Piping Materials Class . . . 1

[Itayabla]

Hi All,

Would someone please explain to me what a piping material class (AKA materials specification) is, why it's needed hence what it is used for? Unfortunately I haven't been able to find a satisfactory explanation on the net.

Many thanks in advance guys.

 

[StevenHPerry]

A/k/a piping specification.

The document lists the material(s) of construction (e.g. A106-B), the allowed components (e.g. Pipe, Elbows), wall thicknesses (e.g. schedule standard), limitations on use (i.e. water service, 285psig, 200°F) and any number of other useful bits of information.

It keeps everyone on the same page, from the guy making the P&IDs to the guy installing the line in the field.

Process Industry Practices might have some samples freely available.

- Steve Perry

http://www.linkedin.com/in/stevenhperry

 

[pennpiper]

Steven H Perry has given you a good answer. I am only going to add to what he has told you.
If the Plant has 10 different commodities (Chemicals and utility services) each with three different maximum Operating Pressure and Temperature ranges then you will end up with thirty (30) different Piping Material Line Class Specification Categories. All of these have different material or wall Schedules, Gaskets, Valve types, Valve Trims, depending on the chemical, pressure and Temperature. All of these Line Class Specs are normally "Packaged together in one master document referred to as the Line Classes.

 

[Mr168]

Pennpiper nailed it. In my experiences in the power industry, it's used primarily for commodity code reference. I've also used them prior to construction or issue of isometrics to anticipate NDE requirements (based on wall thicknesses, temp/pressure, and applicable code), and for referencing the service type based on the line ID.

 

[BigInch]

Think of it as a recipe book for a piping engineer. If I know the product, pressure and temperature I just look in the recipe book, find out that Class "A600" works for those criteria, then I can just pick from the "A600" material list and find any standard component I might want to use, knowing that they have already been checked for that maximum pressure and temperature. No need to dig through 14 different manufacturer's catalogues, for a tee, valve, gasket, flanges, bolts, nuts, look in some piping code for design formulas, size the wall thicknesses ... all that's already been done and what works is right there on the list and ... you might even find it in the company stocks. Make the configuration you want, check the pipe stress ... and on to the next job.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

 

[Itayabla]

Gents,

That's helped clear things up I think. Thanks very much for you assistance.

@ BigInch,

You said: "If I know the product, pressure and temperature I just look in the recipe book, find out that Class "A600" works for those criteria..."

Are you referring to the so-called 'Index of Piping Material Classes' here. So that, knowing those conditions (i.e. temp, press and service) I then reference the index to find the suitable PMC for further details?

Thanks

 

[BigInch]

Attached you'll find a class "CS2B0" (I imagined that number, in this case one of possibilities to select from.) A refining company may have many, many different line classes, whereas a pipeline company may only have 10, or even less.

Provided that you have those service conditions listed at the top, you will find that all material listed thereunder generally "works" for those conditions, unless there is some unusual exterior loads, strange configuration, stress or other unusual problems. An engineer should at least begin designing a specific piping system by selecting the appropriate components from items on such a list.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv