What is this called.....

[Kamalolo]

Trying to replace the white cap thing......we think it has to do with the toilet smell inside the boat.....seems to be an exhaust or something to a toilet line..

(I'm completely clueless to the terms lol)

Or any other ideas to why it smells when we pump toilet to black water tank and seems to come from the general area of what's pictured......

[Alan Mighty]

Lots a lot like a Scot Marine vacuum breaker (or siphon breaker).

See; SCOT DIVISON OF ARDOX - -VB38 SCOT VACUUM BREAKER 3/8" FPT | MMIMarine.com

Is that not what the label reads?

[Alan Mighty]

Your Scot Marine vacuum breaker needs annual testing and cleaning.

Two parts.

Uppermost is a nylon perforated cover. It houses a blue poppet and a stainless steel spring.

Below that is a second nylon fitting, that is attached to your sewage line.

The stainless steel spring, above the poppet in the perforated cover, holds the poppet closed.

Test by removing the breaker (don't round the nylon hexagon) and attempt to blow air through the hexagon end. No air should escape. If you blow through the perforated cover end, air should pass through easily.

Lime scale and crap can block the poppet. Clean: Soak in warm freshwater. Add vinegar to the water if necessary to remove lime scale.

Do not try to pry the blue poppet from the perforated cover.

[Alan Mighty]

Once you've cleaned and tested your Scot Marine vacuum breaker, message a moderator and ask them to move this thread to Engineering & Systems/Plumbing. That's where it belongs, not in Our Community.

[Alan Mighty]

The original manufacturer is the Scot Pump Division of Ardox.

They also make stainless steel loops on which the vacuum breaker can be mounted, making a "vented loop".

You should be able to see the vented loops in the bottom right hand corner of this page on their website: http://scotpump.com/#marketmarine

You should be able to buy a new vacuum breaker (check the size, I think they made at least two sizes) for many marine supply stores (not just MMIMarine.com). You'll find some variation in prices.

Here's another retailer: Boatswain's Locker - Scot Vented Loops and Parts

[Alan Mighty]

The odour to which you refer is just a cocktail of chemicals, dominated probably by two: indole, and skatole. If you speak Greek, you'll understand the significance of the name of the latter chemical.

Human brains are wired to detect those two chemicals in relatively low concentrations. Got a lot of social significance.

[Alan Mighty]

Looks like I was in error when I wrote that Scot Marine vacuum breaker was made of nylon.

http://www.cruisersforum.com/forums/...ml#post1950822 reckons it is made of Delrin, a high molecular weight polyoxymethylene.

Sorry about misleading you.

Your vacuum breaker might only have one part (not two) of Delrin. You may have only the perforated cover, which screws directly onto some fitting, instead of having a second piece of Delrin below it.

[Davidhoy]

Originally Posted by Kamalolo

Or any other ideas to why it smells when we pump toilet to black water tank and seems to come from the general area of what's pictured......

Often the odor comes not so much from #1 or #2, but from the supply water. If you're flushing with sea water, the intake water in the supply line sits stagnant for a while between flushed. Micro-organisms in the water die and decay, resulting in odor when that water is drawn into the bowl. If you're using the head regularly this should not be that significant of an issue.

-David

[wiekeith]

Does the word in white letters on the blue pipe really say what I think it might...

[Privilege]

The issue might not be your vented loop but rather your hose. It looks as though you have black exhaust hose for your toilet flush? The smell will permeate through the hose. To find out if this is the case, wet a rag or towel with hot water and wrap it around the hose. After a few minutes when it has cooled, unwrap it and take it outside. If you can smell the smell on the rag, your hose is the problem.

[gwbull]

Agree with Davidhoy. Odor just like black water, but actually from saltwater intake and hose to toilet. White vinegar immersion will stop this pretty quick, and if you can find a way to clear your thru-hull, more's the better. Try it before disassembling everything. And be advised... vinegar is magic. In colonial days it was the antiseptic of choice and effectively so.

[Redline452]

Originally Posted by wiekeith

Does the word in white letters on the blue pipe really say what I think it might...

guess so... the SHIelds has hit the fan

[Kamalolo]

Originally Posted by wiekeith

Does the word in white letters on the blue pipe really say what I think it might... [emoji3]

[emoji90] [emoji13]

[Kamalolo]

Originally Posted by Alan Mighty

Lots a lot like a Scot Marine vacuum breaker (or siphon breaker).

See; SCOT DIVISON OF ARDOX - -VB38 SCOT VACUUM BREAKER 3/8" FPT | MMIMarine.com

Is that not what the label reads?

I believe your right....don't mind the price either. Thank you

[Kamalolo]

Originally Posted by Alan Mighty

The original manufacturer is the Scot Pump Division of Ardox.

They also make stainless steel loops on which the vacuum breaker can be mounted, making a "vented loop".

You should be able to see the vented loops in the bottom right hand corner of this page on their website: http://scotpump.com/#marketmarine

You should be able to buy a new vacuum breaker (check the size, I think they made at least two sizes) for many marine supply stores (not just MMIMarine.com). You'll find some variation in prices.

Here's another retailer: Boatswain's Locker - Scot Vented Loops and Parts

🖒 thanks for ur knowledge