Non Slam Check Valve

[peter vaf]

"Dear Check Valve Expert,

I have a question about the 'Non-Slam Check Valve.' What are the differences between the two types of check valves?

Additionally, is it practical to manufacture a WAFER Type Non-Slam Check Valve with a size of 36", or is it only possible to manufacture the flange type?

 

[Danlap]

Hello,

Not being "check valve" expert, but both indeed categorized as Non-Slam. Having both types installed on my site, IMO it is more whether small (down to micro) cracking pressure and relatively small Differential Pressure are required or not. If yes, then it would be the bottom one.

What sort of temperature, product and mounting position?
Having 20"-2500# - flange - installed 100 meter above ground on vertical piping, it would require us to rent the 2nd largest mobile crane in Netherlands for 5 yearly maintenance and inspection. It is a challenge for sure.
Things such as but not limited to:
- Bolt relaxation.
- Gasket used
- Alignment
- Effect on flow characteristic throughout the 'nozzle'. this need to be asked to the manufacturer
- Maintenance strategy
- etc.

One thing almost for sure, once wafer type installed then you will depending on that manufacturer through end of its lifetime as most likely it would be manufacturer's design specific.
PS: manufacturer can go bankrupt and/or acquired by different company, hence my comment.
I am pro for flange type.

Kind regards,
Danlap

 

[peter vaf]

Dear Danlap,

Thank you so much for your explanation. I have grasped all the points I needed from your perspective.

Best regards,
Peter