Pros/cons different valve types for ESV

[Kreot]

This must be the perfect place to ask this question as i see a lot of experience among the users.
What are the experience(pros&cons) with the different types of valves for emergency shut down? ( ball, gate (slab, expanding))

Thanks

 

[gerhardl]

Stiaf,

As for all other valves: depends entirely on application: (size. fluid, pressure, flow, temperature, size and requirements for closing time). It is more about finding a dependable tested combination of actuating release device and valve in combination, combined with a quality (and cost necessary to avoid serious consequences if failing.

If you could describe the application you have in mind, I am sure you would get more pointed opinions.

 

[bcd]

For ESD valve, best choice is to use the valve type you know through experience works well in the process. Emergency shut-down is not a good time to find out the unproven valve design is not suitable or compatible with the process conditions. If historically you have successfully used a certain brand and type of ball, butterfly, globe, etc. valve in the process, then you should consider using the same for ESD.

 

[pennpiper]

stiaf,
gerhardl has given you the correct answer. If you expected more there is much you did not tell us.
1. Is this "a Specific Question" or "a General Question"?
2. If it is a Specific Question then then we need more detail.
a. What is the Service (Liquid or Gas, Commodity, Operating Pressure and Temperature)?
b. What is the line size?
c. What is the nature of the Emergency?
d. How fast should the Shut-Down be?
e. If the commodity is Liquid and the shut-down is required to be fast how would you handle the "Water Hammer" effect?

3. If you are asking "a General Question" about ESV then the answer might be, any valve can be used.

Sometimes its possible to do all the right things and still get bad results

 

[LittleInch]

For ESD you want simple proven technology with high reliability at lowest cost.

It's difficult to go away from simple quarter turn ball valves fitted with a spring return ( or open) scotch yoke actuator.

Tens of thousands in use worldwide.

Other types - Sure they are possible, but tend to be bulky and difficult to fit the actuator (gate valves) and just not very common ( plug valves etc)

YOu don't use ESD for any other purpose, so wear shouldn't be an issue and in most places some level of leakage is acceptable as you've shut off 99%+ of the flow.

If you really really want it to seal tight then an expanding gate is probably your best bet, but every more complex operation adds to the uncertainty and cost.

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

 

[gerhardl]

Just to comment on the vast range of the 'ESD' types.

For instance: Double eccentric ball or double eccentric BFL valves with oil hydraulic lifted counterweight with diameter up to one meter and more, counterweights at several tons, for water mains with high pressure or hydro-electric power plants.

Also for high pressure steam at up to 500 deg C there are cases where other types than ball-valves are preferred.