Common Operations Practice: Actuated Gate Valve Stroke Time

[ZDawg]

Good morning all. I have looked everywhere and found nothing apart from resources to calculate specific times for actuators and warnings when doing so to determine the closing time for an actuated gate valve.

I am trying to find notes from people either in operation or those that work with them to determine what a common practice is for closing times on a gate valve for a pipeline. I've seen 1s per 1" OD, I've heard 60s per 12" OD, but both of these were one offs.

The reason I'm asking is the last project I worked on, the stroke times varied per pipeline (understandable) but operations had some complaints to the time it took for most of them. On a new project we've been tasked by the client to provide estimated stroke times that we can give to the manufacturer to see if they can meet those times or do better (last time we just went with what the manufacturer suggested which was obviously slow because it's easier for them to do).

Any kind of input helps. This is for a 30" oil pipeline and we're only providing estimates to the client, who will then convene with operations and deal with the valve/actuator acquisition.

 

[LittleInch]

Well the default closure speed, even for ESD valves seems to be 1 second per inch as an initial start point, then work it out from there.

I had an 18" spring return high pressure valve which closed in 4 seconds - made the spring pretty big, but the actuator manufacturer was able for it.

A lot depends on size, no of times it opens and closes, power supply for your actuator ( air, hydraulics, elec).

For a 30" high pressure valve I would expect 5 minutes for manual operation ( say 100-150 turns of the wheel), less than 60 seconds for an actuated valve of any power source.

But I wouldn't listen to operations too much - they would complain if it opened too fast, or impacted some other part of the unit. The issue is CAPEX and the size of your airline or power supply. Chop that in half and you will easily pay for several days/weeks of operations time waiting for the valve to close....

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

 

[ZDawg]

Thank you for the info. 60 seconds for a 30" valve is much faster than they were talking about in the last meeting I had. They had mentioned some of the older projects were done with stroke times of 230 seconds. If we can get them to go to the manufacturer with even half that, it shouldn't be a problem then and they can work to narrow that down later.