Piping ASME codes and standards

The codes and standards which related to piping systems and piping components are published by various organizations. These organizations have committees made up of representatives from industry associations, manufacturers, professional groups, users, government agencies, insurance companies, and other interest groups. The committees are responsible for maintaining, updating and revising the codes and standards in view of technological developments, research, experience feedback, problems and changes in referenced codes, standards, specifications, and regulations. The revisions to various codes and standards are published periodically. Therefore, it is important engineers, designers, and other professional and technical personnel stay informed with the latest editions, addenda, or revisions of the codes and standards affecting their work.

While designing a piping system in accordance with a code or a standard, the designer must comply with the most restrictive requirements which apply to any of the piping elements.

AMERICAN SOCIETY OF MECHANICAL ENGINEERS(ASME)

The American society of mechanical engineers (ASME) is one of the leading organizations in the world which develops and publishes codes and standards. The ASME established a committee in 1911 to formulate for the construction of steam and boilers and other pressure vessels. This committee is now known as the ASME boiler and pressure vessel committee, and it is responsible for the ASME boiler and pressure vessel code. In addition, the ASME has established other committees which develop many other and standards, such as the ASME B31, code for pressure piping. These committees follow the procedures accredited by the American national standards institute(ANSI).

ASME B31 : CODE FOR PRESSURE PIPING

The first edition of American tentative standard code for pressure piping was published in 1935. In view of continuous industry developments and increases in diversified needs over the years, decisions were made to publish several sections of the code for the pressure piping. Since December 1978,the American national standards committee B31 was reorganized as the ASME code for pressure piping B31 committee under procedures developed by the ASME and accredited by ANSI.

Listed below the following sections of ASME B31 codes for pressure piping,

ASME B31.1 Power piping

USAS B31.2 Fuel gas piping

ASME B31.3 Process piping

ASME B31.4 Liquid transportation systems for Hydrocarbons,liquid petroleum gas,anhydrous ammonia and alcohol

ASME B31.5 Refrigeration piping

ASME B31.8 Gas transmission and distribution piping systems

ASME B31.9 Building services piping

ASME B31.11 Slurry Transportation piping systems

ASME B31.1 : POWER PIPING CODE

ASME B31.1 Power piping code, prescribes requirements for the design, material, fabrication, erection, test, and inspection of power and auxiliary service piping systems for electric generation stations, industrial and institutional plants, central and district heating plants and district heating systems. It does not apply to piping systems covered by other sections of the code for pressure piping and other piping which is specifically excluded from the scope of this code.

ASME B31.1 does not cover the following:

1. Economizers, heaters, pressure vessels, and components covered by ASME boiler and pressure vessel code.
2. Building heating and distribution steam piping designed for 15 PSIG or less, or hot water heating systems piping for 30 PSIG or less.
3. Piping for roof and floor drains, plumbing, sewers, and sprinkler and other fire protection systems.
4. Piping for hydraulic or pneumatic tools and their components downstream of the first stop valve off the system distribution header.
5. Piping for marine or other installations under federal control.
6. Piping covered by other sections of ASME B31 and ASME section III.
7. Fuel gas piping within the scope of ANSI Z 223.1, National fuel gas code.
8. Pulverized fuel piping within the scope of NFPA.

USAS B31.2 : FUEL GAS PIPING

In 1955 a decision was made to publish a separate code of B31, code for pressure piping.Section 2 of B31.1 -1955 was updated and revised to publish as USASB31.2 -1968,fuel gas piping.No edition of this code section was published after 1968.This code withdrawn in 1988.

USAS B31.2 covers the design, fabrication, installation and testing of piping systems for fuel gases such as natural gas, manufactured gas and liquefied petroleum gas, air mixtures above the upper combustible limit, LPG in the gaseous phase or mixtures of these gases.

This code applies to fuel gas piping systems both within and between the buildings from the outlet of the consumer meter assembly and to and including the first pressure containing valve upstream of the gas utilization device.

