[C320-list] DUCKBILL VALVE IN VENTED LOOPS

[JJ Morrison]

There are 3 vented loops on my boat...one is in the port side cockpit locker and is on the hull side readily visible as two hoses connected by a Marelon loop at the top.This loop is for the raw water engine cooling system. The other 2 are in the head and visible behind the little mirrored cabinets. These two are the anti siphon loops for the head pump and macerator. There is a little Marelon nut on the top of the loop which screws off and contains the rubber duckbill valve. What this does is allows the line to be pressurized but prevents a vacuum from being formed and potentially siphoning water back into the boat. Have a look at this link for an explanation as to why vented loops are essential.
http://www.myboatsgear.com/vented-loops
CheersJohnM1999#574
> From: rick at inflateco.com
> Date: Thu, 15 Aug 2013 05:22:29 -0700
> To: C320-List at Catalina320.com
> CC: c320-list at catalina320.com
> Subject: Re: [C320-list] DUCKBILL VALVE IN VENTED LOOPS
> 
> What and where is this loop and valve, sounds like a potential problem. Want to check mine and buy spare . Don't like sinking
> 
> Thank you and please excuse any grammatical and/or  typographical  as sent from iPhone.
> 
> Rick Portanova | President | CEO
> INFLATE CO, INC.
> www.InflateCo.com
> 949-340-0104 Office
> 
> 
> On Aug 15, 2013, at 4:48 AM, JJ Morrison <sail-ability at sympatico.ca> wrote:
> 
> > I had asked about procuring duckbill valves and I was not able to get them. Need to buy the cap with the valve in it...$13 CAD from Forespar. Related I had taken the duckbill out of the vented loop in the exhaust system to see if the Chandlery had them. We subsequently went out on the boat and the bilge pump came on and wouldn't shut off, water was pouring in. I tore the boat apart looking for the wet spot...nothing. I then opened the port cockpit locker and everything was soaked and a vicious stream of water was being pumped into the boat out of that  vented loop. The engine was shut down and the stream stopped of course...duh!! Luckily I had that tiny rubber  valve in my pocket and put it in place.There's a lesson here!I'm in the process of replacing all three vented loops with new ones. The caps with valves are not expensive but just the rubber can't be more than 50cents!CheersJohnM1999#574                         
>