Thanks

James

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

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

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.

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

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 😇