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Up Topic Welding Industry / Technical Discussions / ASME B31.3 Process Piping Hydrostatic / Leak Testing
- - By pang_cs Date 06-12-2007 13:30
Deari All, Good Evening.

Have anyone had good experiences or had handled before the waiver / avoiding of conducting hydrotesting under ASME B31.3 but still compliance to it for :

Low pressure steam line
Medium pressure steam line
White liquar / black liquar line
Chemical piping line.
Parent - By chall (***) Date 06-12-2007 13:45
It is a common discussion that surprises me. 

B31.3 is the "standard" for engineering, selection of materials, fab/construction, inspection and testing.  Why would you want to waive one of the fundamental steps, that is part of the overall design philosophy that makes the completed system safe?

All that said, it is the owner's Engineer who has the responsibility for deciding whether or not to waive hydro following new construction. 

Charles
Parent - - By G.S.Crisi (****) Date 06-12-2007 20:42 Edited 06-13-2007 00:02
My personal experience.
Back in my days of erector engineer I was in charge of the construction of a natural gas compressing station. In this case, the applicable Code is ASME B31.8. We, the contractor, were strictly within schedule, but the client wanted to put the station in operation 45 days before contractual terms.
We were hurried by the client to do everything we could to achieve this objective. With the PERT diagram on hand, I demonstrated to the client that the piping erection was within the critical path and the most we could do was to advance the handing over of the plant by 15 days.  
Then the client ordered me in writing to cancel the hydraulic test of the piping and replace it by 100% Rx examination of all the welds.
With the approval of the high management of my company I did what I was ordered, worked plenty of overtime, including saturdays and sundays, and eventually the plant was put to work as the client wished. Of course, the client reimbursed my company for the extra expenses we had run into.
This happened 35 years ago.
Giovanni S. Crisi
Sao Paulo - Brazil
Parent - - By pang_cs Date 06-13-2007 09:41
Sorry to post an old and common question as the situation still occurs today as mentioned by Crisi.

Back to topic, especially the steam line. the situation is RT (10%) & Inspection has been carried out, I believes the desinger have not considered the weight of water during hydrotest (support are under designed), time constrain, additional works are not encauraged for pipe supports.
But can a steam line (low or medium pressure) be obmitted from hydrotesting? Some desinger have defined it as Category D but with no other restorative measures except insulation, it is not harmful, but as we know, most of the people have conducted hydrotesting for these lines. i know it is Owner and Desinger's responsible but it is subjective, right?
Parent - - By G.S.Crisi (****) Date 06-13-2007 18:29
As far as underdesigned pipe supports are concerned, the problem is easy to solve: put temporary supports made of scrap structural steel, wooden wedges, bricks and everything you can imagine and is available at the job site.
Giovanni S. Crisi
Parent - - By pang_cs Date 06-14-2007 02:09
Morning Mr Cris,
Is clear they also not inteded to do that (Category D and claimed with Owner agreement), they might consider / be challenged if the Category D defined for steam service is weak (according to B31.3 App M, if Catergory D; in-service test is allowed).
Parent - By pang_cs Date 06-15-2007 04:36
Hi, any significant differences to apply the steam service line to B31.1 between B31.3? In B31.1, the codes covers steams, can be classified as non-boiler expternal piping system. Consequently alternative initial service test is allowed.
Up Topic Welding Industry / Technical Discussions / ASME B31.3 Process Piping Hydrostatic / Leak Testing

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