Shore Pumpout minimum hose size//and vent

[KenCamp]

I have a new fresh-water intake electric macerator toilet. I have chosen, rightly, or wrongly, to use one-inch Trident-premium rubber hose for the outlet to the toilet to the holding tank and to the overboard discharge. If possible, I'd like to use the same type of one-inch rubber hose to the deck discharge coupling (which I understand normally takes a 1 1/2 inch hose).

Is it possible to run a one-inch hose to the deck fitting with an adapter so that the one-inch hose can be connected directly to the deck fitting? Would this cause any problems?

Also, what size should the holding tank deck vent be?

The holding tank is a rondo plastic tank.

Ken

 

[Ron20324]

Seems most people want to reinvent the wheel, but, well, since you mentioned "wrongly", let's go with that. By the time you get adaptors for all the smaller than "standard" hoses you expect to use, (and still need 1.5 hose anyway) you'll be upping the cost. Also, more connections make for more places for leaks to happen. Not sure why you want 1-inch except for the flexibility, but that's your choice.

As far as 1" to the deck fittings/hoses, "Is it possible to run a one-inch hose to the deck fitting?", sure ANYTHING is POSSIBLE, but that does not make if the thing to do. Be careful that the pumpout hoses are a bit more than twice the area of the 1-inch hose. That MAY cause a problem with the pumpout pump, not to mention maybe collapsing your hoses with the suction.

The tank vent should be anything bigger than whatever is probably there. One inch, for sure, but i upped mine to 1.5 since i had to buy the vent hose anyway, and the new thru-hull was not that much more.

 

[centerline]

the difference in volume carrying capacity of liquid, between a 1 inch and 1.5 inch pipe is almost 5 times... when it is carrying effluent of a semi solid product such as human waste/TP, the chance of it becoming plugged with solids are almost 3 times greater on top of that... nearly 15 times greater chance of it becoming impacted....

you can see this chart for flow rates of the different sized piping.

I am only offering the information, and can only say that the 1.5" hose used in the system is standard for a very good reason. and even though you are attempting to use a macerator to compensate for the lack of size in the discharge lines, the effluent is still prone to plugging in a 1" line...
the line itself is overly small for the application, but where it slips over the barb fittings, the inside of the fittings are usually only 3/4 of an inch, sometimes only 5/8".... problem spots.
the paper and a lot of the solids will float at times, and when you pump out, the liquids will be pumped out first, and when the level gets down, it gets to the thicker product... then the chance of problems rise drastically.

and trying to run a passive snake down the tube to try and unclog it.... it aint gonna happen in a 1" hose, so you are reduced to disassembling it to find the clog with a LOT of raw sewage that has nowhere to go....


as for the VENT.... 5/8" or 3/4" would be standard... and two vents would even be better.

best of luck

 

[KenCamp]

Thank you everyone. I'll reconsider on your advice, go with a 1 1/2 inch hose to the deck fitting. Thank you.

Ken