jalbery
  • jalbery
  • Advanced Member Topic Starter
2020-08-28T13:38:54Z
Does anyone know the sizes of the ball valves for the heads inlet and outlet?

Thanks
James
Morning's Minion, Parker 275, No. 1
geoff.sheddick
2020-08-28T14:03:30Z
3/4” (19mm) and 1.1/2” (38mm)
The fact that you are asking this suggests that you may not be familiar with the essentials of through hull fittings?
If you are, then you will already know NOT to buy plain brass from a domestic plumbing supplier, likely stamped CW617N, but only to buy DZR from a marine source - it will be stamped CW602N.
Bronze is best, but you will not like the price ...
One good, highly reputable source, with clear explanations, is ASAP-suplies.com
See also Vyv Cox coxeng.co.uk - metallurgy - brasses and bronzes
Geoff Sheddick
Parker 27/146 "Stroller'
jalbery
  • jalbery
  • Advanced Member Topic Starter
2020-08-28T15:09:45Z
Thanks Geoff. I was aware of the difference between the marine and domestic types but it's always worth checking. I know I need to replace them and wanted to check the size without having to make a trip to the boat first.

Although it may not be practical this time, I was wondering about changing to the Marelon plastic types. Do you have any views on the benefits/drawbacks of those?

Thanks
James
Morning's Minion, Parker 275, No. 1
geoff.sheddick
2020-08-28T17:45:42Z
Advantage = very strong, non-corrosive, inert, (ie no risk of contributing to electrolytic or galvanic corrosion)
Diasadvantage = bulk (ie physically much larger, may not retro-fit), can bind if left unmoved for e tended periods (ie not periodically opened/closed)
My knowledge base = ret’d global marine toilet product marketing specialist so had to have understanding of associated installation products.

Geoff Sheddick
Parker 27/146 "Stroller'
DickG
2020-08-30T18:37:04Z
I have looked at the Trudesign valves, and with the spacing of the fittings on Dark Star they will fit in. I'd be interested in Geoff's thoughts on Trudesign v Marelon.

While ASAP is a good source, it is worth paying close attention to the detailed spec of each product. Some bronze valves seem just to have bronze bodies. ASAP don't always include the material used for the stem. Ideally the spec would detail the material used for body, stem and ball.

Regards

Dick
Dick
Dark Star P275 No 36
geoff.sheddick
2020-08-30T20:03:35Z
Having retired a few years ago, I’m no longer fully up to speed, but Marelon originated with RC Marine in New Zealand, Forespar (USA) got involved, but I believe that True Design has superceded RC Marine. True Designs product range is quite clearly derived and d3veloped from RC Marine’s original offerings.
And your quite right in spotting that the stem is a critical component in the ball valve, and that a “bronze body” can hide a
multitude of sins inside itself 😇

Geoff Sheddick
Parker 27/146 "Stroller'