Gate valve material

[PeterV]

I’m looking at my sea cocks. The two in the heads are Blake’s valves and are fine but the two sink drain valves are both gate valves to BS5154/B. They seem in good condition and I know they’re bronze, but is this a bronze I can expect to last well please?

 

[Tranona]

Don't think the standard will help on the material. Gate valves are made in bronze or brass. Would guess if they are original and still there, will be bronze. However, nobody uses gate valves these days for through hulls for 2 reasons, First you cannot see whether they are open or closed and second even if the bodies are bronze the innards are not and they have a habit of either the stem breaking or the gate seizing. Best to replace them with ball valves in DZR, bronze or composite plastic.

 

[vyv_cox]

I’m looking at my sea cocks. The two in the heads are Blake’s valves and are fine but the two sink drain valves are both gate valves to BS5154/B. They seem in good condition and I know they’re bronze, but is this a bronze I can expect to last well please?

It is very easy to tell the difference between brass and bronze, they have totally different colours. Americans call bronze 'red brass' for a reason (not that I support that reasoning ?) Compare the colour with a plumbing compression fitting. Lots of examples on my website.
However, as Tranona says, gate valves are a liability on a boat. They regularly fail closed when the actuator snaps. Not too onerous on a galley sink but possibly catastrophic on an engine coolant inlet.

 

[PeterV]

Sadly, although they work and the body and gate look good, the gland nut has just fallen apart when I tried to undo it, it’s pink all the way though so obviously that part wasn’t bronze! So it will be a replacement any way. And yes, I thought they probably are original.