Non-Slam Check Valves vs Butterfly Valve check valve

[ghostface]

I have my experience but there are many very experienced people in this forum
thus want to receive comments.
By natura nozzle check valves have advantages
no adjustment , nearly no maintenance, low pressure, losses, high cv, non slam closure etc.
thus nozzle check valves can be named superior to butterfly check valves with counteer
weight/damper.
Do you have any experience in other way? If cost would be same, for a pump
outlet, would you prefer butterfly check valve for any reason? Thanks in advanced.

 

[LittleInch]

For me it depends on what sort of reverse flow you are looking at.

So e.g. if your pump outlet contains a high amount of static head, then as soon as you pump shuts off you could have reverse flow in a very short time. Then I would want a non slam valve and accept a small amount of reverse flow but avoid pressure shocks.

If the outlet pressure basically slowly reduces as the flow slows and the pressure flattens out then a butterfly valve is fine and normally a lot cheaper.

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

 

[ghostface]

Thanks LitteInch for response as always. Total Diff. head is 20-25 meters.
It is big size but costs are very similar.

 

[LittleInch]

Non slam is always better if you can do it and the cost isn't so bad.

How good it is at non slam is a different matter.... The forces can be huge on the element which is slowing the closure down.

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

 

[Nick_Gray_88]

I’d go with a dual plate check valve, small size good cost, spring loaded so a good response.
With that much water head you could be going for water hammer depending on the exact details of the setup you’ve got there. Plus this is what they were design for…