Bilge Pump Non-Return Valve

[Capitain Mike]

Originally Posted by sdowney717

Blue Stocking, where do you get monel screen?

Web Page Search Shows.
monel screen wire - Google Search

[Cheechako]

Originally Posted by Capitain Mike

You are right about the light,
I like the horn idea how about a 3 tone car horn. No I'm not joking
And how about a separate float switch that does nothing but turn the horn on ???

yep, i think that is more common on commercial vessels but a great idea. I have only used the Senior or Junior, plastic tube enclosed switches for years. great switches.
Bronze screen door mesh is still sold in good old fashioned hardware stores. I wouldnt go too fine a mesh though.

[cburger]

I have had the opportunity to see many failed check valves over the years. One thing that I haven't seen mentioned here is that starting the small cheapy 12v plastic bilge pumps against a head of water (Weight) will shorten the pumps life expectancy.

[Chief Engineer]

In cold climates, the water in the hose will fillup/freeze....then you have no bilge pump(s).

I have seen a couple boats with diaphagme pumps which eliminate the residual water.

Or use a manual bilge pump or wetvac.

[sdowney717]

Originally Posted by Capitain Mike

Web Page Search Shows.
monel screen wire - Google Search

I looked thru some adds and they want a lot of money for minimum orders.
So perhaps I can get something local?
How about stainless mesh?

[jackcon]

Stainless mesh might be a better option here: Check out either Mcmaster or Belleville Wire Cloth for this or the monel material. Not sure the difference between stainless and monel (other than the large difference in price), but if you need monel, then you have to pay the extra premium. Check here:

Custom Wire Cloth - Belleville Wire Cloth Co - Cedar Grove, NJ

[ChannelIslander]

Thanks for all the knowledge shared in this discussion.

A little empirical experience from today:

I installed a new Rule 500 in my shower sump. As a matter of fact new everything from the battery switch, since I also pulled new wire and just rebuilt the electrical panel. Didn't like the backflowing water which half refilled the tiny sump, since the 3/4" discharge hose has a nice high anti-siphon loop. Got an in-line check valve with simple rubber flapper from Worst Marine, but it leaked back a constant drip that would have returned all the water in no time, so I yanked that out before I could even really tell if there was an issue with head pressure. Went to Ace and got a spring action valve: the Rule 500 could not overcome the head, which was about 3.5 ft vertical, 4.5 ft overall x 3/4" hose.

So while this is not a bilge story per se I can testify to the reality of the head pressure problem with a check valve.

But I am going to upgrade my bilge pump system after reading this discussion!

[Ex-Calif]

Four years ago or so I had a single failed manual whale diaghram pump. Not finding a good rebuild kit I replaced the pump and inquired here on CF about adding an electric pump in the bilge inline with the whale. I didn't want to poke another hole in my boat.

I (probably correctly) was told how terrible this idea was and how I would end up sinking my boat, ruining the diaghram pump and the rule wouldn't overcome the head anyway.

4 years later the rule and the wobble pump are fine and the bilge is mostly dry as I do have the same backflow problem that OP has. In my case the amount of water does not reactivate the electric pump. My ingress in case anyone is wondering is a constant chasing of fresh water leakage around cockpit lockers - no amount of resealing lasts very long - grrrrr...

The only real learning on my part is that it is preferable to me to have a seprate float switch. The integral switch in my rule failed after 3 years and I installed a separate float switch, that when it fails, and I am sure it will, can be easily replaced.

On a bigger boat with multiple bilges I would not choose to put these pumps in line and would bow to conventional wisdom.

[senormechanico]

This looks like a good idea.
The company's solution is for high end boat owners, but anyone with a little ingenuity could make his own system.
It's basically a sponge on a stick/tube with a weight to hold it down.
Hook that to a self priming pump, put a timer on it.
Done, and congratulate yourself for a dusty bilge.

