Sluice gate design head

[PersianEng]

An sluice gate is operating on a pipe with maximum pressures due to an upstream pump of 50 psi and discharges to an open top tank of 10ft depth. On the other hand since the gate is to contol the flow to the tank and the tank level it may not be fully open sometimes and will see flow presure behind it. Now the questions are:

1) Whether I should consider the design head of sluice gate as 115 ft (50 psi line pressure)or not.

2) If the answer to the first question is "yes", is it cosidered very unusual to operate a sluice gate against 115ft of head.


Thanks.

 

[Ashereng]

Ans to Q1)

In this case, the maximum differential pressure is 50 psi.

So, you need an actuator that can open/close against this pressure, otherwise, your valve may not work. (Include safety margin.)

Where you normally operate doesn't matter, it is the maximum of all conditions you need to account/size for.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[stanier]

Sluice valves generally have a bypass valve installed to allow the pressure either side to be balnced so it can be opened.

Geoffrey D Stone FIMechE C.Eng;FIEust CP Eng

http://www.waterhammer.bigblog.com.au

 

[PersianEng]

I don't agree stainer. Unless the bypass is comparable in size to the gate, what does the bypass valve can do if the pump is continuously discharging upstream of the gate?

 

[PersianEng]

For those of you who were following this thread, here is finally what we did:

We replaced the gate with a butterfly valve since sluice gates are not suitable for high differential head applications. Although one of our senior engineers said that he recalls very old installations of sluice gates to open under several hundred feets of water in dam applications operated by hydraulic cylinders but these have been of very rugged special design, not economical to todays engineering with better solutions in hand.

Thanks for your contributions in discussing the matter.

Majid

 

[leecoop]

PersianEng,

Hydraulic cylinders can be very inexpensive compared to other solutions.