Leak-proof Water Fill Hatch for On-board water OBW system

[jnack]

I have a 12 gallon valterra tank built into the storage system of my truck, it is filled via a gravity 1 1/4" standard fill tubing. I have the following fill hatch: https://www.amazon.com/gp/product/B0735LHQBD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Unfortunately, I was not able to mount the fill hatch significantly higher than the actual tank and as such I've noticed when off-roading some water spills out of the fill hatch (it's not really designed to be leak-proof, as these are typically for RV application.

I am looking for an alternative fill hatch that will connect to the 1 1/4" tubing via barb and hose clamp that is truly leak-proof. I have considered adding a 1 1/4 barb-barb ball-valve into the system though I imagine it would be simplier to just replace the fill hatch if I can find one that is truly leak-proof.

In anticipation of someone asking: yes the tank is vented, so when sloshing around and filling up, air can escape.

 

[IdaSHO]

Google search "deck boat fill"

 

[rayra]

Is the water sloshing out of the open vent line and not the cap? If you can gasket the cap it could be relatively easy to create a threaded bung for the vent hole, replacing the screen. Threading the pipe of the vent to either fit a 'found' bung fitting or plug, or even fashioning one out of some appropriately sized nylon rod and a tap and die set that is suitable for the vent pipe in the cap assembly. It would be very easy to make.

You could even drill the center of the new threaded plug with say a 1/4" bit, with a 1.8" crossing hole near the top, so you'd only have to unscrew the plug a couple turns to open the vent.

LOTS of ways to re-work that vent so it can be capped.

threaded vent bung at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[jnack]

Google search "deck boat fill"

i did. Did t see any that fit that size as a barb connection. Am I missing something?

 

[IdaSHO]

Not sure if you will find one for 1-1/4"

Most I've seen (and the one we run) is spec'ed for 1-1/2"

I use a simple barb reducer like this

Spears - PVC Reducing Insert Coupling - Insert X Insert | Reinders

www.reinders.com

 

[LandCruiserPhil]

40mm Black Water Filler, Locking Cap (ZADI)

WATER FILLERS (flush fitting nylon) (for 40mm hose) Manufactured from high quality impact resistant non-toxic Nylon. Pre-drilled for easy installation. The water fillers have short stems suitable for C.A.K. 40mm Supaflex hose & a 10mm connection for Tank vent. Our fillers are fitted as standard...

www.watertankswarehouse.co.uk

 

[Herbie]

My setup is similar, I have only a small rise above the tank to the fill port. I use a marine "deck fill" as others have suggested. Yes, it's 1-1/2" barb, but the 1-1/4" vinyl water tubing fits the larger barb easily after a little effort with the heat gun. EDIT: This was my first pass, but I found this kind of tubing too stiff for my short installation space, so I switched to a corrugated water pipe. Same process to heat it and slip it over the larger barb (with a little dish soap to lubricate), but I don't have a picture.



The deck fill port has a gasket on the cap and seals completely. The key for me has been a long vent line. The white tube on the right side here goes all the way up to the top of the van. (It didn't need to be that tall, but that was the easiest way to secure it out of the way and have it be more than 5-6" tall.)

The only problem I have with this filler arrangement is that I have to keep an eye on the water flow right at the end of filling the tank - since there's a shallow angle between the fill port and the tank bung, as the tank gets full I can get a little backflow if I'm trying to fill things up right to the top. If I only fill to the bottom of the bung on the tank, or if I slow down at the end, it's fine. (Having that valve on the RV water filler - the yellow thing in the photo - is key, since I can adjust the flow and stop it while watching the water level, without having to go back to the spigot to shut it off.)

 

[jnack]

Is the water sloshing out of the open vent line and not the cap? If you can gasket the cap it could be relatively easy to create a threaded bung for the vent hole, replacing the screen. Threading the pipe of the vent to either fit a 'found' bung fitting or plug, or even fashioning one out of some appropriately sized nylon rod and a tap and die set that is suitable for the vent pipe in the cap assembly. It would be very easy to make.

You could even drill the center of the new threaded plug with say a 1/4" bit, with a 1.8" crossing hole near the top, so you'd only have to unscrew the plug a couple turns to open the vent.

LOTS of ways to re-work that vent so it can be capped.

threaded vent bung at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

no, the vent line is only 3/8" ID and goes much higher than the tank (to the top of my shell), haven't had any wet spots by where it'ts attached to the shell thus why I believe it's coming from the fill cap

 

[jnack]

My setup is similar, I have only a small rise above the tank to the fill port. I use a marine "deck fill" as others have suggested. Yes, it's 1-1/2" barb, but the 1-1/4" vinyl water tubing fits the larger barb easily after a little effort with the heat gun. EDIT: This was my first pass, but I found this kind of tubing too stiff for my short installation space, so I switched to a corrugated water pipe. Same process to heat it and slip it over the larger barb (with a little dish soap to lubricate), but I don't have a picture.

View attachment 584388

The deck fill port has a gasket on the cap and seals completely. The key for me has been a long vent line. The white tube on the right side here goes all the way up to the top of the van. (It didn't need to be that tall, but that was the easiest way to secure it out of the way and have it be more than 5-6" tall.)

The only problem I have with this filler arrangement is that I have to keep an eye on the water flow right at the end of filling the tank - since there's a shallow angle between the fill port and the tank bung, as the tank gets full I can get a little backflow if I'm trying to fill things up right to the top. If I only fill to the bottom of the bung on the tank, or if I slow down at the end, it's fine. (Having that valve on the RV water filler - the yellow thing in the photo - is key, since I can adjust the flow and stop it while watching the water level, without having to go back to the spigot to shut it off.)


View attachment 584389

my fill hose is the ribbed version like this: is that the kindthat you went with? with the ribbing on it it didn't seem forgiving enough to fit around a 1.5" opening...

 

[Herbie]

Yep, something like that. I used a harbor freight heat gun and a glass bottle that had a tapered shape as a "mandrel" to stretch the material over as it warmed up. Got it close, then lubed up the deck-fill barb with dish soap and jammed it on, then added the hose-clamp. Zero leaks in the 2+ years since I installed it.