Sea Cocks
What Type of Seacock do You Have?
Gate seacocks are multi turn to open and close with the mechanism screwing down a “gate†to open or close the outlet/inlet.
Ball seacocks have handle with a 90 degree open close mechanism moving a close fitting “ball†with a hole through it for inlet outlet. The hole is in line with the outlet for valve open and at 90 degs for closed.
Hence can tell at a glance when ball types open but generally need to rotate the handle on gate types to find end stops. It is recommended that you don't leave the the handle rotated hard against the open stop in case it jams. Find the end stop and back off a little.
It is also recommended that you execrcise seacocks (especially gate type) every time yo go on board.
Cone type Seacocks - Blakes Style. There are other sea cocks that have handles that only move 90 degrees. In particular Blakes type sea cocks, which Westerly fitted to Centaur heads inlet and outlet, also have handles that operate over 90 degrees. They are not ball valves but a form of cone valve and they differ from ball valves in that the handle is on the top of the valve not on the side as in a ball valve. The difference is very obvious.Blakes seacocks need greasing every year to keep them from leaking so it is important that you identify them.
Ball valveinfo here: [1]
Gate valve info here: [2]
Blakes web site here:
What Type of Material is your Seacock Made of?
Brass
DZR
Bronze
Marelon
