Second Gate Valve for Grey Tank

[Apalinto]

Greetings to the group. We have a 2019 Cougar 315RLS. I spent a lot of time underneath the trailer last week, mostly inspecting my gas lines that are rusting really bad and prematurely in my opinion.

Anyway I noticed a gate valve on the grey tank drain line just before it joins in with the main sewer line drain point. In the convenience center, there is already a valve handle for the grey tank, so is this one underneath the trailer a "secondary" gate valve for the grey line? I was thinking that you would want this closed when you let go the black tank? Anyway, you learn something new every day. Anyone know the purpose of this valve?

Regarding the gas lines, has anyone proactively replaced those cheap steel lines with stainless or copper to avoid a leak down the road due to corrosion? We live in a relatively dry climate and have only taken regional trips in California during dry weather.

Thanks for looking in.

[FlyingAroundRV]

My guess would be that this valve might be an "anti-backflow" preventer. If the pipe upstream of this valve is level or nearly level, this might be to stop the black tank stuff flowing up that pipe.

[chuckster57]

Originally Posted by Apalinto

Greetings to the group. We have a 2019 Cougar 315RLS. I spent a lot of time underneath the trailer last week, mostly inspecting my gas lines that are rusting really bad and prematurely in my opinion.



Anyway I noticed a gate valve on the grey tank drain line just before it joins in with the main sewer line drain point. In the convenience center, there is already a valve handle for the grey tank, so is this one underneath the trailer a "secondary" gate valve for the grey line? I was thinking that you would want this closed when you let go the black tank? Anyway, you learn something new every day. Anyone know the purpose of this valve?



Regarding the gas lines, has anyone proactively replaced those cheap steel lines with stainless or copper to avoid a leak down the road due to corrosion? We live in a relatively dry climate and have only taken regional trips in California during dry weather.



Thanks for looking in.

How many gray tanks do you have? How many pull handles in the convenience center?

[Apalinto]

Thanks Scott, I believe you are right. I have drained my grey tank a few times already and never used it! Never really knew it was there! I'll just keep it closed when dealing with the black tank going forward.

[ROBNPEN]

If your trailer is anything like my 310RLS, you have two grey tanks. One connected to your shower with the valve handle in the convenience center; and the other connected to the kitchen sink with the valve handle under the RV to the right of the convenience center.

[5J's]

I'm thinking a secondary gray tank as well.

[Apalinto]

Right, I know what you mean, but no, my unit has only one gray water tank, it is 76 gallons. I will speak with my Cougar specialist at the dealer. I am thinking it is more like what Scott is saying above, that is that it's more likely a way to prevent cross contamination. I'll certainly update you all.

[ROBNPEN]

On the Keystone site, mine is posted to have one 76 gallon tank, but its actually two 38 gallon tanks. I found it out the hard way when my sink wouldn't drain, though I emptied the grey tank in the convenience center.

[travelin texans]

I'd bet you have 2-38 gallon tanks!
Regardless if one or 2 tanks they should all remain closed til time to drain, especially the black. NEVER leave the black valve open regardless if connected to sewer.
When we had full hookups I would leave the bath grey open til a few days before draining the black, it had the shower & wash machine going into it filling quickly & would always fill backing up into the shower usually when the DW was in it, then the hammer dropped.

[Brentw]

And on your steel propane line, I would be very surprised if it was more than surface rust, it would take a long time for external corrosion to weaken that pipe. Tap it with a hammer, don't beat it up though, if it sounds good, let it be. I would be hesitant to install copper under a travel trailer.

[Apalinto]

OK, I just heard back from my Cougar Specialist and he confirmed exactly what ROBNPEN, 5J's and traveling texans posted, the Cougar 315RLS has two 38 gallon tanks! I feel like a goof! Now I know what to do. Thanks for the tips! And thank you Brentw, the gas lines are solid to the tap, just a lot of surface rust. Trailer is quite new. Going to lay low on that one for a while. First dry camping trip coming up in August, Motorsports Reunion up in Monterey, getting the generators out!

[Brentw]

Right on, wear that thing out.

[travelin texans]

If the RV was delivered from the factory in winter all the salty roads from Indiana helped accelerate the rust. If it bothers you badly use a wire brush to clean it up a bit & paint it with some Rust-Oleum or POR50.

[Apalinto]

Right, already wire brushed. It is worse on the front gas line that runs across vs. the line that runs down the driver's side. Painting with rustoleum is a good idea. Thanks.

[Landkduncan]

Our 2019 Cougar 315RLS has two gray tanks. One for the bathroom sink and shower and the other is for the sink in the island. One gray tank valve is in the convenience center with the black tank valve. The other is outside to the right of the convenience center under the edge of the trailer.

[Apalinto]

Thanks landkduncan. I have one grey tank gate valve in the convenience center and a second gate valve under the trailer just before the main grey line joins with the black tank line. I have (2) 38 gallon grey tanks.

[bobbecky]

Two grey, one bath and one galley. And for the gas line, get a can of black rustoleum and spray it and you will be good.

[Preyou]

I have a 315RLS also. See my post "315RLS issues" It is about the valve you are concerned about. The valve is for the #2 Grey water tank. You should have an indication on the In Command screen for the #2 tank. It handles the kitchen drains. You basically have to crawl under the unit to open/close the valve. Keystone says they designed it like that and have no plans to change it. Maybe if enough of us complain, something will happen

[larryflew]

LOT of years in HVAC and even in worst salt conditions never saw a steel gas line rust all the way through in less than 40 years. Some from the 30's where in bad shape and needed replacing but even those where not rusted enough to leak. Go with the paint and sleep well.

[Jbrobson1958]

Almost bought one of those, but was under the impression from dealer, cougar, keystone it was one 76 gallon tank. Glad to have avoided that. Makes no sense to me that the kitchen and shower need equal size tanks.