Hydro test on HDPE

By TimGary (****)

Date 08-12-2009 18:47

I don't have a copy of B31.3 with me to check, but I suggest you look at it very closely.
About 10 years ago, I was writing welder qualification and hydro testing procedures for HDPE to B31, and was suprised to find that the testing parameters are much more stringent than for steel.
I always figured it was becase HDPE, in industrial settings, is often used to carry caustic materials, but that's just an opinion.
Tim

By js55

Date 08-12-2009 19:14

B31.3, Chapter VII, Section A345.4.2 (a), unless design temp is above test temp in which case you have to run the calc in (b).

By Pipeslayer (**)

Date 08-12-2009 19:52

I've seen the calculation but is that for qualifing the procedure? what I have is a 160 design pressure with a 240 psi max per customer spec. Thats the test pressure 240 using the 1.5 X design. It just does not sound right to me.

By js55

Date 08-12-2009 20:21

For qualifying a procedure you either run a burst test per A328.2.5(b) or run the hydrostatic calc in (c).
Considering that I am mathematically challenged, I always run the burst test. Though keep in mind I use these sections for FRP not HDPE, but the non metallic requirements are the same.