Non Return Valve for heads?

[Refueler]

Just touching on the subject of fluids to clear pipework etc.

For years I have used two fluids (ignoring the obvious) ... for passing through my boat bogs.

General - I occasionally put Windscreen Washer fluid through - the kind that has 'lemon juice' in ... its not real lemon ,,, but sure you know what I mean. It can lubricate the system and also help to reduce scale build up.
I used to use Cooking Oil - as advised by some bog manufacturers to 'lubricate' the seals etc. But stopped in favour of Washer fluid ..
Winterisation - Either winter grade Washer fluid - we can get it to -35C here ... or Anti-Freeze - again -35C .....

If I've needed to really shift scale .... then here we don't have Vinegar as in UK ... we have various Grape and other based Vinegars - but the one that removes scale - concentrated spirit Vinegar that has put people in hospital !! To use on your chips - it needs serious dilution ......
Boy does that fizz up scale !!

 

[wonkywinch]

An update. I removed hoseclips and the toilet joker valve, all looked OK. Using a small rodding wire brush, it was stuck at the non return valve.

Removing that whilst holding a vacuum hose on the external vent to ensure contents would go up into the holding tank rather than down into the nappies I'd placed around the pipework.

There was a solid plug of toilet paper stuck in the one way valve which was also a joker type. This was aggravated by a lot of limescale around the outlet. This had built up in the restricted area where the 1.5" outlet dropped down to 1". Even though the valve had screws to open it up for maintenance, Whale don't sell the joker valve on it's own so I bought a new valve.

The instructions and a sticky label on the valve stated that if using a 1.5" pipe, then the 1" spigot should be cut off. Our boat system had 1m of 1" into the NRV then 1.5" up to the tank. Beneteau clearly didn't follow the valve makers guidelines and left the 1" outlet such that it sat inside the 1.5" pipe causing unnecessary restriction for the joker outlet and place for limescale to collect.

This friction caused paper to stick to the walls and result in the blockage.

New valve fitted with 1" tail removed, new joker to the pan outlet for good measure and it's flushing better than it ever did.



Stock picture of dual 1/1.5" valve prior to mod removing 1" tail on 1.5" pipe side.

Pipe internals looked OK, but a winter job may be to replace the soil pipes as they are easy to get to.

 

[Refueler]

Not unusual for builders to take easy route ....