New plumbing Hoses

Aussie Syd · Post by **Aussie Syd** » Mon Jul 05, 2010 11:51 pm

Hi Guys I am presently replacing all of my toilet plumbing hoses 1 1/2inch white hoses with a more thicker guage commercial type as I read here on a recent post, which I thought was a excellent idea. I believe my hoses and the system set up are still the orginals on my 88 sport fisher. E.G 11/2 inch white hose from the toilet to the holding tank via a Y valve for a direct pump out or to the holding tank. When I took the hose off on the direct pump out side I found a plastic one way valve in the hose line and I am not sure why it was there ? or was it there to stop the pump from pumping back up to the toilet as the direct pump out line connected to the out going holding tank line comes in after the pump. Hope this all makes sense. Now I am doing away with the Y valve, and going directly to the holding tank Then pumping the holding tank to a U valve and out thru the skin fitting to sea. Hope I have not missed any thing here or should I still have this one way valve in the system some where? Hope you can help? Thanks Syd

Sean B · Post by **Sean B** » Tue Jul 06, 2010 3:27 am

Hi Syd I recently re-did my original setup in the same way you are. I did not find a one-way valve, and did not install one either. Since the head is below the waterline and connected to raw water one way or another, there always is a danger of siphoning action filling the toilet bowl through the thru-hull and sinking the boat (!) This danger is normally abated with the vented loop in the line to the thru-hull. The vented loop can become clogged with time in various ways however. The one-way valve you found there may have been a past and enlightened Owner's extra safety precautions. Since you will now be plumbed from the thru-hull (with vented loop there) directly to the holding tank (which is also vented), I don't think you need to worry about installing that one-way valve. Also with that type setup, I would imagine that the only time you'll open the thru-hull valve is for a short while to pump out the tank while offshore, and then otherwise leave it closed. Finally, if your boat is the same as mine the top of the (vented) holding tank is above the waterline. All that being the case, there should be no danger of setting up a siphon. With the old setup, if the Y-valve set to direct overboard discharge and the thru-hull necessarily left open, the danger of setting up a siphon and sinking the boat was much more possible. The way you're doing it, I don't think it really is possible anymore. Keep your head through hull closed unless pumping out the tank, and it's definitely not possible. Hope that helps.

BECCA ROSE · Post by **BECCA ROSE** » Tue Jul 06, 2010 5:41 pm

Thats funny you mention the one way valve fitting. I had the joy of digging a "white thing" out of it yesterday in the 90' degree heat. The inside of the valve looks like a joker valve, mine also had a lot of build up in it (hardened waste?) Looking at all my plastic parts yesterday, Y valve, Y fitting, one way valve fitting, they all had a ton of build up inside restricting the flow. I changed the hoses this year, should have changed all the plastic at the same time. Live and learn, another project for the fall.

Aussie Syd · Post by **Aussie Syd** » Wed Jul 07, 2010 1:01 am

Thanks for the reply Sean , Yes I thought I had it right but its nice to have you confirm it, just to be sure. As Bill said after some 20 years its a good idea to change the plastic fitting as well , should smell like a bed of roses when its all done. Hows the rest of your refit going .....? your engines look nice with the re-cond turbo's on top , hope you will post further pics on the rest of your refit soon, will look forward to it. Regards Syd

IRGuy · Post by **IRGuy** » Wed Jul 07, 2010 9:55 am

The most recent email ad I received from BoatUS had an article on cleaning out the scale that builds up on the inside of head piping. Essentially it said to flush the system with vinegar, a mild acid, which dissolves the scale.