This code does not apply to:

1. Vacuum piping systems.
2. Fuel gas piping systems with metal temperatures above 450 F or below -20 F.
3. Fuel gas piping systems within petroleum refineries, loading terminals, natural gas processing plants, bulk plants, compounding plants, or refinery tank farms, and so forth within the scope of USAS B31.3.
4. Fuel gas piping systems in power and atomic energy plants within the scope of USAS B31.1.
5. Fuel gas piping systems within the scope of USAS B31.8.
6. Fuel gas piping systems within the scope of USAS Z21.30.
7. Piping systems within the scope of USAS Z106.1.
8. Proprietary items of equipment, apparatus, or instruments such as compressors, gas generating sets, and calorimeters.
9. Design and fabrication of pressure vessels covered by the ASME boiler and pressure vessel code.
10. Support structures and equipment such as stanchions, towers, building frames, pressure vessels, mechanical equipment and foundations.
11. Piping systems for conveying premixed fuel gas air mixtures which are in the combustible or inflammable limits or range.

ASME B31.3 :PROCESS PIPING

This code prescribes requirements for the materials, design, fabrication, assembly, erection, examination, inspection, and testing of piping within the property limits of facilities engaged in the processing or handling of chemical petroleum or related products. The requirements of ASME B31.3 apply to piping for all fluids, including raw, intermediate and finished chemicals, petroleum products, gas, steam, air, and water ,fluidized solids and refrigerants.

In case of packaged equipment , the interconnecting piping with the exception of refrigeration piping shall be in compliance with the requirements of ASME b31.3.the refrigeration piping may confirm to either ASME 31.3 or ASME b31.5.

The requirements of ASME B31.3 do not apply to piping systems designed for internal gauge pressures at or above 0 but less than 15 psig provided the fluid handled is non-flammable ,non-toxic and not damaging to human tissue and its design temperature is from -29 C through 180 C.

The following piping and equipment are not required to comply with the requirements of ASME B31.3:

1. Power boiler and the boiler external piping.
2. Piping covered by ASME B31.4, B31.8 or B31.11, although located on the company property.
3. Piping covered by applicable governmental regulations.
4. Piping for fire-protections systems.
5. Plumbing, sanitary sewers and storm sewers.
6. Tubes, tube headers, crossovers and manifolds of fired heaters which are internal to the heater enclosures.
7. Pressure vessels, heat exchangers, pumps, compressors and other fluid handling or processing equipment, including internal piping and connections for external piping.

ASME B31.4: LIQUID TRANSPORTATION SYSTEMS FOR HYDROCARBONS, LPG, ANHYDROUS AMMONIA, AND ALCOHOLS

ASME B31.4 prescribes requirements for the design, materials, construction, assembly, inspection and testing of piping transporting liquids such as crude oil, condensate, natural gasoline, natural gas liquids, liquefied petroleum gas, liquid alcohol, liquid anhydrous ammonia, and liquid petroleum products between producers lease facilities tank farms, natural gas processing plants, refineries, stations, ammonia plants, terminals, and other delivery and receiving points.

The scope of ASME B31.4 also includes the following,

1. Primary and associated auxiliary liquid petroleum and liquid anhydrous ammonia piping at pipeline terminals, tank farms, pump stations, pressure reducing stations, and metering stations including scraper traps, strainers and power loops.
2. Storage and working tanks including pipe type storage fabricated from pipe and fittings and piping interconnecting these facilities.
3. Liquid petroleum and liquid anhydrous ammonia piping located on property which has been set aside for such piping within petroleum refinery, natural gasoline, gas processing, ammonia and bulk plants.
4. Those aspects of operation and maintenance of liquid pipeline systems relating to the safety and protection of the public company personnel, environment, property and the piing systems.

