Smaller Pumpout Hose Diameter ?

[akio.kanemoto]

Howdy,

I'm just trying to install a pumpout fitting for my holding tank and having great difficulties routing the 1.5" toilet hose.

I was thinking - can I use a 1" toilet hose instead and just step it up to 1.5" just before the deck fitting? The smaller 1" hose bends much much easier than the 1.5" and would make my life a lot easier.

I am not contending for the World's Fastest Pumpout title, so am aware that it will be slower - but am more concerned with whether the pumpout could collapse a smaller diameter hose as there won't be as much flow as with a 1.5" hose, hence more vacuum.

Thoughts? Has anybody done this?

Thanks muchly in advance!

[SailFastTri]

It will work until it doesn't. Any chunks big enough to flush should be small enough to suck out. As for collapse -- yes that's a problem if you get a blockage (and a blockage is more likely with a small hose) but assuming your tank vent is not clogged -- any collapse would be limited to the pumpout hose.

[akio.kanemoto]

Originally Posted by SailFastTri

It will work until it doesn't. Any chunks big enough to flush should be small enough to suck out. As for collapse -- yes that's a problem if you get a blockage (and a blockage is more likely with a small hose) but assuming your tank vent is not clogged -- any collapse would be limited to the pumpout hose.

Tanks for the reply. Will give it a go then.

[ggray]

Should work.

I even used 1 inch hose from the head to the holding tank on our last boat. I had the same "bending" restriction as you, and I wanted to reduce the amount of liquid volume in the hose since I was pumping straight up to the tank.

There was no further diameter reduction because no barb fitting was inserted into the 1 inch hose. I used 1 inch "liquid tight", I think it was called , PVC electrical conduit. I found the coupling used with this stuff was just a hair bigger than 1 1/2 inch . With PVC cement I glued one of these couplings (actually cut one in two because they were longer than needed) to each end of the hose, and then used short lengths of 1 1/2 hose to connect to the original fittings on the tank and head. Yes, that's 2 extra hose clamp connections, but I never had a problem. The 1 inch hose was not much smaller than the ID of the 1 1/2 hose barb, so I figured it should work, and it did.

You could do the same thing with regular head hose,I expect. (I think regular PVC couplings are a bit bigger OD, so maybe the conduit couplings would work) I used the conduit because it was grey in color, which looked good in the head ( the routing run was front and center),plus it was a lot less expensive. I enjoy finding non marine products that work well.

Never had any problem, odor or other, over the ensuing 4 years we owned the boat.