Odd setup on emergency water tank

Hi all, first time poster.

I have a large water tank that I need to hook in to for both general potable water, and for fire suppression.

For fire suppression, it has a 4" female NPT outlet. I need to reduce this to 2 1/2" male NPT and install a gate valve. I am looking for a supplier for the reducer bushing, and the valve. I would prefer brass, but struggling so much that I'll take whatever I can get.


For the potable water aspect, I have 2" female NPT ports for both the inlet and outlet. Clearly for a domestic supply I do not need 2" pipe, so I'm happy to reduce that down.
However to make it more complicated, I need to be able to pass the pipe THROUGH the port, not just have connected to the outside.
The reason being that the inlet needs to have a float valve inside the tank (with a calmed inlet), and the outlet needs to have a floating pickup inside the tank.

I cannot find a fitting that will thread on to the port, but allow the pipe to pass cleanly through. I spent some time trying things like 1 1/2" PVC inside 2" PVC etc, but cannot find anything that fits tight enough.


Can anyone help me with the correct terms for these kinds of fittings, or a supplier I try?

This image describes the non fire aspect well.




Many thanks

are you looking for a "bulk head fitting" ?

http://agrimart.net/4-poly-bulkhead-fitting-tf400/?utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20-%20General&utm_term=1101601889240&utm_content=banjo


I would use all sch 80 plastic, then transition to what ever you want after the tank

Unfortunately not. The tank is galv steel, and the NPT threaded ports are already installed (welded on), so bulkhead fittings aren't what I want.

Basically I need a 2" NPT threaded adapter, to a 1 1/2" slip. The part I'm struggling with is one where the pipe can pass all the way through, instead of just hang off one side.

the reducer was a small "stop" to keep the pipe from sliding thru...dremel the stop away


or 2 1/2...you get the concept of my idea...will it work for you

if i were you i would look at if a sch 40 coupling fits into a sch 80 pipe

that kind of thing,,,basiclly,,grab some fittings and stick them in a pipe

on line will give you only id and od of pipe

and the socket size of fittings but not wall thickness of fittings,,,that is field tinker toy figureing


or...brass fitting and harris silflos brazing rod

make one

use a catfish/ turkey fryer burner , lay the fitting on it till it gets red hot and braze it

frodo said:

if i were you i would look at if a sch 40 coupling fits into a sch 80 pipe

that kind of thing,,,basiclly,,grab some fittings and stick them in a pipe

on line will give you only id and od of pipe

and the socket size of fittings but not wall thickness of fittings,,,that is field tinker toy figureing


or...brass fitting and harris silflos brazing rod

make one

use a catfish/ turkey fryer burner , lay the fitting on it till it gets red hot and braze it

Click to expand...

I hadn't thought of fitting schedule 80 & schedule 40 together considering different wall thicknesses; good idea, I'll try that next. I think I prefer that to the turkey fryer brazing, but I may get there yet

I'm going to head to a plumbing warehouse tomorrow in the hopes they'll have more things I can try that Home Depot have. I think if I was working with 3/4" or 1/2" HD would have a lot of options, but they carry way less fittings in the bigger sizes (understandable).

Thanks for the help so far!

Maybe a 2" x 1-1/2" wall seal nut on a 2" SCH 80 nipple. Same idea as installing a 1' gas line using an 1-1/2" adapter and wall seal. As long as I understand what you're trying to accomplish correctly.

I have progress, a 2" schedule 80 nipple takes 1 1/2" pipe all the way through just nicely, just a little pressure, so that will glue cleanly.

Now I just need to reduce the 4" female port to a 2 1/2" threaded male.

Thanks for the input!