Non return valve for a Rule bilge pump

[Ubergeekian]

Jumblie has a Rule automatic bilgepump. It's down in the bilge sump, which is about 3' below the discharge point. Three feet of 3/4" tube contains almost enough water to fill the sump enough to trigger the pump, so it tends to short-cycle.

Is there any reason why I shouldn't fit a non return valve next to the pump in the discharge hose ... and if so, can anyone recommend a suitable valve?

 

[mikefleetwood]

Feed it through a hand pump. Useful standby in case the electric fails, and includes a non-return valve.

 

[KenMcCulloch]

Jumblie has a Rule automatic bilgepump. It's down in the bilge sump, which is about 3' below the discharge point. Three feet of 3/4" tube contains almost enough water to fill the sump enough to trigger the pump, so it tends to short-cycle.

Is there any reason why I shouldn't fit a non return valve next to the pump in the discharge hose ... and if so, can anyone recommend a suitable valve?

I tried fitting a n/r valve in mine for the same reason but the centrifugal Rule pump won't reliably self-prime against the extra resistance. Adjust the mounting of the float swith if that's what you are using.

 

[Tranona]

I have a non-return valve in mine and it works fine. Pretty sure it is a Jabsco part There is a check valve listed in the Rule accessories, but no image on the web to see if it is the same thing.

 

[VicS]

This has cropped up on the forums before. IIRC there is some objection to fitting a check valve but I cannot remember what it was.

Would a check valve in the pump suction be the solution. It'd stop the water draining back when the pump stops and also maintain the prime.

But if you are talking about a submersible pump my suggestion is not applicable. Perhaps it wont lose its prime anyway if its submerged.

 

[Ubergeekian]

Feed it through a hand pump. Useful standby in case the electric fails, and includes a non-return valve.

The electric pump is the standby - there's a honking big Whale manual pump as well!

I tried fitting a n/r valve in mine for the same reason but the centrifugal Rule pump won't reliably self-prime against the extra resistance. Adjust the mounting of the float swith if that's what you are using.

But if you are talking about a submersible pump my suggestion is not applicable. Perhaps it wont lose its prime anyway if its submerged.

Sorry both, I wasn't clear. It's a submersible pump with integral float switch. Fitting a separate switch would be a real pain - it's all got to go in a sump about 2' long by 5" wide by 18" deep directly below the engine, and it has to share the space with the inlet pipe and strum box for the honking great Whale pump previously referred too.

I have a non-return valve in mine and it works fine. Pretty sure it is a Jabsco part There is a check valve listed in the Rule accessories, but no image on the web to see if it is the same thing.

Thanks. I shall investigate, and perhaps do some experiments.

 

[prv]

Fitting a separate switch would be a real pain - it's all got to go in a sump about 2' long by 5" wide by 18" deep directly below the engine, and it has to share the space with the inlet pipe and strum box for the honking great Whale pump previously referred too.

Obviously you'll be wanting to keep the submersible you already have, but for the record I solved this problem by using a motorised diaphragm pump. KS's bilge sump is very deep and narrow - I keep a litterpicker's grabber stick on board to retrieve small items that fall into it, and even then I have to go head and shoulders through the sole hatch to reach. So I didn't want to have any mechanical items down there, even if they fitted which they probably wouldn't. All that's down in the bilge is two hose ends (one with strum box, the other wouldn't fit) and a Salty John solid switch. The manual pump is above the quarter berth (not an ideal location, but needs must on a small boat) and the electric is tucked under the cockpit seat accessible from the lazarette.

Pete

 

[Ubergeekian]

Obviously you'll be wanting to keep the submersible you already have, but for the record I solved this problem by using a motorised diaphragm pump. KS's bilge sump is very deep and narrow - I keep a litterpicker's grabber stick on board to retrieve small items that fall into it, and even then I have to go head and shoulders through the sole hatch to reach.

When I was rebuilding my engine I lost one of the rockers into the sump. Access - just about - is by lying on my side on the cabin sole and reaching through a small access hatch into the bilge and then into the sump, which had - but no longer has - about 4" of unutterable vileness in it. Also a nut, a washer and two useful stainless hose clamps.

