TMC vented loop duckbill valve not working

webcraft

webcraft

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We have been out of the water for three weeks, during which time I replaced heads seacocks and hoses and serviced the Jabsco pump.

Both inlet and outlet have TMC vented loops, which I reused. They used to soletimes splutter a bit, but did not actually leak.

Now the outlet jets water out. I tested the duckbill valve - took the cap off and I can blow into it but not out of it, so I cannot understand the problem.

There is no hope of getting replacement duckbill valves here in Portugal, or TMC loops, so I am a bit stuck. There is obviously a lot of pressure, sticking duct tape over the wee hole does not stop the spurts.

I am thinking of just filling the cap with sikaflex (or CT1} as a temporary fix until I can get a new vented loop. Can anyone see any issue - other than a potential siphon of course?

- W
 
If you are getting that much pressure, isn't there a good chance of a blockage/restriction at the outlet.

I had this a few years ago when I used a few rolls of posh toilet paper...it built up in the outlet but didn't actually block it completely for quiet some time...
 
It's a brand new seacock, Trudesign, just fitted professionally. New Vetus hoses. No paper been down it.

I didn't check to make sure it was open fully, SWMBO did. Now I am wondering. Will be back on board in an hour.

Knackered after a three and a half week mini-refit, not thinking properly.

- W
 
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webcraft said:
It's a brand new seacock, Trudesign, just fitted professionally. New Vetus hoses. No paper been down it.

I didn't check to make sure it was open fully, SWMBO did. Now I am wondering. Will be back on board in an hour.

Knackered after a three and a half week mini-refit, not thinking properly.

- W
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If it is open fully, is there a chemical solution you could use to flush to make sure nothing is messing up pipe work whilst out of the water? I have used caustic soda or drain cleaner in domestic situations , cleared a 6 foot sewer blockage in garden once but not sure if safe to use on seacocks even if they are composite. I think I was very lucky to have never had trouble with the heads in my time after reading these forums.
 
OCuea said:
If it is open fully, is there a chemical solution you could use to flush to make sure nothing is messing up pipe work whilst out of the water? I have used caustic soda or drain cleaner in domestic situations , cleared a 6 foot sewer blockage in garden once but not sure if safe to use on seacocks even if they are composite. I think I was very lucky to have never had trouble with the heads in my time after reading these forums.
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Pipework and seacocks are brand new, as in never been used new.

Sitting here digesting and more and more convinced outlet is almost totally closed. Off back to the boat in a minute to check.

- W
 
webcraft said:
Pipework and seacocks are brand new, as in never been used new.

Sitting here digesting and more and more convinced outlet is almost totally closed. Off back to the boat in a minute to check.

- W
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Good luck, hope it is warmer wherever you are than where I am. Do you have a camera that fits to your phone and will snake up the through hull?
 
OCuea said:
If it is open fully, is there a chemical solution you could use to flush to make sure nothing is messing up pipe work whilst out of the water? I have used caustic soda or drain cleaner in domestic situations , cleared a 6 foot sewer blockage in garden once but not sure if safe to use on seacocks even if they are composite. I think I was very lucky to have never had trouble with the heads in my time after reading these forums.
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It IS open fully, it seems.

There cannot be any blockage, it is a brand new seacock and brand new Vetus sanitary hose.

I can stop the flow by putting my finger over the top of the vent, so not so much pressure.

One of the weird things I do NOT understand is that when I close the seacock the hissing and spurting stops, only to restsrt when I open the seacock (without pumping)

I sm struggling to find a way tl close the valve off.

- W
 
Both valves removed and the openings sealed with 'washers' made from doubled electrical tape.

No leaks. So - potential siphon sinkage, but a working heads. Looks like both the duckbill valves have failed in a weird way. I can't blow through them, but water moving horizontally past them obviously forces their wee ducky bills open.

I can live with this for now. Will bring new valves back from the UK in the Autumn before our big trip.

- W
 
webcraft said:
Both valves removed and the openings sealed with 'washers' made from doubled electrical tape.

No leaks. So - potential siphon sinkage, but a working heads. Looks like both the duckbill valves have failed in a weird way. I can't blow through them, but water moving horizontally past them obviously forces their wee ducky bills open.

I can live with this for now. Will bring new valves back from the UK in the Autumn before our big trip.

- W
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Congrats. Pbo style
 
Alex_Blackwood said:
Duck bill valve.
Google Search

For OP. You don't by any chance have something fitted A about F ?:unsure: Wouldn't be the first, or last, time;)
Or have you left something in the pipework? Perhaps consider, going through each item one by one and checking.
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What exactly do you suggest could be A about F? The new seacocks are professionally installed and pipe is off a new, sealed Vetus roll of 38mm hose. Pumping action is smooth with no extra/unusual effort required. The amount of pressure involved is small - putting my finger over the hole stops the leak completely.

The duckbills spluttered a bit before. I think it was a developing problem. Am going to try plumbers tape on the threads of the caps that contain the valves.

- W
 
webcraft said:
What exactly do you suggest could be A about F? The new seacocks are professionally installed and pipe is off a new, sealed Vetus roll of 38mm hose. Pumping action is smooth with no extra/unusual effort required. The amount of pressure involved is small - putting my finger over the hole stops the leak completely.

The duckbills spluttered a bit before. I think it was a developing problem. Am going to try plumbers tape on the threads of the caps that contain the valves.

- W
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I have absolutely no idea what may or not be A about F or anything else, just tried to make a helpful suggestion. Which is also why I said check each item individually. Good luck with getting sorted. ;) (y)
 
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