RE: Changing water tank drain

[Garrett]

 
My water tank in under the dinette seat in the front  corner of the PU. It orginally had a drain inside that the only way to reach was to pop up and reach into a blind corner of the dinette seat and pull a plunger type valve.  Two problems with this is having to pop up to open or close the valve and often when pulling the plunger the drain tube would come out of the opening in the floor.  I tried to intall a longer drain tube that would extend to the front underside edge of the PU but where it turns to go through the floor the bend is too sharp and it kinks.  It will still drain but very, very slowly.  If I install a barb fitting elbow to make this turn I would have to increase the size of the hole through the floor to accomadate the hose clamp.  I am concerned this would allow road spray and/or critters to get into the PU.
 I am considering using CPVC pipe to go through the floor.  I would intall a barb fitting on either end of the CPVC so it would not be a rigid connection, but I am still concerned about the plastic pipe shearing off and flooding the PU.  Just looking for thoughts and suggestions.

[MtnCamper]

 Garrett

 

ORIGINAL:  Garrett
 
  If I install a barb fitting elbow to make this turn I would have to increase the size of the hole through the floor to accomadate the hose clamp.  

Why not just use some PVC glue, and glue it together? After all it s just a drain. Shouldn t contaminate anything.
 Put a clamp on the underside to keep it from going back up the hole. If you want to cover it, nipple with a hose barb, (short) then a pipe cap. If you can reach it easy.

[Garrett]

 Garrett
I do not think PVC glue will work on the plastic barb fittings.  If it did why would you ever use hose clamps.  This fitting will be between the tank and the drain valve so it will need to be watertight.
 

[MtnCamper]

 Garrett

 

ORIGINAL:  Garrett
 
 I do not think PVC glue will work on the plastic barb fittings.  If it did why would you ever use hose clamps.  This fitting will be between the tank and the drain valve so it will need to be watertight.
 
 

I thought it was just a drain, and no pressure involved. I think the glue would hold fine on a non pressure drain.
 

[Ab Diver]

 Garrett
Mike, if I have this pictured correctly, your tank drain goes through the floor, you want to move to a larger diameter pipe, and your concerned that if the larger pipe was PVC it might break. Correct?
 
 Why not just use galvanized metal pipe? It won t break, can be epoxied/bolted into place so it won t move and the hole will be sealed, all the usual PVC fittings will match up to MPT threads so you can have flexible tubing from your tank, AND you could add a ball valve at the end of the metal pipe so you can drain the tank from outside without having to pop the top.
 
 Or do I have the problem bass-ackwards?

[Garrett]

 Garrett
Yep, Galavanized will work just fine.  just had PVC on the brain.  thanks for the help

[popupcop]

 Garrett
My dad is a plumber and has been for 55 years.  I worked with him most of the time I was growing up, and still help him occasionally so I have some plumbing knowledge.
 
 I would use brass.  It is a little more expensive but will last much longer than galvanized.  Galvanized pipe will rust after a time.  In any case use some type of teflon tape or pipe joint compound to keep away leaks even if your are going low pressure!
 
 Mt Camper... PVC Glue causes PVC to bond/melt together through a chemical reaction.  It is not really a glue like Elmer s or gorilla glue.  Trying to glue barb fittings to a different type of plastic using PVC glue likely would work about as well as not using the glue at all.

[MtnCamper]

 popupcop

 

ORIGINAL:  popupcop
 Mt Camper... PVC Glue causes PVC to bond/melt together through a chemical reaction.  It is not really a glue like Elmer s or gorilla glue.  Trying to glue barb fittings to a different type of plastic using PVC glue likely would work about as well as not using the glue at all.
 

Ya, After thinking about it your right, Originally I thought Garrett was still going to use the valve as he does now. So the drain would have no pressure at all. But after rereading his post, I think he wants to eliminate the valve and just use a cap, or valve on the end. So I would probably solder together a copper drain pipe and add a swing valve at the end of it to drain. Then I would strap it down (or up) to the floor. Just so it wouldn t rattle.