Valve flow testing suggestions?

[NaterC]

I'm a new engineer for a small LPG/NH3 gas connections company. I've been tasked with developing a battle plan for a new flow test bench for our various lines of valves and connectors. We make a lot of filler valves, globe & angle valves, safety relief valves, etc from less than an inch on up to 3" inlet/outlets.

The whole point of being able to flow test is so that we can get an idea on the performance of our valves before sending them off for U.L. approval, and most importantly, before they're released for production. We'd like to have it in house to avoid the costs of sending them out to be tested, along with avoiding having to re-submit to U.L. and the like.

I figure my first step is to choose a pump, so lets start there. The envelope I'm looking at is hopefully to be able to hit 200 PSI and 300 GPM+, but not necessarily at the same time.

Any suggestions? I've looked at some pumps from Blackmer, I figure they're the real world use pumps that our products work with, they would be ideal to use in flow testing right?

All help is much appreciated,


Nathan

 

[MikeHalloran]

What's the purpose of the flow test?

E.g. if you just want to know the valve's Cv, you don't have to test it over its entire operating range, or at its highest flow rate.

If water is okay as a test fluid, a sprinkler pump recirculating into a tank, a pressure gage, a bucket and a watch would comprise a basic but sufficient test rig.



Mike Halloran
Pembroke Pines, FL, USA

 

[NaterC]

First off I guess I should mention that the valve of interest is a bypass valve, but we'll also be testing a multitude of globe & angle valves in various sizes, filler valves, etc, etc.

The reason for the test is to see if the valve is opening at the correct pressure rating(meaning the spring setpoint), and to get an idea of what the flow rate is going to be after it opens.

Bosses want it for marketing obviously, and engineering wants it to see how we stack up to the competition.

 

[MikeHalloran]

I'm guessing that there are standard test procedures within the trades into which you sell, so the logical thing to do is tool up to conduct those tests as written.

If you're doing it as a tool to show off, you want all the pieces nice and shiny, or at least clean. If you're intending to do comparisons, e.g. with competitive equipment, it would make sense to build a double test stand, so you can actually conduct two tests simultaneously.



Mike Halloran
Pembroke Pines, FL, USA

 

[gerhardl]

We are talking about a fairly large volume here, and some factors obviously have to be taken into consideration and decided upon during the planning periode:

- General safety if valves should burst
- For this purpose water better than gases/air
- Caretaking of outlet from safety valves
- Flow or only pressure checks?
- If flow checks: pumps will probably not be exact enough on pressure and amount. Good quality regulating valves with large control span for capacity and pressure variations will probably have to be installed in the circuit. Also perhaps pressurized vessels or general reservoir?
- Single test-station or several or a multitude of valves tested and resulting influence on pressure regulating and lay-out before and after valves?
- All pumps, measurement instruments, regulating valves and other itmes of quality to be calibrated, certified and give result within acceptable accuracy limits over the wished for time.
- Room enough on rig for straight stretches and alterations, modifications and additions and maintenance in the future.

 

[itascot]

Try the attachment, could prove helpfull.

Ciao,

 

[JimCasey]

No point in reinventing the wheel..
Groth Equipment and Calder Testers are two makers of test stands and both are in Houston. I googled "valve test stands" and got the typical 667000 hits in 20msec.

Both of the companies I mentioned have been around long enough to refine their designs and to include features that might not be readily apparent if you have not used a tester and want to design your own. And no, I am not affiliated with either, although I have experience with both.

 

[ajdowdell]

How long duration are you wanting to hit those flows? Air or water? I'm thinking you're going to want large storage tanks and compressed air storage. 200 psi should be no big deal you can buy tanks for that all day long. you could get away with a smaller pump let it run over night then discharge your tanks during the day (if necassary run pumps all day too, jsut watch for the pressure spikes)