Bilge Pumps

[coopec43]

I am currently installing X3 bilge pumps. (Rule 2000 x2 and Rule 3700 x1)

The discharge outlet for the main pump is about 2ft 6in. above the WL. If I don't put an anti siphon loop in then in a choppy sea water would flow into the bilge every-time a wave covered the outlet.

As a result I have removed a crockery cabinet in the galley so I can install the anti siphon loop up into the cabinet, across the top of the cabinet (just under the deck) and then back down to the outlet.

My questions:
1. Rule Pumps are quite definite that back-flow preventers (check valve) should not be used but now I notice an advertisement for a Rule 1100GPH which states:

Backflow prevention - now includes a removable check valve in the discharge nozzle which reduces the amount of water draining back from the pump discharge hose into the bilge. Please note - using the check valve will reduce the rated output flow."

Have Rule Pumps finally have a change of heart? Why can't I use one on my larger pumps?

2. Why can't I use a ball valve attached to the skin fitting outlet as I cannot see how they could possibly restrict the flow? (I suppose you'd have to leave them open if the boat was unattended)

Would appreciate your comments

Clive

[Lepke]

Bilge debris eventually gets in the check valve holding it open. If you don't have an anti-siphon loop... you know the rest.
Look in the ball valve to see if it's hole is the same size as the pipe diameter. Usually they're smaller and restrict flow. Ball valves that don't restrict flow have bigger middle to allow for a larger ball and ball hole.
I have a new Rule with the rubber check valve installed in a shower sump after a fine screen. It only took a couple days for it to leak back. I have a deep bilge and about 6' of hose to the loop and was hoping to use a smaller sump. But it leaks back and the too small sump fills enough to trigger the float. So every 15 minutes or so you hear the pump come on for a second. Great product, probably made in China.

[coopec43]

Originally Posted by Lepke

Bilge debris eventually gets in the check valve holding it open. If you don't have an anti-siphon loop... you know the rest.
Look in the ball valve to see if it's hole is the same size as the pipe diameter. Usually they're smaller and restrict flow. Ball valves that don't restrict flow have bigger middle to allow for a larger ball and ball hole.
I have a new Rule with the rubber check valve installed in a shower sump after a fine screen. It only took a couple days for it to leak back. I have a deep bilge and about 6' of hose to the loop and was hoping to use a smaller sump. But it leaks back and the too small sump fills enough to trigger the float. So every 15 minutes or so you hear the pump come on for a second. Great product, probably made in China.

I have made up ply lids for my sumps - that only took a couple of hours but maybe I should put fly-screen as well velcroed (hook and loop) to the hull? I know for a fact my bilges get debris in them but of course I am building.
(I imagine your shower sump would collect body hair)

Clive

[Terra Nova]

Never install check valves in bilge pump lines.

Use a diaphragm pump to dry the bilge.

[SV_Harbinger]

Never use check valves on a bilge pump line, they don't work ( maybe at first, but they fail with remarkable certainty) an anti-siphon loop is a much better way to go. On the other hand I like the multiple pump plan but I would put a manual diaphragm in there somewhere as well.
I have a Rule Mate 500 (for automatic pump operation) an Attwood T800 (manual on and off) and Seaflow manual diaphragm pump tucked away in the hanging locker and rigged to take a suction on the bilge. I have another pump in the shower sump but apart from being a Rule product I don't remember what model it is or what it's flow rate is....

[coopec43]

Originally Posted by SV_Harbinger

Never use check valves on a bilge pump line, they don't work ( maybe at first, but they fail with remarkable certainty) an anti-siphon loop is a much better way to go. On the other hand I like the multiple pump plan but I would put a manual diaphragm in there somewhere as well.
I have a Rule Mate 500 (for automatic pump operation) an Attwood T800 (manual on and off) and Seaflow manual diaphragm pump tucked away in the hanging locker and rigged to take a suction on the bilge. I have another pump in the shower sump but apart from being a Rule product I don't remember what model it is or what it's flow rate is....

OK you've convinced me even though Rule now sell their range up to 1100 GPH with check valves.

I will install my bilge pumps and switches approx 6 inches above the bottom of each bilge (approx 12 inch X 18 inch). That way when the water does flow back into the bilge it won't trigger the switch.

I have been using a small TMC (cheap) bilge pump to pump the last remaining bilge water but it leaves about ¼ inch before sucking air. I will now install diaphragm pump(s) as you have done. Maybe like the one pictured?

Thanks

Clive

[SV_Harbinger]

I was thinking something more like this, far more useful if the electrics go the way of the dodo. And unless your boat is very large it shouldn't take too many strokes to get the bilge down enough if you want to work on something down there. Mine is typically only used a couple times a year when I do a bilge cleaning the rest of the time I let the Rule handle it.

[J.Kitchens]

Originally Posted by SV_Harbinger

I was thinking something more like this, far more useful if the electrics go the way of the dodo. And unless your boat is very large it shouldn't take too many strokes to get the bilge down enough if you want to work on something down there. Mine is typically only used a couple times a year when I do a bilge cleaning the rest of the time I let the Rule handle it.

+1

Gotta have a manual diaphragm pump. I'd be perfectly happy giving up any other mechanical device; not my Whale Gusher....or my windvane.