pipeline monitoring ficient cover cannot be provided to protect the from external loads or damage and the pipe is not to withstand such external loads, the shall be cased or to the c loilll Reslmillf.
Standards or in accordance with the manufacturer's b Allowable Vailies of s alld f The values of written recommendations. Thickness, in. Units defined "standard" dimension ratio. The less than that shown in Table ,2,2-l. Manufacturers of the p design pressure, should be contacted for S for thermoplastic design basis shall be used. The Standard Dimension Ratio System enables the user to select a number of different sizes of pipe for a piping system, all of which will have the same design pressure. When plastic materials of the same design strengths are used, the same Standard Dimension Ratio may be used for all sizes of pipe instead of calculating a value of t for each size.
The manufacturer should be consulted for advice on maximum pressure ratings 2 50 2. Shilll conform to the applicable b Reinforced plastic pipe and fittings para. Plastic c The wall thickness for RTP shall not be less shall conform to the icable than that listed in Table The Plilstic piping shall conform. Lll c. Suffi- 3 The surfaces must be dry, and free cient clearance shall be maintained between plastic pip- of material that may be deterimental to the joint. Plastic tubing, and fit- excess cement shall be removed from the outside of tings may by the solvent cement method, adhe- the joint.
The joint shal! A solvent cement joint shall not be heated to 2 Solvent cement adhesive joints, and heat- accelerate the of the cement. PA-ll components may be joined to PA-ll 2 Sound socket heat-fusion joints the use components, and PE components may be joined to of a device that heats the surfaces of the PE PE and PA-ll shall not joint uniformly and simultaneously to the be to each other. The completed joint must not be dis- made of different of materials may be turbed until properly set, provided that properly for joining.
Sound 4 Provisions shall be made to clamp or otherwise cannot normally be made between loose or very materials from until the adhe- tight-fi tting components. Nominal elastomer shall not cause deterioration in one another's Coefficients of chemical and physical over a period , Thermal Expansion 2 The tubular stiffener to reinforce the General ASTM D, end of the pipe or tubing shall extend at least under Material x 5 in. The rough PA PM1 8,5 4,3 or and shall not be a force fit in the pipe PE 9,0 5,0 or tube, Split tubular fittings shall not be used, PE 10,0 5,6 3 Since pull-out resistance of r,.
Plastic tions of components are to damage by mis- -1 offsets cuts, kinks, or other forms of damage -2 anchoring may cause failure. Care shall be exercised during han- aligning the pipe and dling and installation to such -4 in the case of fittings the a Plastic andtubingshallbecarefully use of types and of the pipe in for cuts, gouges, and other before use, and any pipe or tubing or shal! Thermoplastic pipe, 5 Backfilling shall be performed in a manner to shall be from long-term exposure to firm around the piping, The material direct sunlight.
Encased shall be able to withstand necessary to remove any without or abrasive material that could " " f l l r I V P below the design limitations and after insertion. The end of the vent or contain gas that may escape the plastic pipe in shall be closed before insertion. Burial protected a 1 buried thermoplastic or tubing piece or other means from crushing or shearing from shall have a minimum wall thickness of external loading or settling of backfill, 0. If piping is to be laid in the carrier pipe where it may be subjected to soils that may it, the piping shall be temperatures, the carrier pipe can be constricted to by suitable rock-free materials before backfilling is com- point where the capacity is affected or the wall pleted, Plastic shall not be blocking, could be crushed and leak, To avoid this, one or more Well-tamped earth or other continuous shall of the following shall be taken: be used.
For general installation see para. In addi- 11 Pressure Testing. All tion, the following measures shall also be taken for sure tested after construction and being trenchless installations of plastic in operation to demonstrate that it does not 1 Protecting Pipe b Tie-lns. Because it is sometimes necessary to -a Precautions shall be taken to avoid divide a or main into sections for and or pulling the string over piping, and other neces- or abrasive surfaces that may damage the pipe during sary appurtenances, it is not that the tie-in installation. The tie-in -b Visual pipe surface shall be and after installation.
This If damage scratches, section tested and shall be selected after! The minimum pressure not than 15 times the maximum and pressure or 50 kPa , whichever is elsewhere in this that The bends shall be free of cracks, or other evidence of air, or water may be used as the test medium. All testing after con- dance with a above shall be made with elbow-type struction shall be done with due for the safety of and the public during the test. Field-fabricated miter fittings are not permitted. When used for gas mains, copper Injurious gouges or pipe or tubing shall conform to the following out and replacing the portion as a cylinder in accordance with para.
All hot taps shall be installed by 2 Copper or tubing shall not be used for trained and crews. Purging of plastic mains and ser- age of 0. This is equivalent to a trace provisions of paras, and f. The maximum distance from any point on an 4 pipe or tubing shall not be used for floor to an exit shall not exceed 75 ft 23 m , mains where strain or external loading may the measured along the centerline of aisles or walkways.
