×
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

Air Bleed Valve at Pressure Gage - Required?

Air Bleed Valve at Pressure Gage - Required?

Air Bleed Valve at Pressure Gage - Required?

(OP)
Hello
Hope this is the right forum for this question.

I am installing an inline sediment filter on a domestic water piping system. We want to install a differential pressure gage mounted above the filter to determine when the filter needs to be changed. The small 1/8” dia. pipes feeding the gauge will be tee’d off the main line from the top. Here’s a link to the pressure gage we’re using;

http://www.dwyer-inst.com/Product/Pressure/Differe...

Do I need to install air bleed valves at the inlets to the gage? My thought is it shouldn’t really matter what’s applying pressure to the gage itself, whether that be the fluid directly, or what will likely be the case, trapped air in the piping. The air and water have to be at the same pressure so as long as something is exerting the force.

I would like to avoid installing air bleed valves as there is limited space. Would really appreciate any thoughts or if someone has had a similar experience with a similar setup.

Thanks,
Dan Sheppard

RE: Air Bleed Valve at Pressure Gage - Required?

If the lines to the DP guage are equal and short and you're not measuring in mbar, then you don't need an air bleed IMHO.

Probably better off in the plumbing forum TBH, but its ok here.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Air Bleed Valve at Pressure Gage - Required?

(OP)
Thanks LittleInch.

The pressure differential shouldn’t be more than 10-15 PSI. With the incoming pressure at around 50-60 PSI.

Am planning to keep the branch lines of equal length and short as possible. I figure as long as both lines are the same length and we’re measuring differential pressure it shouldn’t really matter anyway as the effect on both sides of the gage is equal.

I might post this thread in the plumbing forum as you suggest.

Thanks again.
Dan

RE: Air Bleed Valve at Pressure Gage - Required?

The plumbing forum is rather dead compared to this one so I wouldn't bother, but if it's deep plumbing issue you want then try it first.

So long as you keep the possible mis match on head down to 1psi (2.3 ft) i.e. if one pipe is full and the other empty then you should be good to go for this usage. Its relative height from tapping point to guage that is important not length as there is no flow. So long as you try to get a gradual rise from your pipe to the guage you're good. Don't introduce dips or high point loops.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Air Bleed Valve at Pressure Gage - Required?

The plumbing forum may be little used, but I would not think it is dead.

Maybe we are all zombies and nobody told us.

Putting pressure gauge(s) in line with filters is common to determine the need for changing/cleaning the filter elements.

The unit you are using looks a bit pricy. Typically I have seen two simple pressure gauges mounted upstream and downstream. The filter manufacturer should give you what the preferred pressure differential should be for replacing/cleaning the filter.

RE: Air Bleed Valve at Pressure Gage - Required?

14 threads in one year and 12 of those in the first half of the year?

I did say "rather dead" and not rigor mortis.... smile2

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Air Bleed Valve at Pressure Gage - Required?

(OP)
Lol thanks guys for the tips and spirited discussion. It is a smaller scale application and not a true pipeline but hey I figure you guys would know best.

Thanks again!

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