Solvent Weld ABS Pipe for Narrowboat Pump out Fittings

[Simon D]

I have just bought a boat with a Vacuflush Cassette toilet, and I want to fit a much bigger holding tank and go for a pump out system.

 

I have got a quote for the stuff from Lee Sanitation and that all seems straight forward, but then my surveyor (a man whose judgement I have learned to trust in the past) said

 

"Avoid using hoses to plumb in if you possibly can. Even Leesan sanitation grade hose becomes permeable to odour in time. The best material is rigid solvent weld ABS, but the same in PVC is adequate if not exposed to UV. Plumb feed to tank, pump out line and vent line using rigid pipe, using hose only where essential and only as a jointing collar, i.e. with the minimum of hose exposed to sewage odour."

 

I don't mind which I use, LeeSan pipe or ABS, they are both pretty easy to plumb in. The ABS will be a bit cheaper but not that much difference. But which would give the best overall long term solution?

 

If I go for the ABS do you go for the standard house plumbing stuff from B&Q or Wickes (which looks a bit lightweight to me) or can you get heavier duty stuff?

 

Any thoughts or comments gratefully received.

 

Simon

[Bill]

I originally plumbed my Tecma PO - holding tank with Leesan hose, after about 2 1/2 years there was a distictive odour appearing. I placed wet paper towels on the hose and left for a day or so, when I removed them and sniffed the smell was on the towels (i.e. the hose was to blame). Replaced with solid solvent weld ABS (just using a very short length of hose to connect to the spigot on the holding tank), 6 years later and still no smells.

[Ex- Member]

Personally I would go with the glued pipe. Rubber hose and jubilee clips and similar can fail/loosen and exude smells over time.

 

You're pretty sure of a good seal with that pipe glue, that's for sure.

[Bobbybass]

Nasty smelly stuff flexible pipe...

I found that the pipe that DIDN'T carry liquid was the worse..?....ie the vent pipe...?

LeeSan said this could not be...so I took them some to sniff !!

 

All gone now and replaced with Lee San solvent weld...

Its very strong .....but there are short lengths of flexi to attach it to the fittings.

This is to absorb any impacts that may be suffered by the boat and prevent fracture...

 

Years later...no smell..happy bunny...

[Ex- Member]

There are some flexible waste pipes that you could use with initial connection to counterac movement. I'm not sure though if they will interconnect with abs waste.

 

Still a short rubber host and a couple of quality jubilee clips might do, handy if accessable though.

 

http://www.google.co.uk/shopping/product/1991725458872738538?hl=en&sclient=psy-ab&q=flexible%20waste%20pipe&oq=flexible+waste+pipe+&gs_l=serp.12...26263.26784.7.29227.4.4.0.0.0.1.2845.2845.9-1.1.0...0.0...1c.1.8.psy-ab.U4HgzZfUSOE&pbx=1&bav=on.2,or.r_qf.&bvm=bv.44990110,d.d2k&biw=1366&bih=619&sa=X&ei=j75lUY28B6mJ0AWGxIHgBQ&ved=0CHgQ8wIwBg

Edited April 10, 2013 by Julynian

[MtB]

If I go for the ABS do you go for the standard house plumbing stuff from B&Q or Wickes (which looks a bit lightweight to me) or can you get heavier duty stuff?

 

There is certainly heavy duty stuff available in uPVC solvent weld. It's not that easy to find and costs three times as much, but both the fittings and the pipe are a whole load more substantial than the flimsy ABS stuff widely sold. It's fully compatible with standard weight ABS and uPVC tube.

 

MtB

[steve hayes]

After reading stuff on here, changed the run from the loo to the holding tank from Lee San flexible (stank something rotten) to B&Q solvent weld. Three years later still perfect and no smell.

Didn't change the pump out or vent pipes, but did wrap them in auminium tape, maybe my next job ?

[fudd]

 

There is certainly heavy duty stuff available in uPVC solvent weld. It's not that easy to find and costs three times as much, but both the fittings and the pipe are a whole load more substantial than the flimsy ABS stuff widely sold. It's fully compatible with standard weight ABS and uPVC tube.

 

MtB

We built a swimming pool a few years ago. The fitter or plumber used this heavy duty stuff. It was about 5mm thick. Maybe overkill but he obviously found it necessary to use with plain old water. If I ever plumb a toilet system in I'll be using the same stuff. It was really heavy. Proper job.

[smileypete]

The big koi suppliers sell PVC 'pressure pipe' and solvent weld fittings in all different diameters and thicknesses, but it's going to cost a fair bit more than normal domestic solvent weld waste pipe.

 

Good to hear that wrapping hose in ali tape is working out for some people.

 

cheers, Pete.

~smpt~

Edited April 11, 2013 by smileypete

[Robbo]

LeeSan sell thicker ABS solvent weld piping that can have 38mm hose connectors.

