Seacocks
Gate valve seacocks have a flower shaped tap to open and close; not so clear when you have to close it in an emergency.
Blakes seacock that has not been properly maintained; this has failed due to corrosion in the inlet pipe.
Seacocks are designed to control the flow of water through the hull of your boat and into your on-board water systems. They are vital components in the cooling system of your engine and other plumbing installations such as heads and fresh water systems.
Seacocks are made of various materials which can corrode and fail if not serviced and maintained on a regular basis. We always advise boat owners to have their seacocks serviced annually to ensure they are working properly and not jeopardising the integrity of the hull.
Seacocks can fail in freezing conditions so if your boat is layed up ashore for the winter it is important to have the seacocks serviced or ‘winterised’ to ensure they do not crack or become damaged if the temperature drops below freezing.
Different types of Seacocks
There are many different types of seacock. Some vessels may still have old fashioned gate valves; these are not as safe as modern seacocks as the "on" and "off" directions are not as obvious as on new seacocks. Gate valves were designed to interrupt or stop the flow of low-pressure systems. More modern seacocks are designed to stop high-pressure flows and are less likely to fail. If we find gate valves in a vessel we will advise that they are replaced with ball valve or a Blakes seacocks.
Blakes seacocks can be expensive but if serviced regularly will outlast most other types. We can replace damaged Blakes seacocks like for like if required.
Hattersley ball valve seacocks are Lloyds approved and are easy to service. We would advise most boat owners to have these seacocks and would use these to replace older gate valves.
Servicing Seacocks
Seacock servicing should be part of your annual maintenance schedule. You can request a service on your haul out form. It is important to get any problems checked out by a professional who knows what they are looking for.
We usually service seacocks when the vessel is out of the water so it is possible to externally check skin fittings for corrosion as well as accessing the internal components.
On ball valve seacocks, we use a specialist spray to keep the ball component lubricated and protect it from corrosion. We apply this from both sides if accessible.
Blakes seacocks require a little more attention. The barrel mechanism in a Blakes Seacock can become seized if left in one position over a long period of time without proper servicing.
We will remove the barrel and clean it to remove any old grease. The components are visually checked for corrosion before having a small amount of grinding paste applied to seal the top of the barrel and grease to protect and lubricate the lower portion of the barrel.
