Transfer LPG from one bullet to another

[Filias]

I have to transfer LPG between two bullets. The pump was oversized therefore the operating pressure is below the design point and the flow is too high. What to do to maintain a constant stable flow close to the design working point. I can't add a control valve on the line however the system includes recirculation pipe (spill back) which might return the LPG to the tank.
Thanks,

 

[maddocks]

Short of adding a flow control system (probably the correct choice), try trimming the impeller until the flow meets your requirements. It's a little risky - the other choice would be to flow control the pump spillback but it seems backwards. You could also engineer up a min flow bypass with an orifice to give you the correct flow.

 

[TD2K]

I'm not really clear what your system looks like with this rcycle line. But, another option is to install a VFD on the pump. Not the cheapest solution and you need to make sure that the motor is compatible with a VFD.

 

[danthemeterman]

Filas,
1st, we assume it is liquid propane.
2nd, pump is belt or cface or gear drive.
3rd, size of plumbing and size and type of pump,(PD,centrifigal or compressor). If you tell me pump model, I most likely can give very simple solution. DO NOT BYPASS BACK TO INLET STREAM, especially if you plan on making this a repeatable operation.
4th, what size are the bullets, are they the same size and elevation, and same sun exposure. See where I am going ?
5th, I strongly assume you have ESV's, excess flow and backcheck aperatus in place.