Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-26-2013, 06:06 PM   #1
2 Rivet Member
 
1968 20' Globetrotter
1993 32' Excella
Jax , Florida
Join Date: Apr 2013
Posts: 72
Vents- what is really needed?

Okay I'm about to finalize all of my new drain plumbing in my '68 AS Globe trotter project.
I have done away with two of the three roof vents due to complete re-plumbing. I have the newer one way vents at each drain location(sinks, shower), I am definitely going to vent the new separate black tank through the roof, my question is:

Do I need to tie the grey water tank into that roof vent? It would be easy enough, but I'm a little afraid of smells etc(even though I have traps)
I think the one way vents will be fine, but my only reason for asking is my thoughts about when I drain the grey tank- it might "chug-a-lug" annoyingly without a bigger roof vent?
__________________

__________________
luvoldstuff is offline   Reply With Quote
Old 07-27-2013, 06:44 AM   #2
2 Rivet Member
 
1968 20' Globetrotter
1993 32' Excella
Jax , Florida
Join Date: Apr 2013
Posts: 72
My new walls are only half inch thick, so I am only using the original oval vent pipe that is in the wall by the kitchen sink.
__________________

__________________
luvoldstuff is offline   Reply With Quote
Old 07-27-2013, 06:53 AM   #3
Rivet Master
 
65CV's Avatar
 
1959 26' Overlander
Western , Massachusetts
Join Date: Sep 2005
Posts: 1,449
Images: 6
You absolutely need to vent the grey tank or it will empty VERY slowly as it "chug-a-lugs".

IMHO, if you have adequate traps, you can probably merge the vents, although your vent diameter does sound small.
__________________
65CV is offline   Reply With Quote
Old 07-27-2013, 07:45 AM   #4
2 Rivet Member
 
1968 20' Globetrotter
1993 32' Excella
Jax , Florida
Join Date: Apr 2013
Posts: 72
The grey tank, at this point,(if I don't tie into roof vent) is vented by the 3 undercounter "one way" vents. I would think that would be plenty(for dumping)?.....but
I will probably go ahead and tie the grey vent to the stack since I'm just not sure, if I get smells I could re-route(cap tie in) it later and see how it drains??
I shouldn't get any smells with traps though- home sinks are tied into the sewer-although no holding tank?
__________________
luvoldstuff is offline   Reply With Quote
Old 07-27-2013, 09:10 AM   #5
2 Rivet Member
 
awryawry's Avatar
 
2000 27' Safari
Durango , Colorado
Join Date: Jul 2013
Posts: 78
Images: 1
I believe that the air-admittance valves will adequately vent the GW tank for gravity drainage. As noted on another thread, I believe that the OEM valves are inadequate, and should be replaced with modern, code-approved AAV's. Talk to a plumber or a plumbing-parts supplier.

wry
__________________
.... pursue ease and grace ....
awryawry is offline   Reply With Quote
Old 07-27-2013, 01:47 PM   #6
Rivet Master
 
1988 32' Excella
Robbinsville , New Jersey
Join Date: May 2012
Posts: 1,010
I'm not a plumber but wouldn't only having "one way" vents cause a problem?

I mean air has to leave the tank to let water in and air has to enter the tank to let water out.
__________________
Wazbro is offline   Reply With Quote
Old 07-27-2013, 07:00 PM   #7
2 Rivet Member
 
1968 20' Globetrotter
1993 32' Excella
Jax , Florida
Join Date: Apr 2013
Posts: 72
That really is an interesting thought!!!?........I never thought of it that way. You may be right! I ended up venting both tanks through that one roof vent (today) anyway, just hope no sewer smells somehow make there way through, but maybe I'm over-thinking it anyway, I'll post some pics, 'cause threads without pics kinda suck!
__________________
luvoldstuff is offline   Reply With Quote
Old 07-28-2013, 09:49 AM   #8
Rivet Master
 
InsideOut's Avatar

 
1956 22' Safari
Vintage Kin Owner
Conifer/Evergreen , Colorado
Join Date: Feb 2002
Posts: 11,793
Images: 108
Quote:
Originally Posted by Wazbro View Post
I'm not a plumber but wouldn't only having "one way" vents cause a problem?

I mean air has to leave the tank to let water in and air has to enter the tank to let water out.
I'm not a plumber either - but that's how I thought it worked too...

Shari
__________________
Vintage Airstream Club - Past President 2007/2008
WBCCI #1824 - DenCO Unit Past President (2005)
AIR #30 - Join Date: 2-25-2002

RMVAC | WBCCI DenCO Unit | Sisters on the Fly | Tin Can Tourists
BIRDY - our 1956 Safari | 1964 Serro Scotty
InsideOut is offline   Reply With Quote
Old 07-28-2013, 10:07 AM   #9
2 Rivet Member
 
awryawry's Avatar
 
2000 27' Safari
Durango , Colorado
Join Date: Jul 2013
Posts: 78
Images: 1
What happens is that the drainage water introduced into a waste tank very gradually compresses the air within the vessel, and that pressure builds and builds over time until it explodes with a biblical fury -- and that's why there are so few AirStreams around today ....

Beware the toilet cough!

wryawry
__________________
.... pursue ease and grace ....
awryawry is offline   Reply With Quote
Old 07-29-2013, 11:10 AM   #10
Rivet Master
 
65CV's Avatar
 
1959 26' Overlander
Western , Massachusetts
Join Date: Sep 2005
Posts: 1,449
Images: 6
Try picturing it this way:

- you pour a gallon of water into one of your sinks
- in order to get that gallon of water to drain, 1 gallon of air has to leave the gray tank
- the other two sinks have traps that prevent stinky air from getting into your trailer. They won't let that gallon of air out of the tank.
- the sink with the gallon of water in it has a air admittance valve -- it will allow air to go into the tank, not out.

If you don't let that gallon of air out of the tank to the outside world, how would you expect to get that gallon of water into the tank? (If it does drain, that stinky air is getting by a defective trap into your trailer.)

You need a vent.

Hope that helps.
__________________
65CV is offline   Reply With Quote
Old 07-30-2013, 06:12 AM   #11
2 Rivet Member
 
1968 20' Globetrotter
1993 32' Excella
Jax , Florida
Join Date: Apr 2013
Posts: 72
Thanks, that makes sense. Good way of explaining it. I went ahead and vented the grey tank into the roof vent and everything seems to be draining fine.
__________________

__________________
luvoldstuff is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:25 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.