Identify this part quiz

[EdHouston]

Hi All

I have a mystery part in my head discharge line, see photo, this is in the forward stbd hanging locker just forward of the head compartment. I have no idea what its original function would have been, when I opened it recently (to find a blockage new story) there is nothing other than a rubber gasket at each half. The two halves are held together by a three bolt floating flange. My gut tells me it was at one time a check or non-return valve but again there is nothing inside it now. The boat was originaly configured with an electrosan system long since gone.

Any thoughts ideas or comments will be greatly appreciated.

Ed
S/V Moonlight Mile #110

[dutchie]

Mine guess is it is just a joint to put two hoses of the same diameter together without a restriction in diameter so you don't get a blockage.   

[Henri Hali]

Ed
It looks alot like the check valve on my bilge pump hose. I suspect it may have had a flapper in it at one time.

In my previous Pearson (a 1978  28) I had an Electrosan. It did not have any fittings like this.

Henri Hali
Windrider

[BlameItOnBuffett]

I am about 100% sure Ed is right. They were probably using it (like I plan to) to keep the toilet water that is between the head pump-out and the vented loop from running back down into the toilet. I have heard that getting the rebuild kit for the pump will also help this, but at nearly $100 for a Mark V rebuild kit, the backflow preventer seems a lot mroe economical.