A related problem is that the strum box for the real bilge pump is one of the ones which is has the hose going in from the top, and was lying on its side. I'll be replacing that with an end-on one, which will lower the effective height for that pump by a fair bit.

Thanks for the motorised diaphragm pump suggestion.

 

[prv]

When I was rebuilding my engine I lost one of the rockers into the sump. Access - just about - is by lying on my side on the cabin sole and reaching through a small access hatch into the bilge and then into the sump, which had - but no longer has - about 4" of unutterable vileness in it. Also a nut, a washer and two useful stainless hose clamps.

Ah, yes, my engine bilge is separate from the main bilge, and sounds very similar to yours. I try to keep the level of unutterable vileness down to half an inch or so though

Pete

 

[Ubergeekian]

Ah, yes, my engine bilge is separate from the main bilge, and sounds very similar to yours. I try to keep the level of unutterable vileness down to half an inch or so though

That's why I want to improve the pumping arrangements!

The good thing about all of this - even about dropping a tappet into the Sump o' Vileness - is that I'm getting to know Jumblie's systems a lot better. I know, I know, I should have checked it all before, but I got her as a floating, sailing boat and wanted to sail more than investigate last year.

 

[prv]

That's why I want to improve the pumping arrangements!

My engine bilge doesn't have a pump. You also can't get any kind of bailer into it because of the engine squatting above. Emptying it involves a sponge, a basin balanced against the front of the engine, and a very mucky arm.

Pete

 

[Ubergeekian]

My engine bilge doesn't have a pump. You also can't get any kind of bailer into it because of the engine squatting above. Emptying it involves a sponge, a basin balanced against the front of the engine, and a very mucky arm.

Jumblie has (I have now discovered) a fairly shallow bilge under most of the cabin floor (lots of lead there), a fairly shallow bilge under the stern tube and a sump under the engine into which both of the others drain. Above that the engine has its own separate bilge thingy which can take about 2" of water before overflowing into the pits below. I stick one of those giant oil absorbing tampons in there to remove anything nasty before it gets to the bilge ... alas previous owners have not been quite as assiduous.

 

[penfold]

I would second the suggestion of a diaphragm pump for final dewatering, preferably with the suction hose being as short as possible and as small bore as is reasonable commensurate with avoiding blockage. A few ships I've been on that have 'dry bilge' policys use wet/dry vacs and a long snurgly hose to sook the dregs up, but that's probably not a runner on Jumblie I guess...

 

[Ubergeekian]

I would second the suggestion of a diaphragm pump for final dewatering, preferably with the suction hose being as short as possible and as small bore as is reasonable commensurate with avoiding blockage. A few ships I've been on that have 'dry bilge' policys use wet/dry vacs and a long snurgly hose to sook the dregs up, but that's probably not a runner on Jumblie I guess...

She has a traditional stuffing gland and the icebox drains into the bilge as well, so I am resigned to always having some water down there. My main concern with the electric pump is to reduce the short cycling problem. At the moment the pump runs perhaps five times as long as it needs to, which is quite a battery drain.

 

[ghostlymoron]

One of these should do the trick http://cgi.ebay.co.uk/1"-or-1-1/2"-...guid=96f49e5612f0a479e72493a4fdeec4c5#vi-desc fit as close to the pump as you can. I didn't have space near the pump so had to fit in the riser pipe which means that after pump stops, some water runs back but not enough to start the pump again.

 

[Wunja]

I tried fitting a non-return valve to a small centrifugal pump. It would only work the first time it was used. I.E. when there was water above the valve there wasn't enough power in the pump to get the head of water moving.

 

[Trundlebug]

I've read somewhere that it's not recommended to fit a n/r valve in the bilge pump line, as VicS referred to above. The reason being that it's prone to unreliability because of fluff, dust, debris, and general bitty particles making it stick or not seal properly.

My understanding is that the preferred option is to fit an anti-siphon hoop (upturned U thingy) although that won't address your concern about drain back of the pipe contents.