Galley sink drain valve - replace or clean

[blue-moon]

Galley sink drain valve looks corroded. Should I replace or clean?
If just clean, what to use to clean it? Thanks

[rbk]

Looks like a brass ball valve with incompatible threads threaded onto your through hull. Replace the valve with a proper one with compatible threads or an adapter.
https://www.groco.net/products/valve...flange-adaptor

[Bowdrie]

The above post by rbk is good advice.
Also, that is a lot of metal "hanging in the breeze" off of just a thru-hull fitting.
That reducer bushing in the top of the "T" fitting is bottomed-out and appears to still leak, not good.
That white hose coming into the branch of the T has obviously been leaking, and by the "torqued" appearance of the "tail" of the first hose clamp it is apparent that that clamp has been over-torqued/tightened in an attempt to stop it from leaking.
Issues such as that are sometimes the result of mixing metric and American hose and fittings.
The Groco adapters/valves linked by rbk are a good solution, along with making sure that fittings and hose are matched.