Sourcing 40mm diameter Sanitation pipe for a holding tank to Y valve connection

May 11, 2013
1
Beneteau Oceanis Clipper 42CC Dartmouth
My 90 degree head of the holding tank coupler in PVC has cracked and this the second time a problem with this. This found upon inspection recently, but in 2015, the coupler broke under use, with awful consequences. I suspect that the connector pipe, surrounded by a metal helix is simply too rigid and stiff, with movement of the boat, under way, or at anchor with a chop, this exerts forces on this coupler. I have sourced new couplers, one for spare, and am now trying to source a new 2m length of 40 mm diameter pipe. This is proving very difficult. It seems as if everyone is saying that 38mm (1 1/2 " ) is the standard and I should use hot water and detergent to slip this on. I have sourced a sample of 40mm diameter steel helix surrounded pipe, a non marine, lighter weight PVC helix surrounded 40mm diameter pipe and these fit. The boat yard fitter has said that this non marine PVC helix surrounded pipe would end up creating smells. He would help to fit it, but my call re smell risk. It has the advantage to my mind, it should exert less stress on the coupling. Having been told by many marine suppliers, not only in the UK, but Denmark also, that 38mm diameter is the standard for sanitation pipe, using boiling water and detergent is the way to go to ease it on. I obtained a sample of 38mm diameter PVC helix surrounded pipe from a local chandlery, and tried to fit this over a 40mm diameter male end from the coupling. This proved impossible, as well as risky in puttng a too tiight pipe onto a thicker male end. Any thoughts from anyone on this welcomed, particularly of known suppliers who would supply sanitation pipe, PVC helix, smell retarding, with 40mm diameter internal. Particularly in Europe, but if not worldwide. Someone in Italy has suggested he could get it for me, from an Italian chanlder, but the minimum order is 50m. I clearly do not need this much. I am trying a German supplier, but await an answer. All input appreciated.
 
Jan 7, 2011
4,726
Oday 322 East Chicago, IN
First, your hose should match your fitting...so what size fitting Barb is it?
Also, non-sanitation hose will be permeated by sewage smell. Sanitation hose is designed to minimize this.

yes- hose like Triton 101 is VERY stiff. I replaced a section of mine this year, and it is very hard to bend.
but with careful manipulation, I was able to replace it. While hot water or a hair dryer makes it easier to get over a barbed fitting, you have to make sure the hose is routed correctly and trimmed to the correct length to not put stress (particularly lateral stress) on the fitting.

There is a “flexible” sanitation hose, endorsed by our local sanitation expert (@Peggy Hall head mistress) called Raritan saniflex. Here is a link to a recent post about sanitation hose....

i really don’t know about international options. Sorry.

Greg
 
Dec 2, 2003
751
Hunter 260 winnipeg, Manitoba
Is it pipe or hose? If it’s rigid pipe, 2m long, supported only at the ends it will likely continue to fail. I would look at putting additional support in and likely try to use a short length of Saniflex hose with appropriate fittings between the tank coupling and the pipe in order to deal with the differential movement between the tank and the pipe.
 
Sep 24, 2018
2,549
O'Day 25 Chicago
I used saniflex recently. No issues with stiffness. I would recommend a hacksaw to cut through the spiral wire embedded in it though. I havent used the head so I can only comment on installation
 
Jan 7, 2014
395
Beneteau 45F5 51551 Port Jefferson
My beneteau used 40mm hose. I replaced all the the 1993 original hoses in both heads last year. On the first head I used hot water and soap and eventually managed to "make" the 1.5" fit. On the second head, it was much easier to just replace the tail piece at the thru hull and the y-valve with standard 1.5 inch fittings especially since I was installing a new tank as well.