Condensate Pump Discharge

[brattong]

Hi all.... Do you know that how to size the condensate pump discharge line (the situation is that the CPD will be pumped back to the boiler in central utility plant with a pressure powered pump)... Are there any charts or tables that can help me find the line size for this CPD??

 

[Keef]

Spirax Sarco have a free technical reference guide entitled Condensate and Flash Steam Recovery which I will gladly send to you. It has a section on sizing condensate discharge lines from both electrical and pressure powered pumps. If you can Email your address to me at keithwoolnough@spiraxsarco.com I will put it in the post.

 

[brattong]

Keef, I think I have the Spirax Sarco reference guide, is it the "Design of Fluid Systems"? I am looking at the Steam utilization reference, on page 51, Figure 50:Condensate Line sizing chart. Is it the one that you were mentioning? I still couldn't see how it can help. For example, I have a PPP to pump back 7200lb/hr (with 125psig operating steam), what should the line size be?

 

[Keef]

Brattong,
No, it is a different guide that I am referring to. Let me know if you would like it.
I can't advise what line size you need as you must find out the head that you must pump against. BUT, for example, if you were using a 2" MFP14 pump (made by Spirax Sarco - but others are available) you would be able to pump this load against a 15 metre head. Depending on the distance you need to pump the condensate, you could go for either a 2" or 3" condensate pipe. However, you need to also take into account whether other traps will be discharging into this line further downstream as this will affect the back pressure on the system. If you are not using the pump to return the condensate directly back into the feedtank, it is recommended that the condensate line allows the condensate to fall by gravity so to prevent potential water hammer problems in the pipework.

Let me know if you need further assistance.