fire pump installation

[bloudup008]

i am busy with fire pump design (320 l/s @100mWh)

few questions;
-is a R=1.5D miter (5 segments) miter bend acceptable on the suction line (NB 500)? what is the recomended raduis on miter bends?

- what type of NRV is recomended on the pump discharge, double door springloaded type aceptable?

-how can i determine the water hammer efect of this valve, where can i find water hammer parameters of the NRV's?

-is it possible to install butterfly valve on suction when the space do not allow for OS&Y gate valves?

 

[BigInch]

No standards I know about for a miter bend. I would not put it closer than 5 D (preferrably 10D) from the pump flange.

I'd just use a swing check on the discharge, unless its pointed vertically down.

I've never seen any statistics on opening and closing time for check valves. More interesting would be Cv vs position, which I have never seen as well. I have attempted to correlate Cv with velocity hitting a swinging plate, and it doesn't take much V to get it open, so I think time to open depends on how fast you can get some velocity at that point and how fast forward velocity can be reversed. I generally use 0.25 seconds for a small check valve, just because I've got nothing better to say about that.

You could put a butterfly on the suction, as long as its not used for controlling flow. I'd prefer a ball or gate myself for positive shutoff for maintenance purposes.

http://virtualpipeline.spaces.msn.com

 

[JJPellin]

Very good suggestions, Big Inch. Depending on what country you are in, there may be very specific code requirements for fire water pumps. We have extremely strict requirements that dictate pump capacity, piping arrangement, shaft packing (no mechanical seals allowed), annual performance testing and instrumentation. Make sure and check your local governing codes which may specify most of the details.

Johnny Pellin