Ball valve - where from?

[Mikedefieslife]

I need a 38mm pvc ball valve to attach in between my holding tank and the through-hull.

The valve will be used prevent the hose being full of sewage when the through-hull is closed.

Where do you buy these from I've not seen any in local stores or chandlery and an online search doesn't turn up much other than valves for 40mm pipe (which is the wrong size and of course doesn't have hose fittings).

Whilst we're at it. I'd also like a three-way diverter valve with both 25mm and 38mm attachments. Again I've not seen these available either.

 

[Yngmar]

Tru-Design ball valve should do, with a 38mm hosetail on each end. Widely available online, LeeSan is one of the distributors.

For the diverter valve, several choices available too, Whale makes a good one for example, and I think Tru-Design makes one as well now. I don't think they exist in mismatching attachment sizes like you want, but adapters are available. Obviously reducing at an outlet would constantly block it, but going up a size at an inlet should be fine.

 

[duncan99210]

Could try looking here https://www.forespar.com/products/boat-marine-plumbing-ball-valve-thru-hull.shtml . Their valves are threaded to accept hose tails to match the hoses you require. Not sure you're going to find a valve that comes as a unit with hose tails fitted in the size you want: you need to buy valves that will take hose tails in the sizes you need.

 

[Tranona]

It does not have to be PVC. An ordinary metal valve, either stainless or DZR would be fine, and in fact a standard plumbing valve would also do as it is not immersed in salt water. The size will be 1 1/2" BSP which takes a 38mm hose with the appropriate hose tail.

Although I fitted such a valve on the first holding tank I fitted it is not common to do so as if you use proper sanitation hose there is no problem having it full of waste. If it is a gravity tank then make sure you have access immediately above the outlet and the valve so that you can deal with the almost inevitable blockages if you leave the tank with waste in it for any length of time. don't ask me how I know, and was grateful for designing the tank to have this access.

 

[Mikedefieslife]

If you leave sitting sewage in proper sanitation hose it will eventually permeate. Even the sailing magazines say this. I know because my hose is only a year old and being as my tank is gravity fed sewage sits in it until I open the through-hull.

A good quality rubber hose might have held up better (mine is a thick walled pvc sanitation hose), but you can't often buy quality kit in the likes of Spain, Italy and especially Greece, so no £30 per metre raritan hose for me.

I have a macerator toilet, and no paper is flushed, so thinking of changing (at some point in the future - not now) to 25mm at it will mean it will take just 1.5l to clear the hose to the holding tank as oppose to almost 4l for 38mm hose. Recently used a friends Jabsco electric and it had a 25mm hose and worked well.

The Tru-design valves looks nice (if pricey), not they it will be seen. Seems SVB stock them. Incidentally, I was just looking through the SVB catalogue when I started replying to this.

 

[Tranona]

You are right, pvc will smell, but butyl will not.