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

[rob2]

I guess I don't use the heads as much as the OP, but I believe that many jokr valves are replaced when all they actually need is cleaning. It's not a pleasant job, but fairly quick. I find that if done early enough (wearing Marigold gloves) simply wiping between the fingers will slough off all the slime and calcium. I believe some people grease them with silicon grease, but I don't bother.

Rob.

 

[RichardS]

I guess I don't use the heads as much as the OP, but I believe that many jokr valves are replaced when all they actually need is cleaning. It's not a pleasant job, but fairly quick. I find that if done early enough (wearing Marigold gloves) simply wiping between the fingers will slough off all the slime and calcium. I believe some people grease them with silicon grease, but I don't bother.

Rob.

I think the Jabsco manual says not to grease any of the butyl valves with silicone grease. I must admit that I have always ignored that advice and never had a problem.

Richard

 

[Cantata]

I think the Jabsco manual says not to grease any of the butyl valves with silicone grease. I must admit that I have always ignored that advice and never had a problem.

Richard

Me too, never in 15 years of owning these loos. Must be something the OP is or is not doing. Perhaps the most likely reason is not enough pumping?

 

[cmedsailor]

Same boat as the OP, same problem even with a twist n lock pump. When the joker valve is new all OK. But after a few months i also get waste back no matter how many times i pump (definitely more than 20). And i mean lots of waste, nearly a full bowl. I cannot understand why either. It seems that there is back pressure though i think this is impossible because of the vent hose of the holding back.

 

[sailorman]

I think the Jabsco manual says not to grease any of the butyl valves with silicone grease. I must admit that I have always ignored that advice and never had a problem.

Richard

soapy water now & then would help lube the rubber elements. our head basin is pumped via the Lavac so we get plenty of soapy water through ours. vinegar also helps reduce the calcium build up

 

[Fendant]

Same problem here, my holding tank is 3 ft above the loo. Twist and lock works well when new.
I am now servicing my loo once a month:
a) Add decalcifier and pump until it is in the sh..t raiser pipe, let it rest for 15 - 30 mins
b) Flush intensively
c) Add a loo valve oil and let it rest over night ( I mostly do it before we leave the boat on Sunday evening )

 

[Robin]

soapy water now & then would help lube the rubber elements. our head basin is pumped via the Lavac so we get plenty of soapy water through ours. vinegar also helps reduce the calcium build up

Yes but there is a non-return valve built in to the diaphragm pump on the Lavac too not just the joker valve ( called a duck bill valve here in the USA just to be different) which I'm not sure even exists on a Lavac which has a completely separate Henderson diaphragm pump like a bilge pump, with built in valves. THE real culprit is the holding tank which is mounted higher than the loo like in our case where a vertical tank in a locker has the inlet at the top, just below deck level so that the loo contents have to travel some 8ft upwards before reaching the tank and will try and drain back downhill to the loo with only the rubber joker/duckbill valve in the Jabsco to stop it going back into the bowl unless a separate check/clack/ non-return valve is installed in the outlet pipe to the tank. Most Brit boats do not even have holding tanks unless they have been to the med or are new builds and the outlet pipes go to an overboard seacock so no real 'head' of stuff to fall back but IIRC the Lavac outlet pipework normally goes up to a point above the waterline to prevent a siphon and has a small pinprick plastic valve in the highest part of the loop to break the vacuum and thus allow the seat lid to be opened again.

 

[pvb]

...but IIRC the Lavac outlet pipework normally goes up to a point above the waterline to prevent a siphon and has a small pinprick plastic valve in the highest part of the loop to break the vacuum and thus allow the seat lid to be opened again.

The Lavac air bleed valve goes in the inlet pipe, not the outlet pipe!

 

[VicS]

k but IIRC the Lavac outlet pipework normally goes up to a point above the waterline to prevent a siphon and has a small pinprick plastic valve in the highest part of the loop to break the vacuum and thus allow the seat lid to be opened again.

No but some people have made that mistake. If you put the pin prick vent in the outlet it sprays "waste" water all over you.

The pin prick is in the inlet pipe!

 

[Robin]

No but some people have made that mistake. If you put the pin prick vent in the outlet it sprays "waste" water all over you.

The pin prick is in the inlet pipe!

OK OK it has been 15 years since we had a boat with a Lavac but we do have a Jabsco 'Twist 'n lock' in an installation with a holding tank mounted above the toilet. When we bought this boat it had an older Jabsco with an electric pump conversion that was faulty and leaked and there was some drainback evident. Our installer of the new simple manual unit, who is the local equivalent of 'Headmistress', recommended fitting an additional non return valve which he did and we have had no problems (yet). We are obliged to have a holding tank here and one was fitted on our boat when it was first imported from Beneteau France back in 1998. We had a Jabsco on our ladst UK boat also with a holding tank but in that case the tank was not above the Jabsco.

Another possible cause for the OP's problem might be pressure in the holding tank if perhaps the vent pipe was blocked or partially restricted, in which case excessive loo pumping in an attempt to fullyempty the pipe from the loo to the tank would actually make the problem worse??

 

[davidej]

I am sorry to be so stupid as to need spoon-feeding.

However I took "clack valve" to mean a flap valve while a check valve seems merely another name for non-return valve.

ASAP's check valves are made of fire resistant GRP designed for exhaust systems - hence not very suitable.

The ebay objects cited certainly would not fit or be suitable for a 1 1/2 in sanitary hose as used in heads.


Can I please rephrase my question.

"Does anyone know of a valve suitable for the use stated that isn't a tricuspid valve (which would probably suffer the same fate as the joker valve in the jabsco pump outlet)"

 

[pvb]

"Does anyone know of a valve suitable for the use stated that isn't a tricuspid valve (which would probably suffer the same fate as the joker valve in the jabsco pump outlet)"

Your best bet would be to try a bilge pump valve, such as this one - http://www.jabscoshop.com/marine/pu...ories/29295-1010-in-line-non-return-valve.htm

I imagine it's a simple flap valve. Whether this will allow the free passage of waste reliably you'll have to discover. I have to say that, kept clean, the common or garden tricuspid joker valve is about as reliable as you can get.

 

[davidej]

Your best bet would be to try a bilge pump valve, such as this one - http://www.jabscoshop.com/marine/pu...ories/29295-1010-in-line-non-return-valve.htm

I imagine it's a simple flap valve. Whether this will allow the free passage of waste reliably you'll have to discover. I have to say that, kept clean, the common or garden tricuspid joker valve is about as reliable as you can get.

Well is it ?? That is the original question and we are now one page 4 !!!


I imagined the Whale one would be a flap valve but when I opened the packaging at home I found it was a tricuspid.

 

[pvb]

I imagined the Whale one would be a flap valve but when I opened the packaging at home I found it was a tricuspid.

That's because the tricuspid is the most reliable!

The shape of the Jabsco one I linked to would suggest a conventional flap valve.

Edit: The Jabsco valve is used with Jabsco electric toilets - see http://www.njy.co.jp/jabsco/toilet/jab-dxman.pdf

 

[Cantata]

Well, you must be getting some back pressure for some reason. Maybe the interior of the outlet hose has delaminated and collapsed, party blocking the tube? Is there a anti-siphon valve at the top of the loop in the outlet pipe? On my boat there originally wasn't and the pipe collapsed and kinked at the top of the loop.

 

[theoldsalt]

Just fit a shutoff valve in the toilet bowl discharge pipe to stop the back flow - don't fuss around with a non return valve that can fail.

Maybe add a notice in the heads to turn on before and to shutoff after pumping out; simples.