Selection of appropriate Piping Code B31.1/B31.3 ( Stress Analysis)

[waqassaleem12222]

Hi,

If we are given only temperature, pressure, fluid service and piping material. Can we select which B31 code will be applicable to it? Lets take a case as an example.

T = 400 C
P = 4000 KPa
Material = A106-B
Service = High Pressure Steam
Applicable code will be B31.1 or B31.3?

Can the code selection can also be based on these above mentioned parameters? If yes, then which part/section of code B31.1/B31.3 deals with it. I read that code selection is based on application. e.g in a process plant, piping attached to boiler will deal with B31.1 and rest will be B31.3. If the service is steam and coming from the boiler in a process plant,, i want to ask at what point in piping the code changes from B31.1 to B31.3? Till which point in this steam piping should be designed per B31.1 and which part comes under B31.3? I mean if we are not given the governing code, and nor the application , just pipe layout and isometric, and only above mentioned 04 factors/parameters are available, can we decide which code to use for stress analysis? and how we can justify our selection or may argue with the wrongly selected code ( if in case may be) by the Piping layout personal.

Thanks,
Waqas

 

[C2it]

Code applied could not be defined by process/material considerations. The plant type must be addressed.

The plant area to which each B31 Code is intended to apply is clearly defined in the first few paragraphs of the Code.

It is not the responsibility of Piping Layout personnel to decide where a particular Code applies, rather it would be the Owner / Client's decision.

Regarding you steam question, I have worked on many refinery projects, generally to B31.3, where the steam generation (HRSG etc.) was to B31.1 but all steam / feed water piping outside of that unit was to B31.3. The actual break point would normally be the battery limit isolating valves.