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syke 09-09-2011 02:59 PM

Black tank dump valve
What is everyone using for a black tank dump valve?

I've seen quite a few of the RV (poor quality) blade style valves just fall apart and I don't think I want to go down that road. There has got to be something better than that out there.
The 3" pvc ball valve is way overkill. A copper gate valve is nice but again way overkill.

Any ideas?

bus-bro 09-09-2011 04:59 PM

Re: Black tank dump valve
I saw some beefier blade type valves in the Farm-Tek catalog. Don't have the catalog with me, so I can't say they had 3" valves. But, IIRC, they did and they were forty some bucks.

Stuff 09-09-2011 05:25 PM

Re: Black tank dump valve
go with the plastic if you must but being a ball valve it will trap water inside the center and could bust when frozen. that is why they go with gate valves.

lornaschinske 09-10-2011 12:43 AM

Re: Black tank dump valve
Don't kid yourself. An RV blade valve will freeze and come apart from freezing. Water will freeze and push the gasket out of wack causing the blade to leak (then crack from freezing water). We replaced one valve and rebuilt the other due to freezing temps in S GA. Redoing a black waste valve is such fun. Redoing the grey in only slightly less so. We will use the pvc ball valves and they will be inside an insulated bay that can be heated (all you need is a 60Watt incandescent light bulb). Lots of ways to heat the water bay. For all the other winters, we wrapped pipe heat cable (Frost King or Easy Heat brand) around the valves and built a temporary box out of pink or blue insulation sheathing. We put a small space heater plugged into a thermostat electric plug (Easy heat brand) and turned the heater on to low. When temps drop down to almost freezing, the heater will receive power and stay on until the exterior temps warm back above freezing. You can set an incandescent light bulb up on the same setup.
EasyHeat Pipe Heat Cable
EasyHeat Plug In Thermostat

Since we are heading into winter.....
The pipe heat cable can also be used on a water hose (laid flat -- do not spiral it) and covered with pipe insulation (use one size larger than your hose) and sealed shut with tape (the self sealing will not last). I like the neoprene but that's costly. The cheaper foam will work if you can cover it up well using water-resistant/weather resistant tape. These winterized water hoses take up a lot of room when stored. So you may not want to do up a 25 ft hose if you do this. You need to allow enough "extra" heat cable on both ends to wrap the hose bibb (usually on the bibb itself not the pipe stand) and the city water hookup on the RV/Bus. These are the two vulnerable spots in the water system. I have a couple extra inches to loosly wrap around the campground hose bibb and I place a "bag" made of Reflectix over the heat taped hose bibb and secure closed with a bungie cord. Most campgrounds that are open in the winter have their pipe stands heat taped and insulated. But the bibbs usually aren't protected. On the city water inlet on the side of the Class C, I put one of those foam hose bibb protectors like what you would use on a house hose bibb. I wrap a section of the heat tape around the metal connections and cover it all up with the foam cup (you have to notch out to allow the insulated hose to fit inside the cup). I leave my hose set up like this all year unless I am stripping off the insulation to replace. The foam cup and Reflectix Baggie get put away so that I can loose them and have to redo again every winter. :? Best thing to do is to put your water/sewer connections inside a bay to where you can heat them when temps drop to freezing. Means one less thing to worry about, even if you never plan on being in freezing temps.

syke 09-12-2011 12:14 PM

Re: Black tank dump valve
Thanks for the info.
What do you think about something like this:

I wanted to stay with the ball valves given that the rest of my water system uses them, but at 3 inches and being schedule 40, it is damn near impossible to turn. I would need a ball valve that is not designed to hold back a huge amount of pressure. :)

Let the search continue....

bus-bro 09-12-2011 01:25 PM

Re: Black tank dump valve
I, of course, think they look great, and wish I knew about those when I did my tanks.

One advantage of the RV valve, though, is you can change-out the valve guts in place, easily, with spare parts that are everywhere.

Stuff 09-12-2011 02:26 PM

Re: Black tank dump valve
one thing about heat tapes, stay away from the button style like in lorna's pic. the button is the ONLY source of on/off. so if the button warms up, it shuts off, tape does nothing. best is "self regulating" type.

lornaschinske 09-12-2011 04:55 PM

Re: Black tank dump valve

Originally Posted by Stuff
one thing about heat tapes, stay away from the button style like in lorna's pic. the button is the ONLY source of on/off. so if the button warms up, it shuts off, tape does nothing. best is "self regulating" type.

I've been using that exact style (in three sizes) since 2006. Granted I don't stay in New York, but the winters got well below freezing in Socorro, NM, Franklin, NC and Elizabethton, TN. As far as that goes, we got freezing temps in Cordele, GA and Corpus Christi, TX. They worked just fine. This particular style is the most commonly used heat cable among RVers who build their own insulated winter hoses. One of the cables I simply wrap around the idiot Blade valves to keep them thawed... it works and works well. There is no reason why the heat tape should be on if the ambient temps are warm enough.

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