Successfully eliminated “P” trap under sink with Hepvo valve

Comments

• YanniLazarus Member Posts: 366

  September 2020

  this is my installation in aT@B320S 2020 model.   With the drain on the left of the sink it was hard to get a straight shot to the corner waste line to work.   Using a 1 1/2" threaded plastic nipple (black plastic) just below the sink drain kept everything as high as I could get it,  and the drain line is as short as possible.   Very happy! 
  

  Yanni Lazarus 2020 T@B320S, 2018 RAV4 Adventure, Central CT
  

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• Dalehelman Member Posts: 2,414

  September 2020

  You should have been able to connect the Hepvo directly to the bottom of the sink. There by gaining another 3 or 4 inches. 

  
  

  1. Hash  T@B Fun

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• YanniLazarus Member Posts: 366

  September 2020

  I couldn't get that to work- my sink drain is closer to the corner than yours,  so your horizontal run came low enough on the stack to get the fittings to work.   I just dropped mine the 1 1/2 inches for the nipple.  My drain location made it harder. 

  Yanni Lazarus 2020 T@B320S, 2018 RAV4 Adventure, Central CT
  

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• YanniLazarus Member Posts: 366

  September 2020

  Hmmm. Plus the fittings. So you are right. Probably around 3 inches lost- but since my drain is closer to the corner,  overall not so bad. 

  Yanni Lazarus 2020 T@B320S, 2018 RAV4 Adventure, Central CT
  

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• Dudlee Member Posts: 24

  September 2020

  I was wondering if pulling the sink up and rotating it 180 to get the drain away from the corner would be worth it.  The install photo of jkjenn Looks like that’s what the crew did?

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• Dalehelman Member Posts: 2,414

  September 2020

  Still looks good.

  1. Hash  T@B Fun

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• YanniLazarus Member Posts: 366

  September 2020

  I think if I were smarter and used other fittings it might have worked a bit better.   The slip fittings I used required some minimum tubing lengths.  I do think keeping the horizontal run as short as possible is best (and laziness) kept me from exploring rotating the sink. 

  Yanni Lazarus 2020 T@B320S, 2018 RAV4 Adventure, Central CT
  

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• ReenieG Member Posts: 283

  September 2020

  @ReenieG, I agree with regard to the original pic you posted--there is no vent on the sink drain, and that suggests the Hepco valve itself does not require a vent to function properly.
  
  Regardless, the grey tank itself must still be vented to prevent pressure from impeding drainage. I assume in your pic (which is not a T@B) the grey tank is probably vented in another location that is more convenient for the layout of that particular camper.
  
  If you go look at your 320 I'll bet a nickel it looks like the pictures Dalehelman posted with the vent in place.

  
  @ScottG Yes, I have no doubt the pic I took which Dalehelman circled is MY undersink piping. I guess my "confusion" is that in that pic I posted of my T@B where Dalehelman circled, I don't see a vent. I will have to actually LOOK and see for myself I suppose, lol. 
  
  

  2018 T@B 320S / 2024 Chevy Blazer RS AWD / Phoenix, AZ
  

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• VictoriaP Member Posts: 1,496

  September 2020

  ReenieG said:

  @ReenieG, I agree with regard to the original pic you posted--there is no vent on the sink drain, and that suggests the Hepco valve itself does not require a vent to function properly.
  
  Regardless, the grey tank itself must still be vented to prevent pressure from impeding drainage. I assume in your pic (which is not a T@B) the grey tank is probably vented in another location that is more convenient for the layout of that particular camper.
  
  If you go look at your 320 I'll bet a nickel it looks like the pictures Dalehelman posted with the vent in place.

  
  @ScottG Yes, I have no doubt the pic I took which Dalehelman circled is MY undersink piping. I guess my "confusion" is that in that pic I posted of my T@B where Dalehelman circled, I don't see a vent. I will have to actually LOOK and see for myself I suppose, lol. 
  
