Does B31.3 require drain lines to be pressure tested or 100% NDT?

[KevinNZ]

Does B31.3 require all drains and other lines open to atmosphere, and no operating pressure, to be pressure tested or if you can not hydro then 100% NDT?

In our case we have an acid tank over flow line, which is piping, it is not Category D, so needs a hydro test? I guess we could do an pneumatic test. 110% of 0 design pressure = 0 bar test pressure!

 

[XL83NL]

NDE, hence RT, requirements depend on fluid service. Atmospheric piping may be designated Category D Fluid Service; cat D allows for 0% RT.
For leak testing; refer to para 345.1(d), which has a clause that may exempt leaktesting if a line is open to atmosphere, and downstream of the last shutoff valve.

 

[KevinNZ]

XL83NL

The b31.3 2008 version I have (we usually use B31.1 which we have up to date) does not have 345.1(d), What does that clause say?

There is no out in 345.1 (B31.3 2008) and appendix M does not have low pressure check for Category D, just looks at weather fluid is toxic or damaging.

Kevin

 

[XL83NL]

Is there a specific reason you're using an older version of B31.3?
If you have a contract that specifies a certain Code edt, or a contract that's been signed just after June 2009, that would make sense.
Otherwise, you're copy is outdated and pretty much useless for future work, and you should get a new Code edition.
Where you mentioned B31.1, I assume you meant B31.3.

 

[KevinNZ]

XL83NL

too long a story why we do not have the latest b31.3. Enough to say till now we did not need it.

 

[bernoullies123]

Kevin,

Clause (d) of 2010 edition states:
(d) Unless specified in the engineering design, lines open to the atmosphere, such as vents or drains down-stream of the last shutoff valve, need not be leak tested.

This was raised in 1983, but was only updated in the code in 2010.

Interpretation 2-31 query was on toxic liquid discharging to atmosphere and the response was:

Reply: The minimum hydrostatic test gage pressure is as calculated by Eq. 24, which for 0 psi, design pressure is O. Note that a pressure differential is required for fluid flow.