Piping Material Specifications

This topic provides basic information and guidelines for understanding, different Piping Material Specifications used in Piping Material Engineering.

Piping specification is a document specifying each of the components. Different material specifications are segregated in different “Piping Class”. Identification of the “Piping Classes” depends on each Design Engineer.

Input Documents for Preparation of Piping Material Specification:

Piping Specification Index indicating Piping classes, Service Fluids, basic material, corrosion allowance, design pressure and temperature and specific requirements like NACE compliance, statutory regulations etc.

Approval on these specific requirements shall be obtained from Process department/Process Licensor or client.

Piping Material Index is provided by Process Licensor.

From the P&IDs/PEFS obtain the maximum size of lines covered by each piping class/service fluid.

Components included in Piping Material Specification:

• Pipes
• Fittings
• Flanges
• Gaskets
• Bolting
• Valves
• Specialties

The selection of piping material requires knowledge of corrosion properties, strength and engineering characteristics, relative cost and availability.

Piping Elements:

Piping elements are classified based on Material of Construction

Codes

A group of general rules or systematic procedures for Design, fabrication, installation and inspection prepared in such a Manner that it can be adopted by legal jurisdiction and made into Law.

Standards

Documents prepared by a professional group or committee which are believed to be good and proper engineering practice and which contain mandatory requirements.

American Standards

1. American Petroleum Institute (API)
2. American Iron and Steel Institute (AISI)
3. American National Standard Institute (ANSI)
4. American Society of Mechanical Engineers (ASME)
5. American Society of Testing Materials (ASTM)
6. American Welding Society (AWS)
7. American Water Works Association (AWWA)
8. Manufacturers Standardization Society of Valves and Fitting Industry-Standard Practices (MSS-SP)

For the Codes and Standards to be used, refer to the Bid document/Basic engineering package and year of issue to be adhered to for the Project.

Commonly used piping system design codes are:

1) ASMEB 31.1- Power Piping

2) ASMEB 31.3- Process Piping

Year of Issue of the Code must be specified in the Bid Package/Basic Engineering Packages. If not specified, clarification/confirmation shall be obtained from Client or latest edition shall be adhered to at the time of contract.

Specifications and Standards Accepted by ASME B 31.3

1 ANSI-American National Standard Institute

2 API-American Petroleum Institute

3 ASCE-American Society of Civil Engineers

4 ASME-American Society of Mechanical Engineers

5 ASNT-American Society for Non-destructive Testing

6 ASTM-American Society for Testing Materials

7 AWS-American Welding Society

8 CDA-Copper Development Association

9 CGA-Compressed Gas Association

10 EJMA-Expansion Joint Manufactures Association

11 ICBO-International Conference of Building Officials (Earlier known as UBC–Uniform Building Code)

12 MSS-Manufacturers Standardization Society of the Valve and fitting Industry

13 NACE-National Association of Corrosion Engineers

14 NFPA-National Fire Protection Association

15 NIST-National Institute of Standards and Technology (Earlier known as NBS –National Bureau of Standards)

16 PFI-Pipe Fabrication Institute

17 PPI-Plastic Pipe Institute

18 SAE-Society of Automotive Engineers

ASME Dimensional Standards

Major ASME standards referred for the piping engineers are:

1) ANSIB1.1-Unified Inch Screw Threads

2) ASMEB1.20.1-Pipe Threads general purpose–(ExANSIB2.1)

3) ASMEB16.1-Cast Iron Pipe Flanges and Flanged Fittings

4) ASMEB16.3-Malleable Iron Threaded Fittings.

5) ASMEB16.4-Cast Iron Threaded Fittings

6) ASMEB16.5-Steel Pipe flanges and Flanged Fittings

7) ASME B 16.9-Steel Butt welding Fittings

8) ASME B 16.10-Face to face and end to end dimensions of Valves

9) ASME B 16.11-Forged steel Socket welding and Threaded fittings

10) ANSI B 16.20-Metallic Gaskets for pipe flanges –ring joint, spiral wound and jacketed flanges

11) ASME B 16.21-Non Metallic Gasket for pipe flanges

12) ASME B 16.25-Butt Welding Ends

13) ASME B 16.28-Short Radius Elbows and Returns

14) ASME B 16.34-Steel Valves, flanged and butt welding ends.