  

  @reenieG The circled area in that pic IS part of the vent stack, the 90° elbow above where the sink drain attaches to the vertical pipe leads to the horizontal pipe behind the toilet and exits (vents) out the driver’s side of the trailer. 
  
  

  2019 320s BD Lite, white with blue (“Haven”)
  2015 Subaru Outback 3.6r (unsafe 200lb tongue weight limit until 2020 models)
  2020 Subaru Outback XT
  Pacific NW

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• Kr@cken Member Posts: 146

  September 2020

  Another newbie question. What would I want to replace my P trap. Is this something that is recommended?

  Kr@cken
  2020 T@B 320 Boondock
  Factory Victron Solar, Norcold 3 way Fridge
  Clueless about everything electronic
  2020 Subaru Ascent 
  Bainbridge Island, Wa

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• Sharon_is_SAM Member Posts: 10,061

  September 2020

  It is done to free up space under the sink as the “p” hangs down lower and the Hepvo can be mounted parallel to the floor.  What kind of trap do you have under your sink in the 2020 Boondock?

  Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  

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• Travelin3D Member Posts: 174

  September 2020

  I just did this mod in June on my 2020 320 BDL. Here’s a before and after.
  
  

  Richie, Mickie and Satchmo
  2020 320S Boondock Lite (silver w/blue)
  2019 Subaru Ascent Premium

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• GatorEgg Member Posts: 482

  September 2020

  Nice.  But the ptrap keeps my Keurig kcup secure in there. 😬

  2022 TAB 400 Boondock, 2019 Toyota Tacoma Sport 4x4
  2018 TAB 320 Boondock (previous)
  Odessa, Fl.  
  
  

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• TXMacDad Member Posts: 2

  May 2021

  Our sink mod in 2014 T@B 
  
  

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• rcarlson1957 Member Posts: 264

  June 2021

  Finished mine yesterday. 

  2018 TAB 320S Silver/Black w/100ah Lithium/Bluetti Solar Battery & Portable Solar Panels
  2020 Honda Ridgeline RTL (AWD) Lunar Silver Metallic w/Bluetti Charger 1
  North Texas - Retired Air Force/Corporate Trainer
  Trips - 48  Mileage - 63,452
  "Our favorite trip will always be our next one"

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• Denny16 Member Posts: 5,431

  June 2021

  Looking good...  
  cheers
  

  2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.

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• ReenieG Member Posts: 283

  September 2021 edited September 2021

  I finally did mine. There was alot of buildup in the p-trap, probably from water evaporation when storing. Just hoping this all doesn't leak! I'm always leery of plumbing fittings when I glue them together, although it's more me than them.
  

  I'm planning on replacing the faucet with a mod I saw from Facebook (link to faucet) and possibly replacing the sink, (link to sink) since it would prob still be doable. (sink is reportedly 1" deeper) Since I used a flex drain fitting I may still be able to mod the sink, although I'm still considering the microwave install under the sink which I think might be sink OR microwave, not both. We'll see after the faucet install.

  
  

  

  2018 T@B 320S / 2024 Chevy Blazer RS AWD / Phoenix, AZ
  

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• ReenieG Member Posts: 283

  September 2021 edited September 2021

  @Dalehelman @LittleBoyBlue I like your mod appearances better than mine. Not sure why mine looks slanted in the final pic. Hmmm... It looks like your mod might have been easier to do with those white connections. If mine leaks, I'm copying yours, lol.
  

  2018 T@B 320S / 2024 Chevy Blazer RS AWD / Phoenix, AZ
  

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• GPS_Jon Member Posts: 3

  April 3 edited April 7

  I did this one.   My first post   2019 320 SBD. The sink didn’t let me route directly to the drain. 

  
  

  Is the black drain pipe securely mounted to the grey tank?  Mine isn’t and can be lifted up and down inside lower cabinet. 
  

  

  

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• ScottG Administrator Posts: 5,654

  April 3

  Good question. My guess--and that's all it is--is that the black drain enters the grey tank through a rubber flange of some sort. This would allow a bit of movement as the trailer gets banged six ways from Sunday rolling down road.

