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View Full Version : Will Sap FLOW THROUGH a Dead Pump (instead of bypass) 4048 question



zandstrafarms
01-17-2019, 01:29 PM
This is regarding a shurflo 4048 vac system on a 3/4 mainline dumping right into a 275 gal tank run by solar and battery.

I understand some pumps totally close when there is no power to them, hence the need for the by-pass valve in the event sap runs during the night. Are there pumps that continue to let liquid through DESPITE not being actively powered on? I know a check valve prevents backflow, and my understanding was that they were one-way. But I am thinking if I mount my 4048 pump vertically, it can drain itself out easily and if sap comes in it won't freeze it up.

If this possible? or does the 4048 not allow ANYTHING through unless it has power? Otherwise I have to look into an electronic valve wired to my temperature controller and battery (suggestions?)

Thanks!

FWIT, I DID call Shurflo and they REFUSED to talk to me since I had NOT yet bought a pump . . . ridiculous customer service!

Chickenman
01-17-2019, 02:00 PM
https://www.entegracoachforum.com/index.php?PHPSESSID=rhqldg59frqkurdfn85upikh1s&action=media;sa=media;in=60

The way I read this I would put in a normally open valve to use as a drain for the inlet side, and the internal valve should drain the discharge side of the pump. I could be wrong, I often am told I am(LOL) but I don't thik I am in this case. The N/O valve should close when your temp controller turns the pump on.

Biz
01-17-2019, 06:40 PM
No sure about the 4048 but the Shurflo 4008 will not flow anything through it when turned off. I have a Seaflo 5.5gpm diaphragm pump that DOES allow a trickle of sap flow when turned off.

The normally Open (N.O.) valve works great as a bypass Valve.

Dave

Super Sapper
01-18-2019, 05:56 AM
Put your pump on it's side with the discharge pointed down and pour some water into the inlet side. I am not sure what kind of check is in the pump but if they are ball checks I would think it should flow through.