How to empty standpipe?

[Geoff K]

Sail L. Superior; no discharge. Toilet to holding tank is a solid 1 1/2"PVC run except for the first 8" out of the toilet and the last 4" at the tank. Tank under V-berth. The uphill run to the vented loop (toilet side) contains 50 oz. of fluid. When it's time for maintenance on the toilet and removing the sanitation hose how can I empty the "standpipe" without dumping 50 oz of water all over? Is there a bypass valve I can put in there for future use?

Thanks

Geoff

 

[Stu Jackson]

Just pump the head clean for a while so all you have in that piece is clean water. Valves would only complicate a rare but necessary maintenance chore.

 

[Geoff K]

That's what I was planning. I just hoped there might be an easier way. If so, I'd probablly empty the pipe each winter instead of putting all that pink stuff in there. The standing water is 50 oz and the PHII pumps 6 oz a time so 20 pumps, 2 1/2 times the volume present should leave clean or almost so water in the pipes. We do that each time we leave the boat. No problems with head odor.

 

[Geoff K]

Update draining head stand pipe.

At season's end I pumped 35 times, about 4 times the volume in the standpipe then disconnected the hose. The water was clear but there was some particulate matter; I'll guess 1 oz if measured by volume. It was black, looked like fiber, (perhaps well used lettuce?), had no odor, largest piece about 3/4". There was some lying in the toilet outlet also. I'm assuming the straight standpipe of about 20" height is enough that some particulate matter will not go up with a slow hand pump. It has not been a problem but I think it could cause obstruction or lodge in the outlet valve. I'll plan on emptying that stand pipe every 2 years; will work on a three way valve to make it easier.

Geoff

 

[Peggie Hall HeadMistress]

There'll be a lot less water left in the line if you pump the toilet in the dry mode. In fact, you can double the number of flushes your tank can hold if you learn how to use the dry mode to flush most of the time. You'll find discussions on how to use the dry mode to flush instead of using it only to move the last of the water out of the bowl.

Happy New Year, y'all!

 

[Geoff K]

I do use dry mode

but that won't push the water out of the standpipe. Perhaps "standpipe" isn't the right term. The PVC leaving the toilet (PHII) goes horizontal about 10" and vertical about 24". then it does a 120 and goes down into the holding tank about 5 feet away. Pumping air into the standpipe only lets bubbles go through. I planned that from your book's recommendation to have a loop high enough that fluid can't back flow to the toilet at the highest expected heeling angle. I used 1 1/2" pipe because I didn't know how well the manual pump would break up the solids. Could I have used 3/4"?

I calculated the total volume in the standpipe to be 50 oz. We use very little water for each flush, usually one pump (6 0z) if no solids, but at the end of the day we pump 100 oz through. Before taking the standpipe connection off the toilet I pumped 200 oz through. The water was clear. The particulate matter was old, black and dry looking, although it was in water. (The Raritan folks told me 6 oz per pump and I calculated from there.)

The toilet was removed for 2 reasons; so I could do the rebuild kit at home duriing winter and because I need space to so some woodwork in the head.

Geoff

 

[Ron20324]

... Pumping air into the standpipe only lets bubbles go through.

Okay, so then put the shop vac on blow and stick the nozzle into the bowl.