  2015 T@B Max S (320)
  2015 Nissan Frontier SV V6 4x4

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• AnOldUR Member Posts: 1,719

  April 4 edited April 4

  @GPS_Jon
  

  Another non-plumber person who used the rubber couplers rather than PVC glue.
  I kept the p-trap. Swung it to the back out of the way.

  
  

  Stockton, New Jersey
  2020 nuCamp T@B 320S * Jeep Wrangler
  60,865 camping miles through the end of 2025

  
  

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• GPS_Jon Member Posts: 3

  April 5 edited April 5

  AnOldUR said:
  

  @GPS_Jon
  

  Another non-plumber person who used the rubber couplers rather than PVC glue.
  I kept the p-trap. Swung it to the back out of the way.

  
  

  I like your setup.  More room without spending money on the waterless trap. I used the Fernco couplers so I could rotate the sweep and not use a T. I might have gone with your approach if I saw it first. Either way, for the extra room in that cabinet it’s worth the modification. 
  
  I filled up the sink and pulled the stopper.  The sink drained quickly and most of the water went into the grey tank.  There was maybe two cups on the ground.  My black pvc pipe must not be seated in the tank.  I’ll have to pull the shroud and see if I can get eyes on it.  The plumbing I added had no leaks.  
  

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• ScottG Administrator Posts: 5,654

  April 6 edited April 6

  GPS_Jon said:

  ...
  I filled up the sink and pulled the stopper.  The sink drained quickly and most of the water went into the grey tank.  There was maybe two cups on the ground.  My black pvc pipe must not be seated in the tank.  I’ll have to pull the shroud and see if I can get eyes on it.  The plumbing I added had no leaks.  
  

  In light of this, I retract my earlier guess about the rubber flange. Given the amount of leakage I'd say your drain pipe has parted ways with your grey tank. Please report back what you find and, if applicable, how you fix it.
  
  

  2015 T@B Max S (320)
  2015 Nissan Frontier SV V6 4x4

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• pthomas745 Administrator, Moderator Posts: 4,509

  April 6

  Back in December, @jimcenname installed this "bottle trap" in his trailer.  Looks like a simpler install to me, someone with very limited plumbing experience.

  https://tab-rv.vanillacommunity.com/discussion/20115/replacing-the-kitchen-hepvo-drain-pipe-with-clear-removable-bottle-p-trap-t-b-400

  
  

  https://www.amazon.com/dp/B0FG7977MF/?coliid=I18HMIAD81K3ER&colid=3DJSJON9VK2CS&th=1

  
  

  Looks like this:

  
  
  

  2017 Outback

  Towed by 2014 Touareg TDi
  

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• jimcenname Member Posts: 343

  April 6

  pthomas745 said:

  Back in December, @jimcenname installed this "bottle trap" in his trailer.  Looks like a simpler install to me, someone with very limited plumbing experience.

  https://tab-rv.vanillacommunity.com/discussion/20115/replacing-the-kitchen-hepvo-drain-pipe-with-clear-removable-bottle-p-trap-t-b-400

  
  

  https://www.amazon.com/dp/B0FG7977MF/?coliid=I18HMIAD81K3ER&colid=3DJSJON9VK2CS&th=1

  
  

  Looks like this:

  
  
  

  It's still working well for me. No leaking. 

  2019 T@B400
  TV: 2017 Nissan Frontier SV 4X4
  Southern California
  Full-timer since 2019
  

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• GPS_Jon Member Posts: 3

  April 9

  The pipe was broken. The threads were still in tank. I had to split the threads to remove that part.  Off to the hardware store again.  lol 
  It wasn’t too hard to get it out.

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• Gomers2 Member Posts: 114

  April 14

  Fun fact: The 360 comes with a hepvo type drain (no P trap) in the bathroom sink. Not sure why, since there is a lot of space for a standard setup. 

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