ASME B31.4 does not apply to

1. Auxiliary piping such as water, air, steam, lubricating oil, gas and fuel.
2. Pressure vessels, heat exchangers, pumps, meters and other such equipment including internal piping and connections for piping.
3. Piping designed for internal pressures at or below 15 psig regardless of the temperature and above 15 psig if design temperature is below -20 F or above 250 F.
4. Casing, tubing, or pipe used in oil wells, wellhead assemblies, oil and gas separators, crude oil production tanks, other producing facilities and pipelines interconnecting these facilities.
5. Petroleum refinery, natural gasoline, gas processing, ammonia, and bulk plant piping, except as covered within the scope of the code.
6. Gas transmission and distribution piping.
7. The design and fabrication of proprietary items of equipment, apparatus or instruments except as, limited by this code.
8. Ammonia refrigeration piping systems provided for in ASME B31.5, refrigeration piping code.
9. Carbon dioxide gathering and field distribution systems.

ASME B31.5 : REFRIGERATION PIPING

This section of pressure piping code, contains requirements for the materials, design, fabrication, assembly, erection, testing and inspection of refrigerant and secondary coolant piping for temperatures as low as -320 F except when other sections of the code cover requirements for refrigeration piping.

ASME B31.5 does not apply to the following:

1. Self-contained or unit systems to the requirements of underwriters laboratories or other nationally recognized testing laboratories.
2. Water piping.
3. Piping designed for external or internal gauge pressure not exceeding 15 psig .

ASME B31.8: GAS TRANSMISSION AND DISTRIBUTION PIPING SYSTEMS

A pipeline or transmission line is defined as that pipe which transmits gas from a source or sources to one or more large volume customers or to a pipe used to interconnect sources of supply.ASME B31.8 prescribes requirements for the design, fabrication, installation, testing and safety aspects of operation and maintenance of gas transmission and distribution piping systems, including gas pipelines, gas compressor stations, gas metering and regulation stations, gas mains and service lines up to the outlet of the customer’s meter set assembly.

Also included within the scope of ASME B31.8 are gas storage equipments of the closed pipe type ,fabricated or forged from pipe or fabricated from pipe and fittings, and gas storage lines.

The requirements of ASME B31.8 are applicable to operating and maintenance procedures of existing installations and to the update of existing installations.

ASME B31.8 does not apply to the following:

1. Design and manufacture of pressure vessels covered by the ASME boiler and pressure vessel code.
2. Piping with metal temperatures above 450 F or below -20 F.
3. Piping beyond the outlet of the customer’s meter set assembly.
4. Piping in oil refineries or natural gasoline extraction plants, gas treating plant piping other than the main gas stream piping dehydration and all other processing plants installed as part of a gas transmission system, gas manufacturing plants, industrial plants, or mines.
5. Vent piping to operate at substantially atmospheric pressures for waste gases of any kind.
6. Wellhead assemblies, including control valves, flow lines between wellhead and trap or separator or casing and tubing in gas or oil wells.
7. The design and manufacture of proprietary items of equipment, apparatus or instruments.
8. The design and manufacture of heat exchangers.
9. Liquid petroleum transportation piping systems.
10. Liquid slurry transportation piping systems.
11. Carbon dioxide transportation piping systems.
12. Liquefied natural gas piping systems.

ASME B31.9 : BUILDING SERVICES PIPING

ASME B31.9 applies to the following building services:

1. Water for heating and cooling
2. Condensing water
3. Steam or other condensate
4. Steam
5. Vacuum
6. Compressed air and other non-toxic and non-flammable gases

ASME B31.11 : SLURRY TRANSPORTATION PIPING SYSTEMS

Like ASME B31.4 this section of ASME B31, pressure piping code, specifies minimum requirements for the requirements for the design, materials construction, assembly inspection, testing, operation and maintenance of piping transporting aqueous slurries of non-hazardous materials such as oil, mineral ores and concentrates between a slurry processing plant or terminal and receiving plant or terminal. The requirements of ASME B31.11 also apply to the following:

1. Primary and auxiliary slurry piping at storage facilities, pipeline terminals, pump stations and pressure reducing stations, including piping up to the first valve of attached auxiliary water lines.
2. Slurry piping storage facilities and other equipment located on property which has been set aside for the slurry transportation system.
3. Those aspects of operation and maintenance of slurry transportation piping systems which relate to the safety and protection of the general public. Operating company personnel, environment, property and the piping systems.