Non-return (one-way) valve - use with heads?

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davidej

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I posted some time ago about the problem we have with the contents of the outlet pipe from the heads back filling into the bowl. The boat has a holding tank and so the outlet pipe from the pump to the top of the tank is about 2 metres long and there is a rise if about 1 meter. The joker (choker?) valve should hold this back and a new one does so for a while but after a couple of months the back-filling starts again.

I feel the problem is that the joker quickly picks up calcium deposits and this stops it closing properly. I know I could just change the joker more often but three times a season seems excessive! However someone suggested a Jabsco non-return valve in the pipe might cure it.

I went to my local chandlers to get one but they only had a Whale one in stock which I bought. Looking at it when I got hone it seems to just the the same sort of tricuspid valve as the joker and so will probably succumb to the same problem.

Does anyone know of the Jabsco valve is different and thus might be more effective
 
davidej said:
I posted some time ago about the problem we have with the contents of the outlet pipe from the heads back filling into the bowl. The boat has a holding tank and so the outlet pipe from the pump to the top of the tank is about 2 metres long and there is a rise if about 1 meter. The joker (choker?) valve should hold this back and a new one does so for a while but after a couple of months the back-filling starts again.

I feel the problem is that the joker quickly picks up calcium deposits and this stops it closing properly. I know I could just change the joker more often but three times a season seems excessive! However someone suggested a Jabsco non-return valve in the pipe might cure it.

I went to my local chandlers to get one but they only had a Whale one in stock which I bought. Looking at it when I got hone it seems to just the the same sort of tricuspid valve as the joker and so will probably succumb to the same problem.

Does anyone know of the Jabsco valve is different and thus might be more effective
Click to expand...

the in=line jabsco is as near as damn it the same valve.
my Lavac outlet rises approx 800m/m to the deck hd before dropping down to the seacock.
i replaced the pump over 2 yrs ago with no drain back. are you pumping enough to clear the solids from the discharge pipe riser
 
davidej said:
I posted some time ago about the problem we have with the contents of the outlet pipe from the heads back filling into the bowl. The boat has a holding tank and so the outlet pipe from the pump to the top of the tank is about 2 metres long and there is a rise if about 1 meter. The joker (choker?) valve should hold this back and a new one does so for a while but after a couple of months the back-filling starts again.

I feel the problem is that the joker quickly picks up calcium deposits and this stops it closing properly. I know I could just change the joker more often but three times a season seems excessive! However someone suggested a Jabsco non-return valve in the pipe might cure it.

I went to my local chandlers to get one but they only had a Whale one in stock which I bought. Looking at it when I got hone it seems to just the the same sort of tricuspid valve as the joker and so will probably succumb to the same problem.

Does anyone know of the Jabsco valve is different and thus might be more effective
Click to expand...

You need the Jabsco "twist and lock" pump mechanism. This works for us with two Jabscos.

Richard
 
pvb said:
Why not fit a Twist 'n' Lock pump?
Click to expand...
RichardS said:
You need the Jabsco "twist and lock" pump mechanism.
Click to expand...

....and they'll throw in a new joker valve. But only one ;)

I have a similar set-up to the OP, with about a 1m rise to the top of the holding tank. Twist and Lock has solved the problem. Only £100 from Force 4, much of which effectively became a cost-effective spares package.
 
Fitted one of those years ago - sotry to say it doesn't seem to solve the problem.

We pump plenty when solids in the system but maybe not enough when it is urine. Must try harder as I assume that is what causes calcification
 
Last edited:
davidej said:
We pump plenty when solids in the system but maybe not enough when it is urine. Must try harder as I assume that is what causes calcification
Click to expand...

I believe the Jabsco figure is 7 strokes per metre. I have three metres of hose so give it 20+ strokes on the pump every time to flush everything out, and instruct everyone else to do likewise.

Pete
 
prv said:
I believe the Jabsco figure is 7 strokes per metre. I have three metres of hose so give it 20+ strokes on the pump every time to flush everything out, and instruct everyone else to do likewise.
Click to expand...

The OP mentioned a holding tank, and I think there's a tendency for people with holding tanks to flush minimally.
 
prv said:
Then they have problems :)

Pete
Click to expand...

Quite correct, we even restrict forward head to liquid and aft for solid to extend time to fill the tank. However, that's only when we are going to be in an anchorage for a week. Vigorous flushing when just stopping overnight (7 strokes / metre of pipe + 2 is our minimum).

Twist and lock can still allow seepage into the bowl, so not a guaranteed cure. However, it is OK almost all of the time but not to be relied upon as a solution to the problem.
 
pvb said:
Why not fit a Twist 'n' Lock pump?
Click to expand...

It certainly did not solve the problem for me, in fact the twist and lock works by an extension piston rod pressing down on the flap valve at the bottom of the pump, preventing it lifting, but in time distorting it so that it no longer seals. I am seriously considering fitting a spring loaded non return valve into the vertical pipe to my holding tank, but am unsure if the Jabsco pump will cope with the load it will impose.
 
Norman_E said:
It certainly did not solve the problem for me, in fact the twist and lock works by an extension piston rod pressing down on the flap valve at the bottom of the pump, preventing it lifting, but in time distorting it so that it no longer seals. I am seriously considering fitting a spring loaded non return valve into the vertical pipe to my holding tank, but am unsure if the Jabsco pump will cope with the load it will impose.
Click to expand...

you might try a "clack" valve in the riser
 
Not sure what make we have ( Might be Domretic) because we are in the USA but when our Loo expert fitted a new Jabsco 'twist 'n lock for us, he added a check valve ( ie a non-return valve) and it is fine, that was his normal practice not because we had reported a problem, but our holding tank inlet is 8ft above the loo outlet, so could contain a lot of 'content' trying to escape back down! Is someone confusing a clack valve with a check valve, they sound similar.
 
sailorman said:
#14 asked where to get one
it seem ebay could be a source :encouragement:
i didnt realise he need to be spoon fed
Click to expand...

He did in fact ask where he could get a SUITABLE one ........ 3/4" would not be suitable!

I'd suggest ASAP supplies
 
Last edited:
Robin said:
Not sure what make we have ( Might be Domretic) because we are in the USA but when our Loo expert fitted a new Jabsco 'twist 'n lock for us, he added a check valve ( ie a non-return valve) and it is fine, that was his normal practice not because we had reported a problem, but our holding tank inlet is 8ft above the loo outlet, so could contain a lot of 'content' trying to escape back down! Is someone confusing a clack valve with a check valve, they sound similar.
Click to expand...
Two countries divided by a common language. :D
 
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