T in raw water line

[kingofcary]

Hello all ... the question is associated with my ‘07 Catalina 350. I have uploaded three pics to hopefully illustrate my question.

Pic 1 shows raw water intake line coming up thru top of engine compartment for what I think is a T type of access I guess for winterizing of potentially flushing out since this boat previously was only in warm water. I as new owner will be winterizing.

Pic 2 is a close up to see there is a rather small opening in the top of the T. This fitting on top must have some kind of ‘pressurized’ value to keep it closed when in operation.

Pic 3 is a view to show this fitting has threads to attach something to use it.

My question is has anyone seen this type of thing ? Is it standard on this boat or added later ? How does one use it to flush or winterize effectively.

Thank you ... Dennis

[Wotname]

Looks like an anti syphon loop / valve.

[nigel1]

Vented loop but it's missing the vent cap. See attachment.

[kingofcary]

Wotname ... thanks much it does seem to be anti-syphon loop and valve ! I have not seen one on raw water intake before but i guess it makes sense. Is this typical ?? Also, note the threads ... is this a legit way to get anti-freeze into engine for winterizing ? Thanks again for the good info and insight !! Dennis

[kingofcary]

Nigel ... thanks to you as well ! I took the cap off for pics to show the threads .. note pic 2 has it on pic 3 has it off .. thank s much .. dennis

[Sailmonkey]

That won’t be on the intake, more likely between the heat exchanger and the mixing elbow.

[deblen]

How to winterize a boat engine http://www.cruisersforum.com/forums/...ng-208476.html

[Carver Power]

It is a Anti Siphon valve missing it's cap, He must have had a problem with loosing prime after running??

[jmschmidt]

Pretty much every boat ever built with a water-cooled inboard engine has one of these. It is as Carver Power said.

[HopCar]

Sailmonkey is right, you don’t want one of those in an intake line. They are designed to let air in to break a siphon. You don’t want air getting into a suction line.

[Minggat]

As an emergency bilge pump, some cruisers do tap into the water pump">raw water pump suction. But it is counter productive to not have a valve already in the Tee branch. An emergency means NOW. No time to install the valve and attach hoses.