Sink Drain

[Team118]

Hello everyone.

As I wrap up my refit, I am left reinstalling the galley. I removed one of the sinks and refinished the counter with just one sink.

The old plumbing set up was such:

There was a drain line from the head sink that ran back to the galley.

The galley had 2 drain lines, one for each sink. The sinks were joined via 2 tees which run to the through hull 1" ID. The head sink teed into this line prior to running into the through hull.

The interesting thing was there was a tee in between both sinks. A seperate line was installed to act as a vent. This vent was tied to the top on the siphon break that is installed for the engine coolant system.

Do I really need to install a vent to allow the sink to drain easier, or can I just tee the head sink drain line into the galley sink drain line before they connect directly to the through hull?

This is old drain from the port sink on it's way to the center sink

The red hose goes up where it is clamped to the top of the siphon loop.

Which is here...

Thanks for any input!
Chris

 

[Bad Obsession]

That is an odd setup and totally different from my Catalina 30 MKii.

My set up the two galley sinks drop straight down to a T which then flows into the through hull almost directly under the sink. The pump out for the ice box ties in there as well. I tied in a drain from the sump pump that I installed as well. The only thing on a vented loop is the sump pump since it is below water line. The sinks and the icebox don't have a vented loop since they are above the water line.

The head sink drains straight down to a through hull that is accessed through a small door on one of the bulkheads. Technically, it is underneath the V-berth but you can gain access to it through the head because you are supposed to shut the though hull each time you use it. The head sink also is a straight shot to the through hull.

My head intake ties into the head through hull. Technically, you are supposed to add a vented loop to this set up. The vented loop will prevent the siphon.

I can't imagine tying the head sink into the galley sink through hull. That is a very long run and I don't think that the sink would drain properly.

If you are doing this work and ever have any intentions of using the shower in the head, I strongly suggest that you put a sump box down in the bilge. The measurement is 8" by 5" to fit. You run the hose from the sump box through the side of the bilge, out past the engine, into the galley counter, through a vented loop, and then back down and tie in with a T fitting right by the through hull into the hose. The wiring is also pretty simple as I tied it into the Fresh Water Pump. The sump box has a float switch which comes on when the sump gets a certain amount of water in it.

 

[Team118]

I appreciate the response! I knew this setup was strange, especially since the siphon break has a hole barely larger enough for a flea to get past.

I think I'll leave the head sink unconnected for now and just run the lone galley sink to the through hull right below it.

That should be ok.

 

[Bad Obsession]

Is there a through hull in the area of the head. I would think that it would be odd for one not to be there.

The sink drains above water line so a vented loop would be bad for drainage on the sink and it wouldn't allow the sink to drain right at all. The straighter the shot to the through hull the better. If there is a lot of bends and other things it is just an area for crap to accumulate and cause the sink to drain even less effective.

You should be able to find a plumbing diagram in your owners manual. If you can't find one check Catalina 30 Owners Association. If you can't find it there email Catalina.

As far as the sump pump set-up...let me attempt to diagram what the set.up looks like.

 

[Paul17512]

Plumbing

Hello,

I have a 79 MKI that is plumbed similar to yours.

The head sink Ts into the Galley sinks just prior to running out of a single sea cock below the sinks. It sounds like a long run (from the head sink) but this works perfectly fine.

Also, The "vent line" which runs from you engine cooling water to your sink drain is not intended to vent the sinks for better draining. It is there to break the siphon (should one happen) when the engine is not operating to prevent you from flooding your aqua lift muffler an and engine through the exhaust.

You absolutely need this line installed and you need to make sure it is free of any obstructions. take it off and blow through it.

If you want to remove that line you can install a vented loop (see link) and eliminate the line.

http://www.westmarine.com/webapp/wc...RL=true&storeNum=11&subdeptNum=70&classNum=77

good luck.