Fitting vented loop on macerator discharge

[Chuck]

I am adding a vented loop to the discharge hose from the macerator in my Catalina 36 (per Peggy's suggestion). While the discharge hose to the macerator is the standard 1 1/2 ", the hose from the macerator to the thru-hull is 1". I have not been able to locate a 1" vented loop, only 1 1/2 or 3/4. Is there a prefered way to connect the loop to the this hose? Also, should I run a hose from the top of the vent in the vented loop to my vent from the holding tank? It seems like I would want to capture any leakage from that vent.Thanks for your help.Chuck

 

[Dick McKee]

Chuck or Peggy, you goat help me on this one...

I follow this board and am always looking or something I'm doing wrong, and this post got my attention. Why would we want a vented loop on a mercerator discharge line when the line runs from the tank to the mercerator and then thru a thru the hull valve as I thought was required by the USCG. The only time my valve is open is when I'm running ther mercerator. As soon as I shut off the power to the pump I close the valve and log the discharge. Am I missing something here??

 

[Peggie Hall/Head Mistress]

Two ways to do it...

You could get by with just a high loop in the line. It won't stop a siphon, but it will prevent your tank from filling up with seawater if you leave the seacock open. Or--you can use 1.5" vented loop by using 1" x 1.5" reducing adapters in the line. Personally, I'd just go with the high loop in the line.To answer your questions about potential leakage from a vented loop--there shouldn't be any. There should be a one-way air valve in the nipple at the top of the loop that only lets air IN, not out. Only when the valve is missing or it's failed should a vented loop squirt anything.To answer Dick's question--what's the point of putting a vented loop after the macerator: it's a fail-safe device. No, you don't plan to leave the seacock open, but human beings are fallible, and erring on the side of caution makes it a LOT harder to get into trouble than relying on human fallibility.

 

[Chuck]

Thanks - Reason for concern

Thanks for the input - my concern was that if the valve is open, and the macerator off, can the water pass the macerator and fill the holding tank?Chuck

 

[Dick McKee]

Thanks Peggy...I forgot about the human element..g

Prepare for the mistake and it porbably won't happen!!

 

[Peggie Hall/Head Mistress]

Yes, water most definitely CAN

seep through the macerator into the tank. There are no one-way valves in a macerator. And, before you ask--No, you should not use a one-way valve instead of a loop...it'll restrict the outward flow from the macerator when it's running. Besides, valves fail. The whole point of installing loops is a passive system that protects your boat from sinking in the event of human error or mechanical failure. With that in mind, be sure to double clamp all hose connections too.