Pump Recirculation Piping - Best Practice

[mark1131]

When we pipe up our PD pumps (sliding vane) it is normal practice to provide a mechanical bypass valve and manual bypass valve at the discharge to account for any accidental pump dead-heading or to reduce process flow. This bypass/recirc line is almost always piped back to our supply tank. I was wondering if there were any major issues with piping that line back to the inlet of the pump instead of the tank. Our main process fluid that I am concerned with is anhydrous ammonia. Thank you.

 

[Latexman]

Yes, the mass of fluid in the piping is much, much less than in the tank, so it will heat up much, much faster when recirculating. Vapor lock and cavitation issues come to mind.

Good luck,
Latexman

 

[BigInch]

For future reference, post these type questions in the pump forum.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[mark1131]

Ok, will do. Thanks for the help.