×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Leak Testing of Valves - Power Plant
4

Leak Testing of Valves - Power Plant

Leak Testing of Valves - Power Plant

(OP)
When purchasing valves from a valve company is leak testing of valves by a supplier usual practice or a requirement of a standard? (Not pressure testing, just checking if there is any leakage over the valve seat at MAWP or MOP).

If it is normal practice to leak test valves, would it be satisfactory to test a full batch or only a sample.

On a separate point, has anybody any good or bad feedback on the following types of valve manufacturers:

Bollfilter
Bray
Camau
Friulco
Jasta
Krombach
LVF
Neway
S+S
Sisto
Zwick

RE: Leak Testing of Valves - Power Plant

I have used Zwick and have seen Bray.  I am unaware of problems with either.

It is a normal practice to require API STD 598 compliance certification for seat leakage.  Some project require testing a sample.  Some may test all critical valves. Testing costs time and money.  Neither leak testing nor certification assure that the valve won't leak after plant hydrostatic testing.

RE: Leak Testing of Valves - Power Plant

(OP)
How does API STD 598 fit in with ASME/ANSI. Is there any requirement under ASME B31.1 or 31.3?

RE: Leak Testing of Valves - Power Plant

API 598 is a stand-alone document and has no relationship with ANSI/ASME B31.1 or B31.3 construction codes. API 598 is referenced as the testing standard for valves made to API downstream valve standards such as API 600 (gate valves) and others. The only ANSI/ASME standard that comes close to API 598 is B16.34, which specifies testing procedures but does not address leakage rates. API 598 does address leakage rates.

RE: Leak Testing of Valves - Power Plant

Certainly the manufacturer should test the valves at assembly.

There are many standards for testing.  "Bubble Tight" is not one of them although it is mentioned frequently and is completely meaningless unless a procedure is also involved.  

Other useful specs are MSS-SP61 and API 6D.  

FCI 70.2 is most frequently invoked for control valves but it is important to understand that 70.2 is merely a measure of the machining and assembly.  The procedure (except for Class V) specifies testing at nominal 50 psi.
There is no relaible procedure to extrapolate what the leakage will be at other pressures, temperatures, or with other ladings.  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources