Small pilot operated valves

[Zoobie]

Does anyone know of relief valve manufacturer that makes small pilot operated valves? I am specifically looking for 3/4 x 1 valves that meet ASME code. Farris, Consolidated, & AGCO don't make a pilot operated valve below a 1x2. I am looking at a lot of piping modifications to accomodate the larger valves...they are quite a bit heavier.

 

[TSeener]

Zoobie,

What's the application? (Process, Steam, chilled water, etc)? Standard question, right?

Now, I would typically use a series 2700 by Farris, which is an ASME code rated valve, and it comes as small as 1/2" screwed. I have also purchased them as 3/4" x 1" flanged. I have also seen that you can get Kunkle in sizes down to 1/2" screwed, but they are material of construction dependent (the application question).

Hope that this is of some help.

Best Regards,

TSeener

 

[Zoobie]

Service is natural gas. The 2700 does not appear to be a pilot operated valve. The website does say however that it comes in a balanced design. How does this compare to a pilot operated valve? We are trying to take advantage of operating at 95% of set pressure as opposed to 90% which we do not exceed with the conventional valves installed.

 

[TSeener]

Zoobie,
My mistake on the pilot for the gas service, I suggested it because I thought that it might pass, but given the natural gas....

However, what is the desire for the piloted relief? Bubble tight shut off and the ability to run very close to the systems set pressure (i.e. 95%)? Then there is the small size, which leads me to believe that your looking at small flows and perhaps a higher pressure (greater than 500 psig)... All assumptions here...

I went back and looked at the 2700, and the balanced design does offer some things that I had always found very attractive. It can be factory set to reseat at 5% of set pressure, and it can withstand a variable back pressure on the relief line.

It still may not be exactly what your looking for here... Sorry I couldn't be of more help... I'll look around and see if there is something else out there...

Best Regards,

TSeener

 

[heightandlight]

Hi I am in the Uk and have just brought a hook lift tipper truck(dumper) it is supposed to dump 4 tonnes but wont even begin to lift with 1/4 tonne load.

I have re-sealed the hydraulic ram and checked the spool valves and pump which runs from the gearbox.

On load testing the ram we found that initially when lifting it was just under 1 tonne when starting to lift which increased to 4 tonnes when half extended.

What I would like to know is would the pressure relief valves cause this kind of fault?

 

[TSeener]

Hi,

The pressure relief valve could be blowing by, but it almost sounds as if there is an air bubble in your hydraulic system. If you see any jerky movement in it's operation, that is a good indication.

The pressure relief valve as you posed the question, could be causing the issue, if they are leaking by under pressure, or were not sized for the intended load, so they are releiving at too low of a pressure.

Best Regards,

TSeener


Zoobie,
I have had much of a chance, but you should speak to your local Farris vendor (Flowserve), and they should be able to give you the specific limitations of their series.

Best Regards,

TSeener