Class A Customs Plumbing Example

This is an Example of plumbing for a trailer, you will need to verify your configuration for your unit.

All water tanks we carry must be vented, they are not pressurized tanks, allow air to move in and out when filling and emptying the tank. Do NOT fill the tank directly from a pressurized line (garden hose), this is not a safe option and will explode the tank.

~ Fittings ~




Where are the fittings located in the tank? What kind of fitting are in the tank?

Our Stock Tanks come with 4 fittings all located on the same side of the tank. Be sure to look at the tank photos and description to clarify fittings.


Can I cut a hole in the tank and glue another fitting in?

No, fitting are spun welded into the tank, friction between the fitting and the tank causes both to melt and permanently seal, no additional glues or sealants are used to install the fittings.

The residue left by putting the fittings in place is part of the material the tanks and fittings are made from and may spider crack or flake off over time, this in no way harms the tank or causes any usage issues.




Uniseal Fittings Now Offered for more information go to our Blog Post Custom Tank Fittings Now Available




~ Fill Dish ~   

What is a fill dish?

The fill dish is located on the outside of your unit so that you can easily add water to your tank without the need of opening a compartment or climbing under your unit. You can find the fill dishes in the Plumbing Category.

For adding water to the Water Tank you need a Gravity Fill Dish, the hose rests in the port it does not screw onto the port this allows you to place a garden hose into the Gravity Fill Dish port without making a sealed connection so the supply is not pressurized.   

For using water directly from a garden hose you need a City Fill Dish, the hose makes a sealed connection and the water supply is pressurized, you can not hook this to your water tank and you do not need to go through your water pump.


We carry Gravity Fill Dishes, City Fill Dishes and Combo Fill Dishes that have both gravity and city, the benefit of having both is you can have a water tank of fresh water but if you go to a location that supplies pressurized water (campground - fair - etc.)

you do not need to use your water tank supply of water you can simply use the water provided. Be sure to look at the provided

example plumbing diagram for more reference.


But what if I only turn the garden hose on half way?  

Customers who do this still explode the tank because you can not determine the pressure of the water flowing only the amount of water.


I am not using a fill dish how can I fill the tank?

We recommend you place a fitting in the tank that will allow you to rest the hose in to fill, not make a sealed connection, you can then cap this when not in use. You can use an elbow fitting to allow you the fill the tank to capacity, use an elbow with a screen secured over it to vent the tank.


Can I put a cap on and off of the tank?

If you are needing to use a fitting by adding and removing a cap, remember tank must be vented allowing air in/out during use, we recommend you place a fitting in the tank and a cap on that fitting in order to prevent damage to the tank fitting.