Hydrotest - Temp

Date 10-13-2008 18:16

John boy,

I cannot find that the 2006 edition addresses specific temps. Under B31.3 344.1 it states "The possibility of brittle fracture shall be considered when conducting leak tests on brittle materials or at low temperatures".

The companies I am familiar with will not allow hydro testing below 40 degrees F.

The 1999 edition of B31.3 states under 345.4.1 "Test Fluid. The fluid shall be water unless there is the possibility of damage due to freezing or to adverse effects of water on the piping or the process".

I don't know if this info will help but I would not hydro test below 40 degrees F unless an EXPERIENCED piping engineer had SIGNED OFF for the test to take place.

By G.S.Crisi (****)

Date 10-13-2008 18:44

Yes, 40 ºF (or 4 ºC) is the minimum water temperature I've seen specified by many engineering companies.
Giovanni S. Crisi
São Paulo - Brazil

By 3.2 Inspector (***)

Date 10-13-2008 18:28

A good rule of thumb, dont hydrotest at temperatures below the freezing point.
However, things still get build and tested in areas of the world which has cold climate, it's simply done by adding some "anti freeze fluid" to the water.
A flush and blowout of the system is required straight after the test.

And yes - brittle fracture has to be considered.

3.2

By fbrieden (***)

Date 10-14-2008 02:48

Don't you have the code book (B31.3) from which to reference?

By fit.to.a.flange (*)

Date 10-14-2008 06:01

All,

Thanks for the input. I remembered looking thru B31.3 and could not find anything specific to this matter. Yes, common sense tells that no hydrotest could perform above boiling point or below freezing limit. The client's specification also does not address this subject. But if I am the Owner, I will probably set my ranges to suit the local conditions and bearing in mind that some countries, the summer period could sour to a very high temp when one is to perform such testing.

Regards, John boy..

By Kix

Date 10-15-2008 13:15

I've been on a few jobs where we hydroed below freezing, but we had a big rain maker box that was heated with steam to supply the water. We'd hydro the line, drain it, and blow it down with air either all day or over night. I wish they would stick to the 40 deg rule because when your hand shoes get wet and it's below freezing, it doesn't make for a great day. ;-)