Valves installed in copper provide a convenient of escape and shall pro- lines may be made of any suitable material vide unobstructed passage to a of Door by this Code. It is recommended that the inside without a key. Any fence that may of bronze, copper, or brass. The filler material used so as to provide a convenient opportunity for alloy or silver a place of Any such gates located wi for ft m of any compressor plant building shall tubing shall not open outward and shall be unlocked or of being pipe wall thickness equivalent from the inside without a key the area size of Schedule 40 steel i.
Provision All electrical equipment and wiring installed in gas shall be made to harmful action where transmission and distribution stations shall copper is connected to steel. J commerCially available permits. Sufficient open space the introduction of should be around the building to permit the ties of entrained liquids into the compressor. All compressor sta- therefrom. Liquid separators shall defined in NFPA A minimum of two exits shall be ASME Boiler and Pressure Vessel provided for each floor of a main compressor separators constructed of and fittings no inter- building, basements, and any elevated walkway or nal welding may be constructed in accordance with form 10 ft 3 or more above ground or floor ASME Fire protection facilities established by the is should be in accordance with the American exceeded.
Insurance Association's recommendations. If the fire Pressure relief or other suitable A pressure relief valve or blown down. Blowdown shall extend to a location where the of Code. Vent lines provided to exhaust the station or surrounding area. Vent lines have sufficient sions of a 1. For additional considerations, to a distribution shall be provided with emer- see para.
An automatic device sor station buildings by means of which all gas can be designed to shut off the fuel gas when the blocked out of the station, provided there is another shall be provided on each gas engine adequate for the distribution system. These gas injection. The distribution manifold shutdown facilities can be either automatic or manually vented simultaneously. All gas at the wrong time and cause an on the compressor units shall be equipped with shutdown or distribution shall be installed.
It is recommended that all compart- and automatic or manual blowdown processes and ments of the muffler be manufactured with vent slots must be designed to the automatic or holes in the baffles to prevent gas from being trapped of hydrogen sulfide, vapors; or free in the muffler. Ventilation shall be ample to hazardous to the or the public. All piping within a com- pressor station shall be tested installation in accor- dance with the of para. Special care is in valves and controls shall be identified The the location of relief valve vents releasing LPG function of all important gas pressure piping shall be to the to prevent accumulation of the heavy identified or color codes.
The following are for for applicable to compressor station fuel gas ing only: a All fuel gas lines within a compressor stRtion that Consideration should be number of engines instil lied and to the The following are pro- within a short of time. A check valve shall ple piping, to and connections to the main also be in main air line on the immediate shall of steel and use a F, outlet side of the Rir tank or tanks.
It is recommended per Table Valves having shell components that for cooling the air Rnd the made of ductile iron may be used to the limita- moisture and entrained oil be installed between the start- tions in para. The provisions of d Suitable provision shall be made to prevent start- para. Rnd while work is in progress. All oil 1 on 0,72 within gas compressing stations shall be con- 2 0. Pressure, psig kPa Clearance, rt m. SI Units. C minimum clearance between pipe containers or in.
The selection of Bottles shall be buried with the top of each con- these factors depends on the Location Class in which tainer below the normal frost line but in no case closer the site is situated, the clearance between the pipe con- than 24 in. Suitable types of protective devices to wires to the small diameter of the bottle end prevent overpressuring of such facilities include a relief valves of the closure for cathodic purposes a local- prOVISions Section VIII ized thermit welding process charge not to exceed 15 b pilot-loaded back-pressure d Such bottles shall be given a test in relief so designed that failure the mill and need not be retested hydrostatically at the or control lines will cause the time of installation.
Careful the time of This pressure is by be used. For a or sure of 50 kPa above the maximum main, the maximum allowable pressure shall pressure. Relief valves shall be installed in accordance with d When service lines are connected to the pipeline capacity or main, the limitations set forth in paras. This paragraph applies to natuxal gas.
Suitable types of pro- 2 weight-loaded relief valves. It 6 a series regulator as described in should not be used where it might cause an interruption para. Pressure Distribution Systems. Some of ing. In some cases it may be necessary to raise the pres- the suitable of protective to over- sure slightly to permit proper of the service customers' 1 a monitoring regulator 4 Isolate the low-pressure 2 a relief valve systems.
Such methods may include of the check will vary on conditions. This device may be either a relief Systems valve or an automatic shutoff that shuts if the pressure II If the maximum allowable on the inlet of the service regulator exceeds the set pres- the distribution sure [60 kPa or and remains closed until a service regulator manually reset. The relief valve may than that recommended by the manufacturer for be either built into the service regulator or may be a the maximum gas pressure at the regulator inlet unit installed downstream from the service reg- 3 a valve seat made of resilient material This combination may be used alone only in cases to withstand abrasion of the gas, impurities in gas, and where the inlet pressure on the service does cutting by the and to resist permanent not exceed the manufacturer's safe working pressure deformation when it is the valve of the service and it is not recommended.
Precautions shall be taken to prevent unauthorized of any valve that will make All control lines shall be from falling or other foreseeable causes of and installed to t1"m;,a" to anyone control line from both the and the overpressure device. In doing this, however, the assumed remote g that may contain liquids shall be protected must be limited to the capacity of the by heating or other suitable means from damage due system to transmit gas to the remote location or to to the of the remote relief whichever h Piping in which liquids may accumulate shall be is less.
