Raw (Seawater) Strainers for HVAC etc. use

[donw_s11]

I'm curious what other people are using for raw water strainers on saltwater boats. The reason I ask is that I've got a stainless mesh strainer in front of my AC H20 pump that has holes in it one year after installation (See pic).

I'd like to replace it with something that will last at least five years or so between replacements if possible to avoid having to try to find parts while out in the boonies.

Groco makes a bronze strainer body with a Monel strainer ($$$), which would be worthwhile if it really lasts. Does anyone make a plastic strainer that lasts?

Suggestions?

Don W.

[colemj]

I have 4 similar strainers on our boat and after 9 years, only one of them had a corrosion issue. Mine didn't look rusty like yours, it just was eaten away in a couple of places. The others are perfect. I can't remember offhand if ours are Groco or Sherwood, but I think they are Groco. You can get replacement strainers for them cheaply. Maybe you just got a bad one?

Mark

[markpj23]

I have these Forespar units for everything - genset, main engine, A/C units, everything. Plastic interior baskets. The only complaint I have is that the lid supports (underneath the threaded knob) are plastic and you can break them off if you crank down on the cover nut too much. Else they are maintenance-free.

[AnchorageGuy]

That ain't no sea strainer that's a water filter.

[Pblais]

If it's below the waterline that sure is no sea strainer. Almost all filters for AC I'm aware of are below the water line. As Chuck notes it's a prefilter from you fresh water tank before it goes to the pump. It's just a toy strainer to protect the pump. You need a much larger one when you get into jelly fish they clog too easy. It's also plastic. You should be looking at what you find on the raw water filter for the engine would be more appropriate. The Vetus raw water filter I have would not work for the AC but is fine for the engine as the top is above the water line. The Forespar looks like the Vetus. I would not use one below the water line. if you break the plastic cover you will sink if it's below the water line.

I also find a March pump is much more relaible than most others. Cheap Cal pumps suck. The March pump head is made of nylon and can be replaced. A Cal pump dies and you toss it and much sooner.

[GordMay]

As indicated, the previously pictured are "toy" strainers for already clean water.
This is a real seawater strainer:

[donw_s11]

Churk, Paul, and Gord

Well, right now its not much of a filter either. None the less, this is the "filter" that the PO installed with the new AC shortly before I bought the boat. It was installed below the waterline with a short hose to a thru-hull, and inline before the AC H2O pump. I believe that it probably came as part of the installation kit with the AC.

As you can see, I didn't think much of the installation--or the longevity of the device (which is why its currently setting on my desk instead of installed in the boat). I'd like to replace it with something better (he says hopefully), and would like to hear suggestions, and other peoples experiences with the devices they have in their boats.

BTW, my boat currently does not have a strainer in the cooling water loop for the raw water cooled engine (yanmar 3HM). Should it have?

Don W.

[donw_s11]

Mark,

Groco makes both stainless strainers, and monel strainers. Do you have any idea which yours are?

I suspect that this one was 304 stainless or similar based on how quickly it corroded.

Don W.

[coot]

Originally Posted by donw_s11

I'm curious what other people are using for raw water strainers on saltwater boats. The reason I ask is that I've got a stainless mesh strainer in front of my AC H20 pump that has holes in it one year after installation (See pic).

The picture you posted looks like a Groco with the stainless steel screen. Groco also makes a plastic screen that fits into the same strainer body. The holes in the plastic screen are larger -- about the size of the holes in the strainer that Gord shows.

[colemj]

Don,

I don't know whether mine are monel or SS. If they make monel, why not just buy a replacement screen?

Mark

[markpj23]

Originally Posted by donw_s11

BTW, my boat currently does not have a strainer in the cooling water loop for the raw water cooled engine (yanmar 3HM). Should it have?

ABSOLUTELY!!

[donw_s11]

Originally Posted by markpj23

ABSOLUTELY!!

Hmm... That's good to know

Don

[AnchorageGuy]

Don, Look at the strainer set up on your engine then go to your local Marine supply store and find one just a bit smaller and that will acomodate the size hose barbs you will need for the AC. Install it just after the thru hull valve and you are in business. Be sure to blead the water to at least the discharge end of your AC unit so you don't get air locked.