Holding Tank Plumbing

TBeyer · Post by **TBeyer** » Tue Jan 31, 2006 10:17 am

I have a few basic questions in regards to holding tank plumping. First off the boat is a 1977 Paceship PY26 that we pretty much gutted and rebuilt last winter. One thing we did not do was install holding tanks for galleyand head sink, we used flexible 5 gal tanks for the season along with porta pot. This winter I want to install holding tank for galley and head sink with the addition of head tank maybe next year. I was thinking of putting one holding tank for galley undercockpit floor behind bulkhead that seperates galley space from cockpit space. My plan is to install ball valved on outlet of tank, pump out line to deck fitting in head area hanging locker with Y vavle. Opposing leg of Y valve to furture head holding tank under v berth. Now, how do I connect the head sink? Is the distance between galley holding tank and deck fitting going to be to far for pump outs? I saw earlier post about rigid pipe for sections, would the run under the settes be OK for this? Can the head sink be gravity feed assuming the height difference s would allow for it? Any thoughts or links to diagrams would help. I welcome all suggestions.
Thanks Ted

Post by **dasein668** » Tue Jan 31, 2006 11:09 am

Do they forbid discharge of grey water where you sail? Yikes. There's new ndz regulations being prepared for Casco Bay, but it doesn't apply to grey water for recreational vessels.

There should be no problems with pumpouts sucking that distance (sink to deck) in a 26 foot boat. Rigid pipe should be fine under the settees. I'm not sure what you mean about gravity feed of the head sink? Are you trying to run that to the same holding tank as the main sink?

TBeyer · Post by **TBeyer** » Tue Jan 31, 2006 12:06 pm

We will be sailing on Lake Champlian and it is a no discharge area. For the head sink I was thinking of running it to the galley holding tank, then when a head holding tank is installed I would possibly switch it.

Post by **Tim** » Tue Jan 31, 2006 1:12 pm

You don't need much of a downslope in your line to make gravity feed work. In your house on shore, you only need a minimum of 1/4" per foot of run on waste lines, which isn't much at all. If the inlet to your holding tank is a couple inches or more below the sink drain over that length of a run, you're probably OK--especially since it's just water we're talking about here, which will flow down just about anything as long as it's not uphill.

If you use hose, be sure to avoid low or high spots and keep the run as even as you can. The PVC pipe route would be good here; just be sure to use lengths of hose at both ends so that the system can flex as needed with the boat's movement.

Good luck. I understand why places like Champlain need to be NDZs, but it sure makes for some tough and complex installations on small boats.

jhenson · Post by **jhenson** » Tue Jan 31, 2006 1:27 pm

If the sinks share the same tank as the head temporarily, how do you keep the odors from venting through the sinks. Is the a "trap" like in conventional plumbing?

Joe