15) ASME B 16.42-Ductile Iron Pipe Flanges & Flanged Fittings –Class 150 and 300

16) ASME B 16.47-Large Diameter Steel Flanges –NPS 26-60

17) ASME B 18.2 1 & 2 -Square and hexagonal head Bolts and Nuts–(in & mm)

18) ASME B 36.10-Welded and seamless Wrought Steel Pipes

19) ASME B 36.19-Welded and Seamless Austenitic Stainless Steel Pipes.

ASTM Standards

ASTM has 16 sections 71 Volumes

Section0- Index

Section1- Iron & Steel Products-7 Volumes-736 Standards

Section2- Non Ferrous Metal& Products-5 Volumes-678 Standards

Section3- Metal Test Methods & Analytical Procedures-6 Volumes-651 standards

Section4- Construction-10Volumes-1601standards

Section5– Petroleum Products Lubricants etc-5 Volumes-577 standards

Section6-Paints,RelatedCoatings& Aromatics-4Volumes-795Standards

Section 7- Textiles-2 Volumes-325 Standards

Section 8- Plastics-4 Volumes-556 Standards

Section 9- Rubber-2 Volumes-287 Standards

Section 10- Electric Insulation & Electronics-5 Volumes-487 Standards

Section 11- Water &Environmental Technology-2 Volumes-763 Standards

Section 12- Nuclear, Solar & Geothermal energy-2 Volumes-248 Standards

Section 13- Medical Device & Services-1 Volume.

Section 14- General Methods & Instrumentation-3 Volumes-336 Standards

Section 15- General Products, Chemical Specialties & end use products-9 Volumes-1498 Standards

Unified Numbering System (UNS)

The UNS number itself is not a specification, since it establishes no requirements for form, condition, quality etc. It is a unified identification of metal sand alloys for which controlling limits have been established in specifications elsewhere.

The UNS provides means of correlating many naturally used numbering systems currently administered by Societies, trade associations, individual users and producers of metal sand alloys, thereby avoiding confusion caused by use of more than one identification number for the same material and by the opposite situation of having the same number assigned to two different materials.

UNS establishes 18 Series numbers of metals and alloys. Each UNS number consists of a single letter prefix followed by five digits. In most cases the alphabet is suggestive of the formula of metal identified.

1. A00001 –A99999 –Aluminum & Al. Alloys.
2. C00001 –C99999 –Copper & Copper alloys.
3. E00001 –E99999 –Rare earth & rare earth like metal & Alloys.
4. L00001 –L99999 –Low methug metals & alloys
5. M00001 –M99999 –Miscellaneous non-ferrous metals & alloys.
6. N00001 –N99999 -Nickel & nickel alloys
7. P00001 –P99999 -Precious Metals & alloys
8. R00001 –R99999 -Reactive & refractory metal & alloys.
9. Z- Zinc & Zinc alloys
10. D – Specified Mech. Properties of Steels.
11. F – Cast Iron & Cast Steels.
12. G – AISI & SAE Carbon & alloys Steels.
13. H—AISIH Steels.
14. J –Cast Steels.
15. K –Misc steels & Ferrous alloys.
16. S –Stainless Steels.
17. T –Tool Steels.
18. W –Welding Filler Metals & Electrodes

The basic material or the generic material of construction is specified by the Process Licensor for the process fluids. The Piping Engineer is expected to detail out the same based on the Codes and Standards.

The Piping Design Criteria originates from the Line List which specifies design conditions with respect to pressure and temperature

In absence of this data, the Piping Engineer considers the following for strength calculations

• Design Pressure as 10% higher than the maximum anticipated operating pressure.
• Design Temperature as 25° above the maximum anticipated operating temperature.
• When operating temperature is 15° C and below, the design temperature and the anticipated minimum operating temperature.

The design should meet the requirements of the relevant code.

The material used shall be in accordance with latest revision of standards.

If ASTM materials are used, then the materials adapted by ASME/ANSI should be preferred.

The basic criteria for selection of material:

• Suitability of material for service fluid from corrosion point of view.
• Suitability of material for given design conditions (Design pressure & design temperature
• Life cycle cost

The selection of materials in general shall follow the norms below: (ref. ASME B31.3)

1. Carbon steel shall be used up to 800 ^oF (425 ^oC).
2. Low temperature steel shall be used below -20 ^oF (-29 ^oC)
3. Alloy carbon steel shall be used above 800 ⁰F (425 ^oC).
4. For corrosive fluids, recommendations from the Process Licensor to be followed.