I might connect the kitchen sink drain to the vent as well to keep water in that trap. I think it might otherwise be drawn into the wash water tank. Our '65 Caravel has such a vent.
How many vents do you currently have in the coach? Mine has 3. Two in the rear for the shower and sink and one for the kitchen amidships. I like your plan for the new gray tank. I would connect the kitchen sink drain to the tank vent and eliminate the extra fitting on the gray tank under the floor. I would also add a vent to the common bath sink and shower drain with a stack coming up the curbside wall. This would eliminate possible gurgling in the bathroom fixtures when the kitchen sink is emptied. It would also provide a backup if one vent became plugged.
Just remember what free advice is worth, Tom.
__________________ Airstream Forums Member # 2806 WBCCI # 6411 Not All Who Wander Are Lost.
Keep in mind that in a house you can have a drain line up to six feet without a vent. I'd be concerned with your kitchen drain line. I'd look at adding a vent to the kitchen drain line. It should connect with a sanitary T so it will mix air before the six foot mark.
I like Tom's idea of adding a vent to the shower side, except I'd connect the vent to the bathroom sink line, since it is the longest?
What type of tanks are you using? How are you attaching the gray tank to the belly of the trailer? I'm getting ready to do the same. Both my tanks are mounting below the floor.
Nice drawing by the way, mine are totally illegible- like my handwriting.
I like the suggestions above, and one other suggestion I would make is that where your black and gray vent lines "y" together on the street side, make that union fairly high up on the wall, so that the gases as well as the drain water don't mix below sink level. It's probably not likely this will happen, but better safe than sorry.
By the way, I think it's fine to tie those two vent lines together, that is the original configuration on my trailer and many others.
Ryan--
My new gray tank is mounted under the floor and has a flange or lip that extends out at the top, and slides comfortably into the c-channel portion of one main frame rail, and the c-channel portion of one x-member. Then I have a removeable support that bolts in from below that supports the lip of the other long side of the tank, with a stop welded on at one end to box the tank in completely. I made it removeable in case I ever need to pull the gray tank to service it, or the floor above it. You can see pictures of this on my blog linked below if you're interested, sometime around mid-December is when I received the trailer back from my frame welder. Just to note, it DOES hang below the belly-pan by several inches. I decided I liked the bigger size I could achieve with this setup.
I'm watching your project with great interest, you guys are blazing fast, keep it up!
Currently or previously I should say, I only had one vent, it was attached directly to the very small black tank - and after taking off the interior panel I found that it had long since rotted away so the venting was taking place in the walls. There was no gray tank and those lines didn't have any venting.
So it sounds like my theory that having the tanks vented ("unclosed") would be sufficient to prevent the traps from "siphoning thru" is not valid. I just thought that the reason traps would otherwise run dry was because they're normally in a closed system. The real reason (probably obvious) I wanted to only vent the tanks is I'm lazy - I didn't want to take more interior panels off . . . just trying to keep the worms in the can so to speak.
I bought my gray tank from ppl (and it wasn't shown on their website). I'll attach the measurement diagram they gave me. It's going to be installed just like Marcus describes above, and Ryan, I'm going to guess your 59 frame is basically the same. The tank does hang lower than the belly pan but if you keep it close to the axle it shouldn't cause problems AND you can hardly see it (that's my opinion anyway). I'll attach a detail section thru the tank/frame.
I really appreciate the comments/help/advice.
Thanks, MarkR
I added a single holding tank to my last trailer (a '59 18 footer). It was mounted fully below the frame and was approx. 9" from the ground. I never had any problems with clearance. The black tank I am getting ready to mount (this weekend I hope) will be 5-6" below the frame, so 10-11' ground clearance.
My gray tank will mount in a similar way to Mark's gray tank. The image on the right is really helpful for me to see. My big concern is the C channel is made of steel that was 1/16" 50 years ago and is a bit thinner now. Will that bottom lip of the C hold half of a 30 gallon tank? That's 120 lb. +/- bumping down the road. What are you going to do on the thin side to keep the tank in there? I am struggling with trying desperately to not over engineer the mount. When I'm not sure if it's enough, I like to throw a bunch of heavy steel at it. Then I weld the s**t out of it. I'd like to get to the 'less is more' state before the tanks come in the mail.
I saw the photos of the tank supports on your blog. Nice work! Pictures really are worth a thousand words. I've had something similar in mind, only with more bolts. The black tank on it's way has no mounting flanges, so I'll have to supply something to cradle it from below.
You can check my thread Slow floor replacement pages 13-16, installed 2 grays and 1 black.
Will start posting to thread in March, this has been a very bad record breaking Michigan winter.
Hi Mark,
I was just about ready to start a new thread on venting questions when I ran accross yours. Actually I think your original thoughts are correct. Our trailer came w/ no tanks, but everything was vented via a single 1 1/2 inch pipe that terminated under a streamlined roof cap. I think I'm going to stick w/ this method, but add black & gray tnks, of course.
Your Dwg. shows a raised shower pan. I'm just wondering if that will cause any headroom issues. Ours had a mid bath with the shower outbd. There's just no way it would have been comfortable for me. So we're going to great effort to swap positions w/ the toilet. P-trap will probably hang below belly an inch or so w/ a protective cover.
Just some thoughts - good luck w/ your project.
__________________ John Whyte Odessa, WA (the geographic center of nowhere)
Old Nuke -- Good to hear from you! Sounds like everyone here is adding the same stuff.I like the bathroom setup in your trailer, having everything in the middle like that.