Best way to divert very high pressure/volume hydraulic flow?

[bricol]

Agreed and that would probably be the best solution long term, with a view to automating it by swapping out the ball valves for solenoid valves

If speed of response isn't that important, just use air operated ball valves. Easy to get hold of, reliable, and easily serviceable if needed.

 

[Fred Trevvett]

If speed of response isn't that important, just use air operated ball valves. Easy to get hold of, reliable, and easily serviceable if needed.

Thanks, that sounds like a good option. Means having to pipe compressed air out to the yard though but that's not a huge issue

 

[Pete.]

You absoluely must have a pressure relief valve to vent around the pump.

The old high pressure dump guns didn't have any pressure relief valves but they did have bursting discs. The relief valve was equal to the operator's hand grip on the dump trigger.

 

[carbon]

Danfoss make some solenoid valves for use with high pressure water. With a flow rate of 120lpm it seems like 3/4" is the most suitable but has a pressure limit of 140 bar rather than 150 bar.

Part no: VDHT 3/4 EA NC BSP N on the following pdf link

Danfoss Valves

 

[8ob]

The old high pressure dump guns didn't have any pressure relief valves but they did have bursting discs. The relief valve was equal to the operator's hand grip on the dump trigger.

I was wondering if there was a way to get it to recirculate on trigger release rather than
beat on a pressure relief valve.

Bob

 

[Pete.]

I was wondering if there was a way to get it to recirculate on trigger release rather than
beat on a pressure relief valve.

Bob

Well a dump gun just does what it says, dumps the water out of a 1/2" tube on the floor instead of firing it at 16kPSI through a 2mm jet but there's nothing to prevent you piping it back to a tank I guess.

 

[carbon]

I was wondering if there was a way to get it to recirculate on trigger release rather than
beat on a pressure relief valve.

There are some serious large unloader valves available for pressure washer application than would cope with the specs provided with ease but they dont usually come cheap.

 

[carbon]

Well a dump gun just does what it says, dumps the water out of a 1/2" tube on the floor instead of firing it at 16kPSI through a 2mm jet but there's nothing to prevent you piping it back to a tank I guess.

Ive not had a lot to do with dump guns but have seen them used with large jetters that dont have unloader valves fitted like the harben ones. If you have the appropriate unloader valve fitted it just returns low pressure water back to the pump inlet or better still the water supply tank for better pump life.

 

[Anguz]

If the 3 pumps are connected to the same manifold, and one relief valve opens slightly before the others, does that attempt to take full flow of all 3?

 

[Bornfree]

If the 3 pumps are connected to the same manifold, and one relief valve opens slightly before the others, does that attempt to take full flow of all 3?

On the Kew multi pump system we had. It had 6x 11kw pumps all running into a common unloader valve.

 

[Anguz]

On the Kew multi pump system we had. It had 6x 11kw pumps all running into a common unloader valve.

But that would have been a larger valve? The one on a single pump is surely designed for 1 pump

 

[carbon]

But that would have been a larger valve? The one on a single pump is surely designed for 1 pump

Usually the unloader valve that is matched with a pump from a manufacturer is of similar specifications to the pump as theres no need to fit anything bigger. But some uloader valves may be rated at twice the specifications of the pump it really just depends on the manufacturer. With a pump that is rated at 120 bar 120 l/m its more likely that the unloader valve will be of a similar specification. A pump that is rated at 100 bar 12 l/m can have an unloader fitted that is rated to 210 bar 40 l/m, because of the wide range of adjustment of the unloader valve. It does get a bit more complicated if the unloader valve is flow sensitve as the flow rate has to be matched more closely to the pump.

 

[Bornfree]

But that would have been a larger valve? The one on a single pump is surely designed for 1 pump

Yes it was huge 1" or 1 1/4"

 

[Turbo]

On the Kew multi pump system we had. It had 6x 11kw pumps all running into a common unloader valve.

I used to service one of those & it was a very clever setup, The downside was you had to service it at least every 700 hours & the parts weren't cheap! If you needed to replace the unloader valve it was a very expensive option!

I would suggest looking at suttner for a bypass valve, they are top quality German made & do valves for all pressures & flow rates. They also do a good range of other flow control equipment.

Forget about using hydraulic gear as it will rust very quickly unless you go for stainless steel stuff.