Reduce static Pressure

Not much to go on here - a diagram or schematic would be useful.

Any type of control valve (globe, plug and cage or even maybe plug valve) can be opened slowly to control initial flow.

How is the operator being exposed to flow?

Assuming you mean water, yes 30 bar can be dangerous, but look at your post and ask how is anyone supposed to understand anything about the operation, location, size, end fittings, type of valve etc?



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Sorry for the poor information, i didnt want to complicate the question with many variables.

its suppose to be a system to clean chute of transfer in the mining, so I need high pressure , but the end of the pipe should be connected with a hose, so the operator can clean the chute.

This is the hydraulic profile for a 4" pipe, where at the top is connected with a Tank.

As you can see the blue line represent the static pressure when the system is not being used.



So how can I control this huge pressure? sure can I slowly open a valve, that will represent a instant energy loss, but it will be dangerous for the operator.

Your first post says 300m of static - you are now saying 3000+ m - what is it?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

Artisi - read the graph - It's elevation. He's going from 3,300m (quite a long way up) to 3000m.

If you size your control valve right then it shouldn't be a big issue.

You might need a plug and cage type valve to handle the pressure. Either that or a pressure regulating valve located upstream of the last valve which shuts off tight at say 5 bar and controls the downstream pressure to 5 bar. 5 bar is enough to create a serious jet.

These pressure might seem huge to you, but in reality are low to medium pressures for a lot of other applications.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

gugovod,

I think LttleInch is right. Your best bet is a Pressure Regulating Valve which will control downstream pressure ~5-7 barg. I wouldn't go higher than that. Some of local plumbing codes limit potable water pressure to 5.5 barg because of safety reasons.

300 m of water column is 1000 ft head = 422 psig = 29 barg. I wouldn't want to be a person opening a valve in the end of this line!