Where the device consists of an addi- detrimental external mechanical i. These checks Suitable shall be taken to shall be conducted to determine that the will corrosion. If If identifica- piping systems, such as fluid-filled, temperature- tion other than that already provided by the manufactur- responsive devices. Onshore block valves or shall be made of suitable material and shall shall be installed in new transmission be capable of withstanding the maximum and minimum time of construction for the purpose operating pressures and temperatures of the piping or pipeline for maintenance and for response to equipment to which they are attached.
Blow- down valves shall be installed where necessary for the 1 See The sizes and capacity of the connections 2 the time to blow down an isolated section for blowing down the line shall be such that under 3 the impact in the area of gas release emergency conditions the section of line can be blown nuisance and any hazard resulting from down as rapidly as is blowdowns d This Code does not the use of automatic 4 continuity of service valves nor does the Code that the use of automatic 5 and maintenance flexibility of the valves developed provide full protection to a piping system.
Their use and installation shaH be 6 future development in the vicinity of the at the discretion of the company. Where a valve is 4 5 mi 8 km in areas of predominantly Location installed in a buried box or enclosure, access Class 4 to the operating stem or mechanism is The box The defined above may be to permit or enclosure shall be installed in a manner to avoid a valve to be installed in a location that is more external loads to the main.
Valves shall be vaults or for valves and pressure- in distribution in pressure-limiting, or sta- accessible locations to reduce the time to shut down a tions, etc. In determining the dance with the spacing of the valves, consideration should be given to n Vaults and pits shall be designed and constructed the operating pressure and size of the mains and local in accordance with good structural engineering nr;,rtlri" conditions as well as the number and type of to meet the loads that may be imposed on them.
In the design of vaults and for pressure- limiting, and pressure-regu If a blowdown valve is involved, it shall be located where the gas can d entering and within vaults or be blown to the without undue hazard. All valves shall or liquids through the opening and to avert strains in. The number of bends and offsets or pit so that its exposure to shaH be reduced to a minimum, and shall be to a minimum. If all open- installed shall not be located under a vaultor pit shall be with tight-fitting covers without where workmen can on them when or open holes through which an explosive mixture might be the vault or pit, unless such parts are suitably Means shall be provided for the internal fmn'"m,prp before the cover.
Some of the important factors to consider in in square feet m 2 is less than 20 to I, no additional the location of a vault are as follows: ventilation is required. Vaults b No vault containing gas should be located as far as is from water, elec- by means of a drain connection to any other substruc- tric, steam, or other facilities. Vents associated with the or equipment b When installed within a building, the service must not be connected to the vault or pit ventilation.
Iocation near c The ducts shall extend to a height above of gas service line entrance, and whenever practi- adequate to mixtures that might cal, the meters shall be installed at the same location. The of the ducts shall be Neither meters nor shall be installed in bed- equipped with a suitable fitting or vent rooms, or bathrooms; under combustible stair- head designed to matter from entering ways; in unventilated or inaccessible or closer or the The effective area of the than 3 ft 0. The industrial customers or installations where gas is used.
AS ME B Pits and vaults hous- may be installed at other readily accessible locations. All meters and regulators shall be installed in such a Individual vents shall be for each regulator. The use of standard weight close all Iron or aluminum case meters shall not be used at a thread is prohibited. Meters and service regula- mum of 12 in. Where these cover measures are taken to such deterioration. A suitable tures, less cover is permitted of these service lines that are to excessive posed loads are cased or bridged or the as required under the conditions: ately 11 If the nature of the utilization equipment is such b Service lines shall be properly supported at all that it may induce a vacuum at the meter, install a back- on undisturbed or well-compacted soil so that pressure regulator downstream from the meter.
The material used for the backfill shall 1 the utilization equipment may induce a back- be free of pressure. Valves All service 11 Valves used as service line valves shall meet the vents and relief vents, where shall terminate of section and para. At locations where c A valve in a meter bar that may during floods, the meter to be bypassed does not qualify under this antiflood breather vent fitting shall Code as a service line valve.
Other of valves may be used test pressure, and duration set forth in where tests by the manufacturer or by the user indicate para. Where the pressure is less than kPat the e All service lines at a pressure greater steel service shall be at least than 10 psig 69 kPa lines NPS 2 DN kPa pressure. The curb box or It is recommended that service lines be con- to the during installation. The 2 When a service line is to be installed connection to the top of the main is to mini- or driving, and coated steel is to be mize the possibility of dust and moisture being carried not be used as the bore pipe or drive from the main into the service line, the as part of the service line unless it has been Each service line shall be tested withstand the boring or driving in the type of after construction and before being in service soil involved without significant to the coating.
At the shall extend past the outside face of the foundation a where the terminates, the space between the sufficient distance to reach undisturbed soil or thor- conduit and the service line shall be sealed to prevent compacted backfill. At the where the sleeve the entrance of any gas The casing terminates inside the foundation or wall, the space shall be vented at a safe location. When used for service lines, ductile iron shall 2 A plastic service line installed underground meet the of section