Pickup Types & Specs

[GordMay]

Greetings and welcome aboard the CF, jackcon and ChannelIslander.

[waterdancer]

Originally Posted by ChannelIslander

Thanks for all the knowledge shared in this discussion.

A little empirical experience from today:

<SNIP>
So while this is not a bilge story per se I can testify to the reality of the head pressure problem with a check valve.

But I am going to upgrade my bilge pump system after reading this discussion!

All very true. There are at various times 3 ways I solver that problem.
1- Use a diaphram pump like the whale gulper, with very narrow lhoses (3/8 id) on the inlet, and a check valve right at the bilge. The check valve is just to help priming. Whatever is in the hose section below the pump will eventually leak back.
2- Use a very small bulge pump, and run it to the bathroom/shower sump if you have one. You will effectively use 2 pumps, but will keep the bilge dry.
3- Just simply use the small Rule 500 on a narrow line and live with about 1/4 - 1/2 inches of water in the bilge.
The most effective is using (#2)

Of course this is assuming that you have at least one, if not 2 real Bilge pumps minimum 1500 + GPS (depending on the size of your boat,) to take care of the actual water influx

[Cheechako]

Originally Posted by ChannelIslander

Thanks for all the knowledge shared in this discussion.

A little empirical experience from today:

I installed a new Rule 500 in my shower sump. As a matter of fact new everything from the battery switch, since I also pulled new wire and just rebuilt the electrical panel. Didn't like the backflowing water which half refilled the tiny sump, since the 3/4" discharge hose has a nice high anti-siphon loop. Got an in-line check valve with simple rubber flapper from Worst Marine, but it leaked back a constant drip that would have returned all the water in no time, so I yanked that out before I could even really tell if there was an issue with head pressure. Went to Ace and got a spring action valve: the Rule 500 could not overcome the head, which was about 3.5 ft vertical, 4.5 ft overall x 3/4" hose.

So while this is not a bilge story per se I can testify to the reality of the head pressure problem with a check valve.

But I am going to upgrade my bilge pump system after reading this discussion!

Yea, those little bilge pumps wont push back against much at all. Those spring loaded hardware store checkvalves take a lot to depress the spring. I've been successful with a plain bronze flapper (no spring)mounted horizontally if you have a horizontal hose run. Wanna get rich? Invent a marine positive displacement bilge pump with good output at a reasonable price and size envelope!

[Blue Stocking]

My bilges are 3 1/2 ft below the salon floor, with another 1 1/2ft up to the 1" diaphram pump. I have the gravity clapper type non-return between the strainer and the hose. The brass non return has had almost all the clapper material removed to make it as light as possible. The pump has little work to do to provide to reduced atmosphere in the hose to lift the clapper.
Keep in mind that those clappers are designed to withstand 100+psi back pressure. Thats 230ft of head, AAMOI

[Ex-Calif]

All these posts and no one has solved the problem. The second, low capacity pump installation is slightly inelegant imo. I am reading in fascination and scratching my head like others. It is always useful to remember the problem we are trying to fix.

- problem. The hose leading from the pump to the thru hull holds enough water to lift the switch and cycle the pump back on when the water drains back into the bilge

What about a double pole solenoid with two switches. A high switch that closes a solenoid to power the low switch. When the high switch makes it closes a solenoid powering the low switch, the solenoid power circuit is run through the low switch so it is made until the low switch breaks i.e. when the solenoid closes the circuit is completed through the low switch to both power the pump and act as a holding relay for the solenoid. When the low switch breaks, the solenoid is depowered and wont be repowered until the high switch makes again.

This is basically what the float switch does mechanically - i.e. makes at 2 inches and breaks at 1 inch or something like that. You are just doing it electrically due to need for bigger throw.

Water will still run back into the bilge but the pump wont cycle until the high switch is again made.

Other than redesigning the bilge space to accomodate the back flow without rasing the pump switch I dont see another solution.

[psneeld]

stop all leaks and use a shop vac?