Manual Valve Closing Times
Manual Valve Closing Times
(OP)
My Friends,
I am working on a project which has many large gear operated valves.
Is there any standard or reference on how long it takes to open valves of different sizes and types, standard gearing ratios, etc? Any help is appreciated.
best wishes,
sshep
I am working on a project which has many large gear operated valves.
Is there any standard or reference on how long it takes to open valves of different sizes and types, standard gearing ratios, etc? Any help is appreciated.
best wishes,
sshep





RE: Manual Valve Closing Times
David Simpson, PE
MuleShoe Engineering
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RE: Manual Valve Closing Times
Google water hammer and do your research on the opening/closing time for valves.
As far as large manual, geared valves concerns, how long is the piece of string? How fast can you spin the handwheel? Typically, these valves are much slower than the actuated ones, so I wouldn't worry too much on the closing time. You can get these time figures from the valve supplier or you can work with him to determine the actuating time.
Cheers,
gr2vessels
RE: Manual Valve Closing Times
My immediate case was to answer how long it would take to fully open 20" manual gate valves, which I anticipate will be gear operated. I know from my own experience that it can be tiring- i.e. the gearing is usually that it turns easily, but that it takes many many turns. I guess I tire easily because if there were more than one or two big valves, we usually did it as a team so that there was a chance to rest. In this particular case the valves must be opened on an emergency basis. They will have at least 45-60 minutes notice, but not all of this time will be spent spinning the valves- i.e. travel time and other actions. This is where the question came from.
Anyway, thanks for the advice so far.
best wishes,
sshep
RE: Manual Valve Closing Times
Is it an "emergency" action to open? Or to shut?
What happens if they don't open/don't shut? (Fire continues? Lube oil is not supplied from alternate tank? Nerve gas keeps leaking? Oil keeps flowing into river? )
Are you manned 24 x 7 with a truck available? What happens if the crew can't get there? If only one person is available? How long does it take to get to the platform or the staging to turn the valve?
.... So any or all of those would be reasons to put in an automatic valve or a remote-controlled valve operator.
Why not? Expense of purchase, install, maintain, test, backup power, actuating power, etc.
RE: Manual Valve Closing Times
RE: Manual Valve Closing Times
RE: Manual Valve Closing Times
If you try to shift a valve which hasn't been opened for a long time though, forget the free wheeling bit.
So, you need to get the valve suppliers data sheet for his manual actuator for your particualr valve(s) and find out how many revolutions it takes to open / close and then guess a bit as to how long each revolution of the hand wheel would take - for a 12 to 16" one, my estimate would be about 5 seconds per revolution for an easy well maintained valve and 10 seconds for a worst case.
If its a lever operated vlve then it's about 2 seconds open to close....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Manual Valve Closing Times
RE: Manual Valve Closing Times