~ Fittings ~


Uniseal Fittings Now Offered that allow users to place fittings where needed.
If you are a manufacturer or OEM needing custom fittings please contact sales for more information, minimum quantity of 50 tanks will apply.

 





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.


 


 




Is that a fitting or a clean-out on the side?

Each tank will come with at least one vent hole made during the manufacturing process, a permanently mounted patch is placed over this hole this is not a fitting and does not unscrew.






~ Plumbing ~


Have a certified technician install all parts to prevent product damage and personal injury.


All water tanks we carry must be vented, they are not pressurized tanks.

You must 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. We recommend using a fill dish to allow for gravity feeding of the tank, please review our plumbing example for more information.

 

 



What fittings will I need?

This will depend on how you are setting-up your tank and will vary by application. Please view our Plumbing Category for information on loose fittings we carry.


At this time Class A Customs only installs the following fittings into our Fresh / Gray tanks

.5" NPT Female

1.5" NPT Female

1.25" Outer Diameter x 2" Long Smooth Pipe (Boss Fitting)


It is recommended to use plastic male fittings with plastic female fittings to avoid damaging the threads, metal thread fittings can crush the plastic threads.




1.25 hose hose can be used with the gravity dishes and spouts/boss fittings on tanks.
1.25 hose does not fit the Loose Fitting / Fixture - 1.5" Thread x 1.25" Hose Barb Fitting - Gray


1.375" hose can be used with the fill dishes and the Loose Fitting / Fixture - 1.5" Thread x 1.25" Hose Barb Fitting - Gray
1.375" hose can not be used with spouts on tanks.








1.25 hose hose can be used with the gravity dishes and spouts/boss fittings on tanks.
1.25 hose does not fit the Loose Fitting / Fixture - 1.5" Thread x 1.25" Hose Barb Fitting - Gray


1.375" hose can be used with the fill dishes and the Loose Fitting / Fixture - 1.5" Thread x 1.25" Hose Barb Fitting - Gray
1.375" hose can not be used with spouts on tanks.




Uniseal Fittings Now Offered that allow users to place fittings where needed.






National Pipe Threads (NPT)
Pipe sizes do refer to physical dimensions, but the plumbing industry standard for the sizes of pipe is not always as straight-forward as measuring the pipe. Measuring the pipe will oftentimes mislead you into choosing the wrong pipe, so do take care. The "pipe thread size" as shown in column 3 of the table below is measured and based on the inside of the pipe. But, to actually determine the size of a pipe, the outside diameter of each pipe or fitting must be measured and compared to the table for size identification. For example, a 3/4" NPT pipe thread has an outside diameter of 1.050 inches. Each thread size has a defined number of threads per inch (TPI). The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI (threads per inch) and OD (outside diameter) of the thread are required for positive identification of thread size because several sizes have the same TPI.

Male threads: Measure the outside diameter of the large portion of the thread at "A"; Find figure nearest this dimension in column 1 or 2 of chart. The dimension in column 3 will be your nominal pipe thread size.


Female Threads: Measure top diameter of thread at "B"; Find figure nearest this dimension in column 1 or 2 of chart. The dimension in column 3 will be your nominal pipe thread size.


Q."What does 'nominal' mean?"
A. Nominal is the term used to describe pipe and fitting measurements in plumbing. Nominal refers to the inside diameter of the pipe which varies by wall thickness of the pipe.

Q."Ok, so IPS pipe sizing isn't actually a dimension. So what about the fittings?"
A. Pipe fittings are "sized" by the "size" pipe they fit. So, for example, a 1/2" IPS fitting would fit 1/2" IPS pipe.


National Pipe Threads (NPT) have tapered threads. These are the most common threads used for general purposes. NPT threads are designed with a 60 degree thread angle, and are used for joining and sealing pipe to fittings in low pressure air or liquids and also mechanical applications. The tapered thread is 3/4" over one foot of length. Tapered threads are deeper at the end of the pipe and are increasingly shallower the further they are from the end of the pipe. The taper on the pipe only allows the pipe to screw inside the fitting until it is forced to stop because of the taper. The distance the pipe can be screwed into the fitting is specified by the ANSI standard. After tightening with a wrench the threads may have slight spaces between the pipe and fitting which could cause a leak so a pipe sealant must be used to ensure any gaps are filled.

