Shark Bite Valve for fresh water overflow

[Unlimitedmatt]

Just remember you MUST OPEN IT to use your water pump or tank damage can occur. Conversely you must open it to fill the tank or damage can occur too. I added a label to my nautilus panel to remind me. Overflow pipe is 3/4" pex. Mark (@boyscout) is correct on his suggestion. HD carries several models of this valve with different end configurations. Be sure you get the correct one.

Can you tell me what damage will happen by not opening this valve?

I 100% of the time boondock so I installed a small ball valve 2 years ago that I open when filling my fresh water tank. I then close it once the tank is full. I seem to forget to open it more times than not while camping.

My 2800bh has the fresh water fill on the curb side of the camper, so this is how I always fill it. It seems to me that the screw on cap for the filler is not air tight, but I am not positive.

[powerscol]

If left closed while filling you can bust the tank and cause structural damage from tank expanding and bending the frame holding it and possibly buckling the floor.

If left closed it can collapse the tank as the pump draws water causing similar issues.

One question - does your trailer have a gravity fill port. If it does check to be sure the cap vent is working (if it has one). This can mitigate the usage suction on the tank, but would need to be off to prevent tank bursting under fill and even thin there could be issues.

[Unlimitedmatt]

If left closed while filling you can bust the tank and cause structural damage from tank expanding and bending the frame holding it and possibly buckling the floor.

If left closed it can collapse the tank as the pump draws water causing similar issues.

One question - does your trailer have a gravity fill port. If it does check to be sure the cap vent is working (if it has one). This can mitigate the usage suction on the tank, but would need to be off to prevent tank bursting under fill and even thin there could be issues.

Yes, my camper does have a gravity fill port. The gravity fill port does have a vent but in GD infinite wisdom, the vent does not have a hose installed and there is a blob of silicone plugging the vent. My assumption is they are not using the vent so they could use the same overflow setup as the rest of the fleet.

[PappaJohn]

I have had RVs for nearly 50 years from truck campers, pop up trailers, conventional and fifth wheel trailers and class A diesel pushers. They have had both gravity fill and pressure fill water tanks and I have never has an issue with loosing fresh water while travel before.

Why are these GD trailers different?

[powerscol]

The cap itself may be vented. Take it off and look at the inside. If vented there will be a small center hole and you should be able to blow and suck through it. If not you can drill your own hole and put a screen over it. This will prevent issues when using the pump and protect the tank from collapsing. It will not protect from filling due to its size.

[powerscol]

Its the way the plumed the vent.

[PappaJohn]

Its the way the plumed the vent.

I understand that but why? I have not looked but it appears they run the vent tube directly out and down instead of running it up above the tank first and then down. With the tank being close to the floor, this might require them running the tube up into a cabinet a few inches before running it out the bottom.

For folks that dry camp, this was a poor way for them to save a couple of bucks.

[dkayak]

The cap itself may be vented. Take it off and look at the inside. If vented there will be a small center hole and you should be able to blow and suck through it. If not you can drill your own hole and put a screen over it. This will prevent issues when using the pump and protect the tank from collapsing. It will not protect from filling due to its size.

Or you can drill a few tiny holes in the cap. It takes very little vent area to prevent a vacuum because air flows so much easier than fluid (just like when you crack open the vent on a gas can to get a smooth pour). With small holes you don’t need to add a screen because you’re creating one. The cap itself doesn’t seem to be airtight either.you know you’re in good shape when you can close the ball valve on the overflow, open the slide gate, and dump a huge smooth stream.

[rootusrootus]

I have had RVs for nearly 50 years from truck campers, pop up trailers, conventional and fifth wheel trailers and class A diesel pushers. They have had both gravity fill and pressure fill water tanks and I have never has an issue with loosing fresh water while travel before.

Why are these GD trailers different?

It must vary by trailer model and tank design/orientation/whatever. I don't have this problem on my trailer.

[Thorvald]

I have had RVs for nearly 50 years from truck campers, pop up trailers, conventional and fifth wheel trailers and class A diesel pushers. They have had both gravity fill and pressure fill water tanks and I have never has an issue with loosing fresh water while travel before.

Why are these GD trailers different?

They are not, I had the sample problem on all my Jayco’s. Had to clamp the vent lines before travelling with full fresh water tanks.