×
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

Water quality

Water quality

Water quality

(OP)
Hi,

There is a requirement in API 610 for Centrifugal Pumps (Cl. no. 7.3.2.3) that the water quality to be used for Hydrostatic testing pumps with austenitic stainless steel materials shall not exceed 50 ppm w. Can anybody please clarify why this water quality requirement is not applicable for water to be used during the performance testing of the pumps?

In one of of the projects we are executing the hydro test is to be performed for 4 hrs and the combined performance and mechanical run test is scheduled for 6 hrs total. This way I suppose the performance test is to be regarded as more severe?

Thanks,
Tathagata Ghosh

RE: Water quality

"Hydrostatic testing of austenitic stainless steel vessels shall be done with potable quality water having a chloride content less than 50 ppm shall be used for hydro testing." is the way it is normally written.

Austenitic stainless steels are subject to stress cracking corrosion typically when the chloride concentration is over 200 mg/l for the entire service life. The service life is in terms of year.

Specifying the chloride content for a 4-hour test period is very conservative because the austenitic stainless steel will not be attacked in such a short time period.

Use of "potable water" is more appropriate as a standard for testing water. Most potable waters actually have a chloride content less than 200 mg/l.

Probably the reason that this is specified is that the pump manufacturers are probably not that familiar with the details of water quality.

RE: Water quality

There are probably 2 reasons why they don't call out a specific limit for the performance test.

1. API 610 has things that are inconsistant and not well thought out.  This may be one instance where it has simply been overlooked.

2. Water used on hydrotest tends to be drawn from a city water system, used once in the pump then dumped down the drain.  As such it is freshly treated water where the chlorine has not had a chance to decompose.

Water in test loops is typically reused with a relatively small amount of makeup water added.  Perhaps the experience of the API committee was that such water typically has a very low chloride level ?   

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