No vent line on water tank

Mark2x2 · 10-23-2012, 10:36 PM

I was wondering why my Cherokee 23DD water tank was hard to fill. Was looking at filler from the back side under a kitchen cabinet and noticed no vent tube at all. Looking under the camper I see no easy way to add vent line.
My thought to make filling easier was to make a smaller diameter fill tube with a hose connector I could snake into the tank. Then connect the water filler to it and hope the air would vent out around my fill tube.
Any better ideas or reasons this would not work?
Thanks,
Mark

Fire Instructor · 10-23-2012, 10:46 PM

Take the cap off of your filler. There should be a small vent (dime size). Run a rubber tube from the back side of that vent to the high-point plug on your tank. You may have to drill and tap that high-point.

Mark2x2 · 10-23-2012, 10:54 PM

Was hoping not to drop the tank. There is spray foam around stuff, looks like a bugger to drop tank.

Fire Instructor · 10-23-2012, 10:58 PM

Can you access the side, right next to or slightly above where the fill pipe enters? That's where my vent is tapped in.

Dave_Monica · 10-24-2012, 10:18 AM

There has to be a vent line on the tank or it won't fill or empty properly.

If there's not a vent line (1/2" tubing) right beside the filler cap, the tank will have a vent/overflow line off the top of it.

Dave

TURBS · 10-24-2012, 10:28 AM

As Dave said it has to have a vent line.

My tank takes 20 to 30 minutes to fill as I just trickle it in.
If I don't and open hose to full blast it belches and farts back to no end.
The water flow in on full blast is more than air can escape back out.

This what you need!

http://m.campingworld.com/browse/sku...=31795&rewrote

Or this .
https://images-na.ssl-images-amazon....500_AA300_.jpg

F and E Damp · 10-24-2012, 10:51 AM

With no city hook-up and the water pump turned off, maybe just opening one of the cold water faucets woul help?

comfun1 · 10-24-2012, 11:28 AM

The 2012 Cherokee Grey Wolf 21rr (and probably many other models) has no vent tube. It has a vent on top of the water tank but does not come from the factory with a hose. The fresh water fill has a vent beside it that has been plugged at the factory. It is a relatively easy job to remove the plug and add a piece of clear vinyl tubing from the tank to the filler vent. I learned this on this forum. It was hard to believe so I called the factory and they confirmed it, I added the tubing myself.

TURBS · 10-24-2012, 12:28 PM

Quote:

Originally Posted by comfun1

The 2012 Cherokee Grey Wolf 21rr (and probably many other models) has no vent tube. It has a vent on top of the water tank but does not come from the factory with a hose. The fresh water fill has a vent beside it that has been plugged at the factory. It is a relatively easy job to remove the plug and add a piece of clear vinyl tubing from the tank to the filler vent. I learned this on this forum. It was hard to believe so I called the factory and they confirmed it, I added the tubing myself.

But I gather his issue is believing there is not one so ever which is why it fills slow or belches back.
Meaning no provision at all for a vent regardless of having a hose or not

Turbs

Fire Instructor · 10-24-2012, 12:43 PM

There is a very basic hydraulics problem in the way that these systems and other water systems are designed to work. Water filling the tank displaces air. Water being drained from the tank is displaced by air. Whichever is more restrictive in flow becomes the limiting factor. Ever try to pour from you 5-gallon water jug, but have the water flow limited because the 1/8" vent wasn't letting enought air in? The same thing can happen (both ways) in your RV water tank.

If your water pump can pull more water than the vent will allow air to replace (which may be the case in some of the restricted vents that we aare talking about), than water flow will be restricted. I've seen folks go to a larger capacity pump so that they can get a mbetter shower, with no sucess. Likely becoase it couldn't pull or push more water through the 1/2" pipes, nor could air enter the tank quickly enough. If water in-flow can greathly exceed air release, then system components that were not designed to be pressurized may actually have pressure and fail.

It's interesting to compare water tanks in RV;'s vs water tanks in fire apparatus. Fire apparatus manufacturers are required to install a significantly LARGER vent, than the fill pipe for a water tank. This is to ENDURE that he tank never gets "pressurized" or pulled into vacuum, causing damage to tank or fittings. Yet in RV's, we typically see tank vents no larger than 1/2" OD, with a 3/8" worikn opening at the fittings....

TURBS · 10-24-2012, 01:03 PM

Quote:

Originally Posted by Fire Instructor

There is a very basic hydraulics problem in the way that these systems and other water systems are designed to work. Water filling the tank displaces air. Water being drained from the tank is displaced by air. Whichever is more restrictive in flow becomes the limiting factor. Ever try to pour from you 5-gallon water jug, but have the water flow limited because the 1/8" vent wasn't letting enought air in? The same thing can happen (both ways) in your RV water tank.

If your water pump can pull more water than the vent will allow air to replace (which may be the case in some of the restricted vents that we aare talking about), than water flow will be restricted. I've seen folks go to a larger capacity pump so that they can get a mbetter shower, with no sucess. Likely becoase it couldn't pull or push more water through the 1/2" pipes, nor could air enter the tank quickly enough. If water in-flow can greathly exceed air release, then system components that were not designed to be pressurized may actually have pressure and fail.

It's interesting to compare water tanks in RV;'s vs water tanks in fire apparatus. Fire apparatus manufacturers are required to install a significantly LARGER vent, than the fill pipe for a water tank. This is to ENDURE that he tank never gets "pressurized" or pulled into vacuum, causing damage to tank or fittings. Yet in RV's, we typically see tank vents no larger than 1/2" OD, with a 3/8" worikn opening at the fittings....

My point exactly!
Also water going down small fill tube will draw in air as well.

Turbs

Mark2x2 · 10-24-2012, 10:28 PM

Quote:

Originally Posted by f1100turbo

As Dave said it has to have a vent line.

My tank takes 20 to 30 minutes to fill as I just trickle it in.
If I don't and open hose to full blast it belches and farts back to no end.
The water flow in on full blast is more than air can escape back out.

This what you need!

Secure-Fill - Snl Products SNL1SF - Faucets & Inlets - Camping World

Or this .
https://images-na.ssl-images-amazon....500_AA300_.jpg

Ron,
That is exactly what I was talking about! The fill tube from the outside of the camper running into the tank is about an 1" in diameter, this device is a smaller diameter, the water will go directly into the tank. The air should escape between the two tubes.

The Camping World one looks like the way to go. The Amazon one is what I had in mind to assembly.
Thanks,
Mark

TURBS · 10-24-2012, 10:45 PM

Quote:

Originally Posted by Mark2x2

Ron,
That is exactly what I was talking about! The fill tube from the outside of the camper running into the tank is about an 1" in diameter, this device is a smaller diameter, the water will go directly into the tank. The air should escape between the two tubes.

The Camping World one looks like the way to go. The Amazon one is what I had in mind to assembly.
Thanks,
Mark

That should make your life easier!

Let me know if that works for ya!

Turbs

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