cla-val 990 PRV operating outside labeled adjustment range?

[CrazyHorse81]

We just installed at PRV Station #2 a 1-1/2" direct acting pressure reducing valve with a label of 80-140 psi on it - that caught my attention because I needed the other one with an adjustment range of 30-90 psi as my outlet pressure required is 40 psi.

This put me in a bit of a panic, so I ran down to the site and took the up and downstream pressures of the PRV. The gauge recorded 81 and 40 psi, respectively.

Unfortunately, I cannot get a flow measurement through the valve, but I could not hear the flow going thru (unlike the other PRV Stations that sometimes roar). I have a tech rep coming in June to look, but there is no way to tell what's in the valve because it is one piece. He said that you have the correct valve but mislabeled if the downstream pressure remains 40 psi in static conditions. He said that this valve should not work anyway because it is outside the adjustment range. ???

Has anyone experienced this before and what did you find out?

 

[bimr]

You probably should get the shop drawings and contact the manufacturer to determine what is actually installed.

 

[hydrae]

Sometimes there is a weep hole in the bell (spring chamber) of the valve, Cla-valve uses different color paint on each spring to state the rate. If you can see the spring through the hole and find the color, check with your local rep for the rate chart.

It is possible to adjust a higher spring rate to a lower setpoint, it is just not very accurate.

Hydrae

 

[CrazyHorse81]

bimr: I didn't disclose that in my post, but we have a clause in the contract that if the contractor doesn't submit shop drawings for approval to the engineer that they assume responsibility for installing the specified product...so, unfortunately there are no shop drawings on record for what was installed.

hydrae: I will check that out. I did notice that the pilot operated valves have different colors for different rated springs as you are saying.