The Dry-seal thread (NPTF) also have tapered threads. NPTF threads are used when the application is such that pipe sealing compounds may fail due to higher heat or pressure than normal NPT threads can withstand. The threads are designed to seal mechanically by slightly, but sufficiently, crushing the threads when tightened with a wrench. This allows for joining the pipe and fitting without sealants.

The NPT and NPTF threads can be interchanged if sealants such as PTFE tape or suitable pipe joint compounds are used. None of the other thread standards are fully interchangeable (GHT, NST, BSPT, NPSI, etc.) Female NPT threads can be designated as "FPT" or "FIP" and male NPT threads can be designated as "MPT" or "MIP".

National Standard Free-Fitting Straight Mechanical Pipe Threads (NPSM) have straight threads which are only used for joining. A washer or gasket is needed to seal this type of threaded connection.

There are also three less common thread types used in the plumbing industry. The Garden Hose Thread (GHT) and the Fire Hose Thread (NST) have coarse threads. The seal is made with a gasket or washer and are used mainly for attaching (joining) hoses to valves quickly, without the use of a wrench. The British Standard Taper Pipe Thread (BSPT) has a 55 degree thread angle (NPT are 60 degree) and is used internationally as a standard thread for joining steel pipes.



Can I stand the tank with the fittings facing up?

Yes, tank can be placed on any side be sure to brace the tank. In order to get water from the bottom of the tank run a food grade pipe down inside of tank, do not use hose as this will curl.




~ 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.


~ Monitor Panels & Water Tank Probes ~


Water Tank optional Installed Water Tank Probes, Loose probes are available for customer installation.

For Step-by-Step Photos visit our Blog Post Water Tank Monitor Probes



Monitor Tank Installation Help




~ Installing & Bracing ~


The tank looks like the side is bowed, is it safe?

Due to the manufacturing process all the tanks especially the larger in size will have a bowing to the walls, when the tank is filled the tank will expand out removing the inward bow, we recommend laying all tanks on a level surface (this can be angled) and bracing the tanks. For larger tanks it is recommended to brace all side walls with plywood or metal, we do not recommend using ratchet straps on the tanks alone as this is a large amount of weight on a thin strip and may cause cutting into the tank.


Tank Average Thickness

All tanks will vary on thickness but on average they are .219 or 7/32" thick.


Can I stack the water tanks on top of each other?

No, do not place anything on the tanks, if you need to stack the tanks you will need a weight bearing shelf between them.


Do I need to brace the water tank?

It is recommended to brace all side walls with plywood or metal, we do not recommend using ratchet straps on the tanks alone as this is a large amount of weight on a thin strip and may cause cutting into the tank.

 


 

Can I stand the tank with the fittings facing up?

Yes, tank can be placed on any side be sure to brace the tank. In order to get water from the bottom of the tank run a food grade pipe down inside of tank, do not use hose as this will curl.

 


Can I mount the tank under the trailer?

For those getting inspections you will need to verify with your local health department if you are allowed to place the tank outside of your unit. For all other applications we recommend having the tank sit on a level surface such as plywood or sheet metal then bracing it with bars or straps, it is helpful to fully enclose the tank to prevent damage from rocks and debris during travel. Be sure you check clearance to avoid having the tank removed on a speed bump or curb.





Can I hook more than one tank together?

Yes, you will need to check with a certified plumber to see what fittings and set-up will work best for your unit, remember to vent each tank.





Customer will measure and determine where inlet/vent will be placed on Black Waste Tank.
Use correct size hole saw bit in order to drill a hole in the tank and place rubber grommet in hole. Rubber grommet will secure inlet/vent pipe with no adhesives needed.




Included are a few short videos displaying the grommet installation process.