Check Valva Bilge Pump

[Alaskan Sea-Duction]

I am replacing one of my bilge pumps. Last winter I had check valves installed on 2 of my pumps spaced about 5 inches from the pump output.

The instructions with the 2000 Rule automatic pump says NOT to install a check valve. Without one I get about a quart of water back into the bilge.

What say you?

 

[Comodave]

I just live with the water. It is pretty easy for some debris to jamb the check valves anyway. We had a Whale Gulper as a stripper pump in a previous boat that had a built in check valve that worked well. But it was pricey.

 

[vacser]

I have check valves on all my pumps for the same reason. No problems

 

[Ken E.]

I used a check valve on my center bilge pump, the lowest point in the boat and the primary pump. I have subsequently removed it, and I just tolerate the water back-draining. I removed it because it seemed to interfere with the prime of the pump, sometimes but not always, when I did periodic tests of the pump and float switch. No such problem with the check valve removed.

 

[dhays]

A check valve has the potential for creating a problem that given the right combination of unlikely circumstances could be disastrous.


I'd live with the water. If there is one location that always has that last bit of water, you can install another small pump and sensor just for that. It won't replace your primary bilge pump but can handle the last bit that your other pumps leave behind.

 

[Comodave]

I found this online, I have no experience with it or affiliation. The price was around $150.00.

 

[deblen]

Some things to consider : / Len


Resist Using Check Valves

 

[Ken E.]

Some things to consider : / Len


Resist Using Check Valves

+1. Excellent summary.

 

[rslifkin]

A check valve on one small pump at the lowest point to keep the bilge dry is fine. Or use a diaphragm pump for that purpose, as they have no backflow naturally. But absolutely no check valves on any bilge pump you rely on to work and care how much water it moves.



Personally, I live with the quart of back-flow even on my maintenance pump, as it serves the function of back-flushing the intake strainer on the pump in case any crud gets in there. Then I can just clean the crud out of the bilge when I see it. With a check valve and no back-flow, it's more likely to end up clogging the strainer.

 

[HopCar]

I wouldn’t worry about a quart of water. If it bothers you get a Rule low profile pump. They have joker valves like you find on a marine toilet. The draw back is they only pump about 900 gph.
https://www.amazon.com/Rule-LP900S-...ocphy=9011924&hvtargid=pla-302099030292&psc=1

 

[rslifkin]

FWIW, I tested one of the similar low profile Whale Supersub pumps both with and without the included joker valve type check valve. It definitely moves quite a bit more water without the valve. I kept the valve removed as I found it would occasionally airlock and need to be wiggled a bit before it would prime if it had sucked the water level down too low on the last run. I had a similar issue with one of the newer oval Rules with the joker style check valve as well.

 

[HopCar]

FWIW, I tested one of the similar low profile Whale Supersub pumps both with and without the included joker valve type check valve. It definitely moves quite a bit more water without the valve. I kept the valve removed as I found it would occasionally airlock and need to be wiggled a bit before it would prime if it had sucked the water level down too low on the last run. I had a similar issue with one of the newer oval Rules with the joker style check valve as well.

The Rule copy of the Whale allows you to rotate the discharge to a vertical position which should prevent airlock.

 

[Russell Clifton]

You can buy Rule bilge pumps now with a check valve built into the pump. I installed one for my shower sump two years ago with no issues thus far.

 

[rslifkin]

The Rule copy of the Whale allows you to rotate the discharge to a vertical position which should prevent airlock.

The whale has the discharge pointing up as well. What I found was that if the pump was drained, it couldn't refill far enough to push the rest of the air past the check valve. The built in bleed hole wasn't enough to purge it unless I wiggled the pump a bit. Without the check valve, it primed reliably.

 

[O C Diver]

I have a check valve on each Rule 2000 and am very happy with the results. Each Rule 2000 is backed up by a Rule 3700 that's mounted 2" higher and without a check valve. While I'm comfortable with a check valve on the pump, I think having a backup is also a good plan.

Ted