[Fred_Smith]

From my own experience use as little of that white flexible pipe as possible, (perhaps only use where you need to put a curve in) it will smell. I used poly pipe (its cheaper than flexi) or a similar make and push fit is as good as welded

[Simon D]

From my own experience use as little of that white flexible pipe as possible, (perhaps only use where you need to put a curve in) it will smell. I used poly pipe (its cheaper than flexi) or a similar make and push fit is as good as welded

 

I wondered about that, You can get the "Compression Fit" stuff for 40mm waste fittings, like the push fit with a rubber ring, but with a screw tight compression ring to make the seal more secure. That must be pretty resistant to both odour and vibration, and also cheaper, and fully dismountable/adjustable.

 

Simon

[Bill]

I wondered about that, You can get the "Compression Fit" stuff for 40mm waste fittings, like the push fit with a rubber ring, but with a screw tight compression ring to make the seal more secure. That must be pretty resistant to both odour and vibration, and also cheaper, and fully dismountable/adjustable.

 

Simon

 

I like the demoutable/adjustable idea, good it it ever gets clogged with something. However, I think people are making too much of the vibration thing, if you are in the habit of crashing your boat into solid objects on a regular basis or have an engine that mimics a road layers vibration plate I would think that the solvent weld pipe would be one of the last things to fail. Provided that there are not massive unsupported runs (should be clipped anyway to prevent sagging) the actual mass of the pipework is minimal so in the event of a collision the kinetic energy is minimal, far more likely that the bog itself would rip out its holding down screws and make a run for freedom .

[Simon D]

Excellent, many thanks, I think we have a plan.

 

Pipework in 40mm waste pipe, mixture of solvent weld and compression fit bends, elbows and connectors as seems sensible, but enough compression fit to be able to strip it down for cleaning out blockages (there are some long pipe runs).

 

Connect up to the Leesan deck fittings and pipe fittings with these things:

 

http://www.screwfix.com/p/flexi-waste-straight-coupling-38-45mm/81383,

 

or a bit of Leesan pipe with 2 pipe clips.

 

Final question. Do the Leesan Uniseal tank fittings work directly with 40mm waste pipe (or some other size) or do I need to buy the Leesan adaptors and connect to those?

 

Again thanks for any advice.

 

Simon

[smileypete]

Another to provide access for cleaning is to use a swept tee instead of an elbow (see the second comment in the reviews):

 

http://www.screwfix.com/p/floplast-solvent-weld-40mm-tee-black-pack-of-3/64518

 

with the unused branch facing away from direction of flow, then put an access plug in the unused branch:

 

http://www.screwfix.com/p/floplast-solvent-weld-40mm-access-plug-black-pack-of-5/65881

 

This can also be done on a long pipe run, have the tee put in with a plug on the 'end' of the tee, bit like this:

 

 

Also I believe sh*t rolls downhill in a pipe best if the angle is 2.5 - 5°, may need to go a bit steeper on a boat though, also anything over 45° can be considered as if vertical and shouldn't be a problem. With long horizontal runs >3m it may be best to step up to bigger pipe, Leesan may have some info on what's best to do.

 

BTW BES Gas and Plumbing are another good source of bits, wide range, cheaper prices on the whole, and they do things in singles.

 

http://www.bes.co.uk/

 

cheers, Pete.

~smpt~

Edited April 14, 2013 by smileypete

[Chris3]

Hope I have not picked up on this thread too late as I have similar vacuflush odour problems !

 

I fitted a boat out once with a macerator type loo . The macerator being at the back of the pan. I used cheap transparent flexible pipe from floor level to the underside of the gunwale and formed a slight 'u' bend before attaching to domestic upvc waste pipe and down the length of the boat to the tank at the rear. Never any odour problems.

 

I now have a boat with a vacuflush loo system. From the back of the pan the flexible pipe runs into a pressure vessel and from the vessel to the pump, a distance of 5 meters. The pump discharges straight into the tank via 300 mm of flexible pipe.... system all supplied by Leesan.

 

Now I am confused here ( not difficult these days ) as to how the vapour can escape through the wall of the 5 meter pipe and pressure vessel when it is under negative pressure ? Also as this length of pipe is flushed clean why should it smell that much ?

 

Would putting a gentle 'u' bend in the dishcharge line from the pump, as per my previous installation, help form a vapour barrier as in a domestic sink/bath or loo applications and prevent vapour back feeding into the system from the tank ?

 

The odour certainly seems to come from the 5m length of pipe which is under vacuum.

[Biggles]

I've just ripped out rubber "Sanitary hose" after a little over a year because of the smell. I've replaced it with push and lock fit ABS with a tiny amount of a corrugated flexible pipe and so far nothing smelling.

 

It might be early days but I think its cured the problem.

 

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[John&Lou]

Sorry to resurrect this topic, but it seems to hold the key to a problem we've found on our new boat.

 

The holding tank on our narrowboat is under one end of the bed, with a flexible hose travelling the full length of the bed, out through two cupboards and finally joining the pump outlet near the stern.

 

The smell from under the bed and in the cupboards is unpleasant to say the least! There's no smell in the toilet, so it has to be the pipe that's exuding the aromas?

 

It seems that a new pipe run is the answer, but as a temporary measure, has anyone tried using phenolic foam insulation pipe and aluminium tape to try and keep the stench in?