Q&A Forum
Does anybody on here have any experience of pressure reducing valves?
I'm running a 2.2kw 3phase pump to supply water pressure to the load valve, I plumbed in a couple of 1" pressure relief valves (3 bar) which i thought would send the excess pressure back to the main tank and regulate the pressure to 3 bar but the pressure is still up at 6 bar which seems to make the brake over react when trying to do a power test.
I'm thinking of fitting a pressure reducing valve such as:
to regulate the inlet pressure at the load valve, what i was considering is if a 1.5 inch valve would flow enough or if i would be better with a 2 inch valve and reducing down to the load valve.
i would be grateful if anybody could give me any advice
regards
Steve
You are correct that 6 bar is quite high with a 2.2 KW pump. Could you tell me what size plumbing (ID) you have going to the load valve and the length?
I've built up a slightly complicated system as I run quite a variety of engines. I spend quite a lot of time running small 50 to 60 bhp engines but also want the facility to run larger hp when required.
To save a bit of energy I've fitted 2 pumps both 3 phase 415v with the idea that I could run one for smaller bhp and the other/ both for bigger bhp. Both pumps have A 1" BSP outlet so I've used plastic pressure pipe at 32mm od with both pumps joined into a 50mm od plastic pipe which has 2 1" 3 bar pressure relief valves back to the tank at one end and the load valve at the other.
I'm quite surprised at the pressure created given the relief valves, the issue with this pressure is that the load comes on very suddenly given the small hp engines being tested to the point that it is quite easy to stall the engine even on full throttle if the valve is opened too far (25% brake at the end of the run will stall the engine)
Any advice would be appreciated
Regards
Steve
Its definitely a bit of a cluster you have there, but I get why. My suggestion would be to set aside the thoughts of saving a bit of money on power and uncomplicate your life. Since you already have both pumps, plumb them into a large Y connector 2", install a 2" pressure reducing valve after the Y, run your 2" plumbing to your valve, reduce to 1.5" at the valve, (Assuming your valve is 1.5?) keep your lines from the valve to the absorber short. Using large lines will help increase volume and also slightly reduce the pressure, using a large reducing valve will avoid a big pressure drop and help maintain a constant pressure without the pressure valve clattering while constantly opening and closing.
That actually doesn't sound much different from what I actually have so I don't think I'm far away.
I'm using the 1'5" load valve but the inlet to the absorber is 1.25" so reduces after the load valve. I think I can easily add a 2" pressure reducing valve before the load valve to regulate the pressure that is available to the absorber.
The main thing I wasn't sure about was the sizing of the reducing valve but I think I get it now. I will add a 2" valve to my system and see how it goes, if I'm still struggling then I will re plumb it as you have recommended.
Many thanks for your advice
Regards
Steve