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Bathroom Dry Pipe

Passin__Through
Explorer
Explorer
First of all I want to thank everyone here for several years of entertainment, education, and ideas gained from reading this forum. Although I rarely post, I look forward to visiting the website several times a week.
Here is an addition that has made the draining and flushing of my 5th-wheelerโ€™s black-water tank quite a bit easier. I installed a dry pipe in the bathroom right next to the commode. It is used to fill the tank with additional water just prior to dumping, and to add 5 gallons or so to the emptied tank to prevent the dreaded โ€œpoo pyramidโ€ before the next dump (no pun intended). The pipe is โ€œdryโ€ since it is only charged with water when the black tank is emptied.
I used ยฝโ€ sch.40 PVC pipe to run a line from near the dump connection on the street side, across the underbelly, then up into the bathroom next to the commode where a ยฝโ€ FPT brass quarter-turn hose bibb controls water flow. The street-side end of the pipe has a ยพโ€ female hose fitting to which my utility hose is connected. In use, a short length of ยฝโ€ I.D. vinyl tubing is attached to the bibb and pointed straight down the toiletโ€™s open waste valve to add water to the black tank. The tubing must be hand-held during this operation to prevent overfilling of the tank. Mine also has enough curl to it to prevent it from staying in the toilet and thereby eliminating the possibility of a cross-connection with fresh and waste water. When finished the utility hose is stowed and water in the pipe is allowed to drain out for a few moments, the FHT connection is plugged, the bibb is capped (even though it is unnecessary), and the vinyl tubing is put into a large ziplock bag and stored behind the commode. The vinyl has never gotten dirty so I have no qualms about storing it this way.
One caution โ€“ after pressurizing the pipe, be very careful opening the quarter-turn valve to fill the black tank. The line will have air in it and can splash water in the commode which can then land in places where it doesnโ€™t belong. Guess how I found this out. In addition, since my utility hose is also used for the tank flusher, I put a hose-end ball valve with a quick-connect fitting between the utility hose and the dry pipe inlet. When a hose switch is needed, I just turn off the ball valve to keep the line full of water, then attach the hose to the tank flush inlet via a brass 90-degree ell which is also equipped with a quick-connect fitting. A reconnect to the dry pipe will let a small amount of air back into the line but I can usually hear it coming through the pipe and close the valve a bit to eliminate splashing.
Here are some pictures that should make things more understandable than my poor efforts at written explanation. I didn't like having to make multiple trips with a 5-gallon water bottle to put in the toilet prior to having to dump a short-filled tank, nor dragging a long hose inside to do the job. Perhaps someone else can benefit from this idea.

Hole in the floor for 1/2" PVC pipe.



Detail showing homemade drop-ear ell, bibb and cap holder






Sprayed with satin finish black paint for plastic. The white cap is screwed to a 3/4"MHT x 1/2"MPT connector and used to just keep crud out of the line when not in use.
2008 Chevrolet 2500HD Duramax 4x4 CCSB; Superglide 16k hitch w/3" lift kit; Titan 52-gallon replacement fuel tank :C
2007 HitchHiker II LS 26.5RLBG Mor/Ryde pinbox:B
19 REPLIES 19

Seon
Explorer II
Explorer II
I kind a like your modification. Thx.

Passin__Through
Explorer
Explorer
I guess I wasn't too clear as to the purpose of the pipe. It is for putting additional water into the black tank prior to dumping in order to get as much solid material out as possible, then adding about 5 gallons of water after dumping is complete. It is not for flushing the toilet.

K Charles wrote:
Every camper we ever had the water goes down when you flush the toilet. If you want more water you move the pedal, or lever, the other way.


My toilet operates like any other, but filling the tank via the pipe I installed is much faster. To use it, the water pump is turned off (saving onboard water), the toilet flush pedal is depressed and held down, the vinyl tubing is directed into the toilet drain opening, and the bibb turned on. I can sort of gauge the black tank level by the sound the water makes as the tank is filled. When I can see the water in the waste pipe, or it sounds like it is close, I shut off the bibb, go outside, open the tank drain valve, and turn on the black tank flush. The pipe makes a secondary fill and dump, if necessary, much faster as well.

Sorry for any confusion. I am happy to answer questions anyone may have.
2008 Chevrolet 2500HD Duramax 4x4 CCSB; Superglide 16k hitch w/3" lift kit; Titan 52-gallon replacement fuel tank :C
2007 HitchHiker II LS 26.5RLBG Mor/Ryde pinbox:B

K_Charles
Explorer
Explorer
Every camper we ever had the water goes down when you flush the toilet. If you want more water you move the pedal, or lever, the other way.

Old-Biscuit
Explorer III
Explorer III
I have a 'sprayer' on my toilet that I use to rinse bowel with and if I hold toilet flush pedal down water runs continuously
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

jdc1
Explorer II
Explorer II
A Rhino Blaster or Flush King work great too...