Common PVF Acronyms

Ho’well Do You Know These Industry Acronyms?

Below are some common terms you might hear in the PVF world. Do you know what the abbreviations stand for?

Click on the acronym to reaveal the correct meaning.


Pipe, Valve & Fittings

The collective term used to refer to the components and materials used in plumbing, industrial, and construction applications related to fluid and gas handling systems. PVF components are used in a wide range of industries, including manufacturing, petrochemicals, oil and gas, construction, water supply, wastewater treatment, and more.


Single Random Length

A length of pipe between 18 and 22 ft long.


Double Random Length

A length of pipe between 38 and 40ft long.


American Society of Mechanical Engineers

ASME is one of the oldest standards-developing organizations in America. Founded as an engineering society focused on mechanical engineering in North America, ASME is now multidisciplinary and global


International Organization for Standardization

Technically this one’s not an acronym, but it’s still important! Because “International Organization for Standardization” would have different acronyms in different languages (IOS in English, OIN in French for Organisation internationale de normalisation), their founders decided to give it the short form ISO. Whatever the country, whatever the language, they are always ISO.

Howell’s Quality Management System is ISO 9001:2015 certified.


American Society for Testing and Materials

An international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.


Drain Waste Vent

Pipe and fittings used for low pressure drain, waste and vent systems.


National Pipe Thread

US National technical standards for screw threads used on threaded pipes and pipe fittings


British Standard Pipe

A set of technical standards for screw threads that has been adopted internationally (except in North America) for interconnecting and sealing pipes and fittings by mating an external (male) thread with an internal (female) thread


Deutsches Institut für Normung

German Institute for Standardisation – The German national organization for standardization and is the German ISO member body. DIN is a German Registered Association headquartered in Berlin. There are currently around 30,000 DIN Standards, covering nearly every field of technology, including PVF.


Threaded Both Ends

Pipe that has thread on both ends.


Threaded One End

Pipe that has thread on only one end.


Manufacturers Standardization Society

Technical association organized for development and improvement of industry, national and international codes and standards for Valves, Valve Actuators, Valve Modification, Pipe Fittings, Pipe Hangers and Pipe Supports, Flanges, & Associated Seals.


Canadian Standards Association

A Canadian standards organization which develops standards in 57 areas.


Canadian Registration Number

A number issued by each province or territory in Canada by an authorized safety authority for any boiler, pressure vessel or fitting that operates at a pressure greater than 15 psig (1 barg).


American National Standards Institute

A nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.


Nominal Pipe Size

A North American set of standard sizes for pipes used for high or low pressures and temperatures.


Polyvinyl Chloride

One of the most common types of plastic used today. PVC pipes are strong and lightweight, while also being relatively inexpensve.


Chlorinated Polyvinyl Chloride

Similar to PVC, CPVC has added chlorine, allowing it to withstand higher temperatures than PVC pipes.


Electric Resistance Welded

A welding process where metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint.


Submerged Arc Welded

A welding process that involves creating a fusion between metals using an electric arc that’s generated between a continuously fed consumable electrode and the workpiece.


Mill Test Report

Mill Test Reports provide information about the quality and specifications of the materials used in a particular product. It’s typically associated with metals and alloys, especially in industries where the material’s properties are crucial for safety and performance.

They provide assurance that the materials are suitable for their intended application and help ensure the quality and safety of the finished product.

Howell has an online system giving customers 24/7 access to MTRs. Sign up here

Thanks for playing!

We hope you enjoyed the industry acronym mini-game, and maybe even learned a little something too!

Remember, our PVF specialists are always ready to answer any Pipe, Valve & Fitting questions you might have. Complete the inquiry form below and we’ll be in touch ASAP.

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    MSS SP-114 Heavy Pattern Fittings vs Light Pattern Fittings

    Stainless Steel Fittings – Heavy Pattern vs Light Pattern

    Stainless steel fittings were originally manufactured to the same dimensions and wall thicknesses as iron fittings and the ANSI B16.3 standard. Later the MSS SP-114 standard was written for Class 150 stainless steel fittings, which was based on ANSI B16.3 dimensions. Today there are serval different patterns that vary in dimensions, wall thickness and weight. Stainless steel fittings to MSS SP-114 specification are to be used when ASME B31 piping code is required. When compared it is easy to see that the lighter pattern fittings are not the same in quality and should be used in limited applications since they do not fully comply with ASTM A351.

    This table summarises the differences between the standards:

    Heavy Pattern MSS-SP-114 Light Pattern
    Rating Class 150 150 PSI
    Applications Industrial Processes Residential and non-critical plumbing
    Material Grades Available in 304 and 316 Available in 304 and 316
    Dimensions Heavy duty wall thickness and larger diameter Significantly less material with thinner wall
    Benefit / Value Long lasting, better erosion protection Costs less
    CRN Registered Yes No
    Temp (⁰F) Class 150
    (Castings) PSIG
    -20 to 150 300
    200 265
    250 225
    300 185
    350 150(a)

    The pressure rating for the MSS SP fittings is 300 psi @ 150 ⁰F and is identical to class 150 malleable fittings. As the process temperature increases, the pressure rating decreases.

    Note: (a) Permissible for service temperature up to 366 ⁰F, reflecting the temperature of saturated steam at 150 psig.

    MSS SP-114 Heavy Pattern

    Light Pattern

    Organizations & Standards

    • ASTM – American Society for Testing and Materials
    • ANSI – American National Standards Institute
    • ISO – International Organization for Standardization
    • MSS – Manufacturers Standardization Society
      • Further built upon the standards written by ASTM, ANSI, and ISO with more detailed requirements.
    • ASME – American Society of Mechanical Engineers
      • Standards are derived and compiled from the standards released by all four organizations.
    • CRN – Canadian Registration Number
    • ANSI / ASME B1.20.1 – defines the thread dimensions and tolerances.

    Stainless steel fittings are built to a variety of specifications and are not all the same.

    Please consult with one of our product specialists if you’re unsure of the fittings you require.

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