Sea strainer on outflow side of raw water pump

[Valiant173]

I have a 1977 Westerbeke 40, and its been great. Any thoughts on putting a sea strainer on the outflow side of the water pump">raw water pump so that it would prevent impeller bits from clogging the heat exchanger? It would also provide a quick visual of impending impeller failure.

I've thought about installing one but all sea water strainers I've seen have been on the suction side of the raw water pump. Would one of those work? Or would it have a shortened life (read inopportune failure) because it is installed on the pressurized side of the raw water pump?

Just curious.

[enrigenna]

On my Lagoon 500 the Onan 11KW generator suffers of short lived impeller, forcing me to change them every 200hrs when lucky
I installed a strainer between the raw water pump and the heat exchanger tired of having to fish impeller peaces out of the exchanger.
Has been a year and so far no problems, still have to change impellers way too often, but this way I can see the peaces in the bowl of the strainer and change the impeller before it fails.

[DeepFrz]

Jedi did exactly that as well on his main engine.

[rwidman]

I'm sitting here trying to picture it but I'm pretty sure that's how my Volvo TAMD41P is built. From thruhull and seacock to pump and the to the strainer.

[DeepFrz]

It should run from seacock to stainer to pump. The added small strainer after the pump is mostly to catch pieces of impeller should they break off.

[Valiant173]

Many thanks to you all who've posted a reply. I guess now I'll be searching for a suitable sea strainer.

[Stu Jackson]

If it was for a generator, I'd do it.

For my main engine, I'd just swap the impeller out regularly.

[deblen]

Originally Posted by Valiant173

Many thanks to you all who've posted a reply. I guess now I'll be searching for a suitable sea strainer.

I did this 2 yrs ago,after removing & cleaning rubber bits out of my heat exchanger.
I have a Groco between seacock & RW pump intake & installed a Jabsco? plastic filter,picked up on ebay $40,between RW pump output & engine.
Will be much easier to clean(5min.),than half a days work to clean HX.

[Chuck Hawley]

Sounds like a reasonable idea. I can't believe the pressure on the engine side of the raw water pump would ever cause a problem to a modern strainer (Vetus, Forespar, etc.)

Chuck

[deblen]

Originally Posted by Chuck Hawley

Sounds like a reasonable idea. I can't believe the pressure on the engine side of the raw water pump would ever cause a problem to a modern strainer (Vetus, Forespar, etc.)

Chuck

I don't really know how much pressure a RW pump can push,if it was choked off by a plugged strainer,exh.ell,etc.
Perhaps someone will tell us.

[osirissail]

Something like the strainer below could be plumbed into the engine's R.W. pump output side to catch the impeller vane bits - hopefully without any resistance buildup except when the R.W.pump impeller vanes actually get into it. This strainer comes in just about all sizes and is used in the boat's potable water system.

[rwidman]

As I posted above, here is a photo of my stock Volvo TAMD41-P. Seacock to pump to (stock) strainer.

[Terra Nova]

Nice, clean engine room.

[enrigenna]

the strainer in osirisail post is exactly what I installed, and works great.
Only thing is the mesh a little too fine, after a while some foul grow on it, it doesn't reduce the flow, but it is difficult to see the impeller bits inside.
I plan on replacing it for bigger one, at the end it is just to avoid big chunks of rubber to clog the exchanger, but still haven't found it, I'll try to make one ...

[rwidman]

Originally Posted by Terra Nova

Nice, clean engine room.

Thanks. I try to keep it that way. A clean engine room makes it easier to find problems early and of course it minimizes tracking dirt and grease into the boat.