Raw Water Strainers: I have questions...

[Phr3d]

Boat has none for salt water.

• Raritan shows one in the diagram for their toilet.
• Was mentioned as something to check if it is limiting flow in the raw water cooling pump plumbing for the engine.

So that's two (would there be more somewhere?). We have had no issues of plugging that I know of. It has been interesting seeing the salt water flush complete with "things' in the water (and at night it is fun to watch the bioluminescence). I did install one between the fresh water tank and pump (the replacement pump instructions made this suggestion) which almost seems funny in terms of what is coming into the boat, currently unfiltered.

The question is, "How did other people address this?" with details about where mounted, above the waterline, below the waterline, what brand, style, pros and cons, etc.

 

[peaman]

A strainer on the raw water intake for the engine is pretty standard to prevent sea grass and other stuff from clogging the engine cooling circuit. The strainer should be installed vey near the water line so it can be serviced without allowing a lot of air into the system.

A small filter with a clear bowl is a good idea in the house pressure water system to protect the pump from stray stuff and to prevent bits of biology from circulating.

A strainer in the sea water flush intake for the head, I guess, is optional, but I don't think it's common. Stuff comes in, stuff goes out. But if present, installation below the water line would make servicing easier.

Any other pumped intakes, as for water cooled air conditioning or refrigeration, or water maker should be protected with a serviceable sea strainer.

 

[Prairie Schooner]

Boat has none for salt water.

• Raritan shows one in the diagram for their toilet.
• Was mentioned as something to check if it is limiting flow in the raw water cooling pump plumbing for the engine.

So that's two (would there be more somewhere?). We have had no issues of plugging that I know of. It has been interesting seeing the salt water flush complete with "things' in the water (and at night it is fun to watch the bioluminescence). I did install one between the fresh water tank and pump (the replacement pump instructions made this suggestion) which almost seems funny in terms of what is coming into the boat, currently unfiltered.

The question is, "How did other people address this?" with details about where mounted, above the waterline, below the waterline, what brand, style, pros and cons, etc.

This is what we found in our strainer a couple years ago. I wasn't in the habit of checking it regularly. The raw water pump is forced to act as a macerator for whatever goes through. And the passages in the heat exchanger, especially, aren't very big. I'd say a strainer is a must.

We've since upgraded and relocated it. Discussion about this starts at post #96:

Coolant Conundrum/Exhaust Riser Replacement [Master Thread]

Ken, how has your thinking about these systems developed in the past four years? Solidified? Changed? Most of what I know about exhaust systems in general came from this excellent article: https://goodoldboat.com/cool-quiet-and-trouble-free-exhaust/ Like the article says, many of the...

ericsonyachts.org

We went with what and where Nick did with his installation.

 

[Christian Williams]

We have a Groco strainer for raw sea water. Marina del Rey has no sea grass, and Santa Monica bay little vegetation, so it rarely picks up any glop. It's good to have engine cooling water strained, but here might be optional.

Diaphragm bilge pumps absolutely need filters for bilge water, whereas submersible pumps seem OK without.

As for 'sanitary" filters for the fresh water system, as in home products advertised with exclamation points on TV, forum wisdom notes that they are bacteria traps unless the filters are changed with great frequency. I have one, fail to check it often enough, and wish I didn't.

 

[windblown]

Groc

We have a Groco strainer for raw sea water. Marina del Rey has no sea grass, and Santa Monica bay little vegetation, so it rarely picks up any glop. It's good to have engine cooling water strained, but here might be optional.

Diaphragm bilge pumps absolutely need filters for bilge water, whereas submersible pumps seem OK without.

As for 'sanitary" filters for the fresh water system, as in home products advertised with exclamation points on TV, forum wisdom notes that they are bacteria traps unless the filters are changed with great frequency. I have one, fail to check it often enough, and wish I didn't.

Groco strainer for raw lake water intake is the norm here. We clean It annually, even though it doesn’t need it. A separate strainer (just like the Jabsco that Prairie Schooner shows in post #3) is on the hose between bilge and diaphragm pump that we clean out at least weekly during the summer, and another Jabsco strainer (same model) is on the fresh water system, after the manifold and just before the fresh water pressure pump, needs cleaning once or twice a year In our world.