High Pressure Recirculation Pump

[Maples Maple]

I am looking to upgrade from 2.5x40 to a 4x40 system (homemade). I currently use a needle valve to re-circ to before the HP pump inlet.

I would like to put a high case (working) pressure pump for recirculation in my system next year. I have looked around but I have not found a great option yet.

Working pressure 250 or 300 psi.
It looks like Goulds has a few options: HM Sleeve pump, 1SV, or 5GB
Do the Procon pumps work? I only see the outlet pressure and not the case pressure.

If you have 4x40 system, what high pressure re-circ pump are you using or is in your system? MES, CLD, homemade, etc.

Thanks

[maple flats]

If you run from just before the needle valve back to the high pressure in port, I think a pump of low pressure will do fine. Why do you feel you need high pressure for that?
You get recirculation now with no pump other than the one high pressure pump, a normal or low pressure pump will increase that flow considerably without being high pressure on the recirculate portion in my thinking.

[Maples Maple]

My understanding is that pumping at HP with very low delta P creates less heat, is more efficient and more flow over the membranes than dropping it down in pressure to bring it back up. All of that with added complexity and expense of an extra pump/tees/backflow preventers/etc.

I currently have a needle valve to recirc to low pressure side of the pump but as I am looking to move up in size I thought I would look into options for making improvements in the system.
I sent you a message about your 4x40 housings. Are they still available? Do you still have the MES membranes?

Thanks
M

[maple flats]

Who are you asking about the housings? I didn't get any messages from you. If that was for me, I sold the new membranes with the RO, I do have 2 4x40 SS housings rated for 300 psi. Email dave@cnymaple.com if interested.