Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-20-2016, 05:48 PM   #1
Rivet Master
 
PA BAMBI II's Avatar
 
1964 17' Bambi II
1961 24' Tradewind
Strasburg , Pennsylvania
Join Date: Mar 2010
Posts: 911
Venting gray tanks and sink

I am getting ready to start planning out my gray holding tanks (will be custom aluminum tanks) and plumbing my one and only sink. Several questions I am struggling with and hope to gain some insight from our awesome membership:

1) Due to massive space constraints under the floor of the Bambi II (small cavities/angle iron cross member connectors running the center/length of the trailer), I plan to tie together 2-3 smaller tanks with rubber couplings. Does each tank need to be vented, or just the one nearest the exit drain towards the release valve?

2) Can the sink vent be "looped" down through the floor/bellypan? I do not have easy access to a roof vent stack nor a clean way to install one. If not a looped system, can it go through the side of the trailer? How high does it need to be? Above water line/nearly to the top of the sink or must it just higher than the trap (Hepvo in my instance)

3) Can sink vent line be smaller than 2" plumbing pipe? Could PEX be used? (easier to work with/smaller, etc.)

Thanks for any insight. I built the interior/cabinets to fit our needs and we are very happy with them, but I am afraid it has made planning the plumbing more difficult. Kind of like putting the cart before the horse, but we wanted to get it up and running and have been camping without plumbing as it is a non-necessity. Now it is time to get it figured out.

Thanks!! Ben
__________________
"The difference between vintage and retro is that vintage is honestly old and cool. Retro tries to be but isn't."
PA BAMBI II is offline   Reply With Quote
Old 10-20-2016, 07:12 PM   #2
Rivet Master
 
A W Warn's Avatar
 
2000 25' Safari
Davidson County , NC Highlands County, FL
Join Date: Aug 2006
Posts: 4,493
Quote:
Originally Posted by PA BAMBI II View Post
I am getting ready to start planning out my gray holding tanks (will be custom aluminum tanks) and plumbing my one and only sink. Several questions I am struggling with and hope to gain some insight from our awesome membership:

1) Due to massive space constraints under the floor of the Bambi II (small cavities/angle iron cross member connectors running the center/length of the trailer), I plan to tie together 2-3 smaller tanks with rubber couplings. Does each tank need to be vented, or just the one nearest the exit drain towards the release valve?

2) Can the sink vent be "looped" down through the floor/bellypan? I do not have easy access to a roof vent stack nor a clean way to install one. If not a looped system, can it go through the side of the trailer? How high does it need to be? Above water line/nearly to the top of the sink or must it just higher than the trap (Hepvo in my instance)

3) Can sink vent line be smaller than 2" plumbing pipe? Could PEX be used? (easier to work with/smaller, etc.)

Thanks for any insight. I built the interior/cabinets to fit our needs and we are very happy with them, but I am afraid it has made planning the plumbing more difficult. Kind of like putting the cart before the horse, but we wanted to get it up and running and have been camping without plumbing as it is a non-necessity. Now it is time to get it figured out.

Thanks!! Ben
First understand the purpose of vents. From the waste tanks a vent lets methane gas (sewer odor) vent out. This vent also admits air into the tank when the tank is dumped. The smaller the vent the slower the tank will drain. At a fixture (sink drain, shower drain) air has to be admitted so that a vacuum is not created. At a sink a vent is not needed, but a vent is an optional way to admit air.

If you use multiple tanks you will need some type of vent from the top of each tank to allow air to escape when liquid builds up to the top of the outlet pipe. If the air can't escape liquid cannot fill the tank. The tank vent stack should go upward through the roof so that methane gas (odor) can be dispersed into the atmosphere. If a vent exits the trailer low on a side odor will be noticeable.

A vent is not required at each fixture. (Google air admittance valve). An air admittance valve is the proper solution when a vent is not available. At a sink, an air admittance valve should be placed as high as possible beneath the counter top where the sink is mounted.

I suggest that a tank vent should not be smaller than 1 1/2" pipe (though theoretically any size could work). Vents for multiple tanks can be tied together so that only one vent penetrates the roof.
__________________
Alan
2014 Silverado LTZ 1500 Crew Cab 5.3L maximum trailering package
A W Warn is offline   Reply With Quote
Old 10-21-2016, 07:23 AM   #3
4 Rivet Member
 
2021 16' Bambi
2021 22' Bambi
Currently Looking...
North Port , Florida
Join Date: Mar 2007
Posts: 331
I would recommend a drain size of 1 1/2". I installed these vents at each sink. These are installed just after the traps to allow air in to aid in draining.

http://www.homedepot.com/p/Oatey-1-1...9012/100204205

Yes, you need to vent each tank. Ideally bigger is better but if you have 3 small tanks you might be able to get away with a 3/4" vent from each tank plumbed into a single larger vent.
cliffcharb is offline   Reply With Quote
Old 10-21-2016, 07:45 AM   #4
Rivet Master
 
garry's Avatar
 
1969 31' Sovereign
Broken Arrow , Oklahoma
Join Date: Jan 2003
Posts: 1,455
Images: 7
A W Warn is spot on.

I also used the under the sink vents (air admittance valve) however, they will not work on the holding tanks as they are a one way valve.
__________________
Garry
garry is offline   Reply With Quote
Old 10-21-2016, 02:54 PM   #5
Rivet Master
 
PA BAMBI II's Avatar
 
1964 17' Bambi II
1961 24' Tradewind
Strasburg , Pennsylvania
Join Date: Mar 2010
Posts: 911
Quote:
Originally Posted by A W Warn View Post
If you use multiple tanks you will need some type of vent from the top of each tank to allow air to escape when liquid builds up to the top of the outlet pipe. If the air can't escape liquid cannot fill the tank. The tank vent stack should go upward through the roof so that methane gas (odor) can be dispersed into the atmosphere. If a vent exits the trailer low on a side odor will be noticeable.

A vent is not required at each fixture. (Google air admittance valve). An air admittance valve is the proper solution when a vent is not available. At a sink, an air admittance valve should be placed as high as possible beneath the counter top where the sink is mounted.

I suggest that a tank vent should not be smaller than 1 1/2" pipe (though theoretically any size could work). Vents for multiple tanks can be tied together so that only one vent penetrates the roof.
I am learning here. Thanks for the insight. I am happy to hear that I can use the special air admittance valve for the sink. That will save me some headache. I would put that after the Hepvo valve? And I will run the Hepvo horizontally to keep the plumbing, and hence the air admittance valve, close to the underside of the counter top.

I was afraid each tank would need a vent. I really am struggling with where to place them as there is no clean, clear place. I am wondering if I run the gray tank vents up beside the fridge if I could vent the gray tanks through the already existent fridge vent chimney? Ie. run PVC up into the chimney and let it go up along with the fridge fumes.
__________________
"The difference between vintage and retro is that vintage is honestly old and cool. Retro tries to be but isn't."
PA BAMBI II 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Black and Gray water tanks NavyDavesCvl 1956 - 1965 Caravel 4 03-20-2010 09:21 AM
'59 Tradewind I need new black and gray tanks tomsdayoff 1959-69 Tradewind 28 05-06-2008 10:31 PM
Propane tanks venting! Resorts LP Gas, Piping, Tanks & Regulators 20 06-22-2007 06:36 AM
Anyone have any luck putting Gray and black tanks in a 63 tradewind??? durans54 Waste Systems, Tanks & Totes 1 12-05-2006 08:56 PM
One sink, two sinks, red sink, blue sink? Janet H General Interior Topics 7 07-26-2006 06:17 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 02:55 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.