Raw Water Strainers

Raw-water strainers are most often associated with the cooling systems of inboard engines. Every boat that brings aboard outside water to cool the engine, whether the raw water flows through the engine or through a heat exchanger, needs a strainer to prevent grass and other solids from reaching the pump. All raw-water intakes on a boat should also have an in-line filter. This includes the cooling water inlet for a generator or onboard air conditioning, a refrigerator heat exchanger, a live well, or a deck-wash pump.

The benefits of a strainer for the intake line supplying the head and the raw-water spigot in the galley are nearly always overlooked. Marine toilets often stink because of grass lodged in the inlet-water passage under the rim, and a filter eliminates this problem. The merit of filtering water flowing into the galley sink shouldn't require explanation.

Plumbing a raw water filter is simply a matter of inserting it into the line connected to the seacock. Raw water filters must be fastened securely to a bulkhead and the location should be as close to the seacock as practical. The hose connection from the seacock to the filter should be as short and straight as possible. The outlet hose to the pump should likewise not have extra length or bends.

The easier a strainer is to clean, the more often it will get cleaned. Look for strainers with spin-off or lift-off caps with lift out baskets. No tools should be required to service the filter, and if it is mounted above the waterline, it won't even be necessary to shut the seacock to clean out the basket.

For more information or to discuss your particular installation needs contact AhoyCaptain.com. We'll be glad to help.