I am replacing the vent and hose on my boat and the old vent is just reinforce nylon. Given all of the choices available is this the correct hose for this application?
What hose to use for black tank vents.
- Thread starter Hayden Watson
- Start date
If you can use a sanitation hose it would be better. While not as prone to odor permeation as the rest of the system, vent hose can end up with some of the contents in the hose. If you can't find sanitation hose in the right size for your vent, then you'll have fewer options. @Peggie Hall HeadMistress would probably tell you to enlarge the vent and use sanitation hose.
I think the only sanitation hose available in smaller sizes is the white Trident 148 and similar from other manufacturers. Although this is not the best hose for waste, it works very well for vents. I used it on my last boat (cruising cat) after clear vinyl failed (the OEM hose failed, and my replacement started to stink soon too) and was quite pleased.
Yes, the nylon reinforced clear vinyl (what I think you were describing) will permeate within a few months. It also kinks too easily, resulting in a blocked vent.
Good luck!
Yes, the nylon reinforced clear vinyl (what I think you were describing) will permeate within a few months. It also kinks too easily, resulting in a blocked vent.
Good luck!
It would be too easy and too inexpensive, so obviously it won't work on a boat.
Sorry, you got me at a cynical moment.
You definitely want to use sanitation hose. If your vent line is the standard 5/8", flex PVC #148 is the only sanitation hose available in that size. It's not permeation resistant, but shouldn't start to stink for at least a couple of years and it's cheap to replace.
However, this would give you the perfect excuse to upgrade your vent to 1", which isn't that hard to do thanks to a li'l gizmo called the Uniseal UNISEAL That'll not only provide the air exchange necessary to keep the tank aerobic --which is the key to odor prevention--but you'll also have to enlarge the vent thru-hull (IF you've already relocated it from the rail stanchion to a thru-hull...if not, it's something you really NEED to do!), requiring an open bulkhead or mushroom thru-hull instead of a "vent" thru-hull, which is only available in 5/8", allowing you to use top quality sanitation hose that's 100% odor permeation resistant. And that would be Raritan SaniFlex hose RaritanSaniFlex hose.
More details if you want them.
--Peggie
However, this would give you the perfect excuse to upgrade your vent to 1", which isn't that hard to do thanks to a li'l gizmo called the Uniseal UNISEAL That'll not only provide the air exchange necessary to keep the tank aerobic --which is the key to odor prevention--but you'll also have to enlarge the vent thru-hull (IF you've already relocated it from the rail stanchion to a thru-hull...if not, it's something you really NEED to do!), requiring an open bulkhead or mushroom thru-hull instead of a "vent" thru-hull, which is only available in 5/8", allowing you to use top quality sanitation hose that's 100% odor permeation resistant. And that would be Raritan SaniFlex hose RaritanSaniFlex hose.
More details if you want them.
--Peggie
The Trident 148 is pretty stiff and hard to route sometimes, but it makes a good vent and is available in all the common sizes. It's what I used on my last two boats.
Thanks s. @Peggie Hall HeadMistress. I needed to replace my black tank head vent stanchion due to cracking at the base and purchased a solid base instead. My plan had been to install this Flush Mount vent. There is not a lot of depth available for the hose in the cabinet where it gets mounted. Any suggestions for 1" vents that would fit in the available space? I need a right-angle thru-hull.
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@Hayden Watson I don't think you want a right angle thru hull, which will restrict air flow.
Check out this link. Replacing Stanchion Vent Very good photos of what @Smunkey did on his boat in post #15.
I installed mine the same way and put the thru hull in the same place. I used the Trident PVC 148 white hose. Yes the hose is stiff but that forced a nice gradual bend which I'm sure helps with the air flow. I used a standard 1" mushroom head thru hull with hose barb.
Just one word of caution. There is a gap between the liner and hull. I filled the gap with thickened epoxy so I didn't deform the hull while tightening the thru hull.
Check out this link. Replacing Stanchion Vent Very good photos of what @Smunkey did on his boat in post #15.
I installed mine the same way and put the thru hull in the same place. I used the Trident PVC 148 white hose. Yes the hose is stiff but that forced a nice gradual bend which I'm sure helps with the air flow. I used a standard 1" mushroom head thru hull with hose barb.
Just one word of caution. There is a gap between the liner and hull. I filled the gap with thickened epoxy so I didn't deform the hull while tightening the thru hull.
All "vent" thru-hulls are designed to keep sea water out of the fuel and water supply and Catalina's idea to run vent lines into a rail stanchion is a good idea for the fuel and water tank vents...but NOT for waste tanks 'cuz it doesn't allow much if any air exchange and neither do the "vent" thru-hulls. So even if you keep the 5/8" vent, you'll want to use a bulkhead or "mushroom" thru-hull, which not only allows the needed air exchange, but allows you to put a hose nozzle against it and backflush the vent line every time you wash the boat, which will prevent ever having a blocked vent. In addition to washing out any waste that spills into the vent, any insects that try to set up housekeeping in the vent line will just have a water slide ride into the tank. Use a thru-hull that has a straight barb, not a 90.
+1 for Ward's suggestion to check out the "Replacing Stanchion Vent" thread.
--Peggie
+1 for Ward's suggestion to check out the "Replacing Stanchion Vent" thread.
--Peggie
I am trying to figure out why a 90º bulkhead fitting would be a problem. Air can bend the angle with little change in pressure and it would give me the room to install the 1" vent. I need it to go into the foreward end of the port bin and that can only be done with the 90. In plumbing, the vent lines use tight 90º elbows whereas the lines that carry water need to have sweep 90's.
A holding tank vent isn't a plumbing vent..it doesn't just provide an escape for air, it has to provide a means of exchanging ambient air with gasses inside the tank which are heavier than ambient air. Therefore, to keep the tank aerobic, the vent line needs to be as short, straight and horizontal as possible...which on a sailboat is difficult enough without introducing any 90s into it.
So I'm not sure that your choice of thru-hull location will work, with or without a 90 in the vent line. If you'd like to discuss how to do it right in more detail than is practical here, send me a PM. We're in the midst of a major snowstorm that has me housebound for at least another 2 days, so I'll have plenty of time for you.
--Peggie
So I'm not sure that your choice of thru-hull location will work, with or without a 90 in the vent line. If you'd like to discuss how to do it right in more detail than is practical here, send me a PM. We're in the midst of a major snowstorm that has me housebound for at least another 2 days, so I'll have plenty of time for you.
--Peggie