Braising brass fittings into steel tanks.

Main Train Horns
1

Well it’s proving impossible to find the right thread type. I neas so I was wondering could I use a npt brass plug into my bsb thread on my air tank

I will then braise/silver solder them to get a perfect seal will this work?

2

I should be right now. Ordered the correct fitting however adding a touch of solder does not sound like a bad idea either way.

Bassicly I have a k5la fed from a 5 gal tank with 1/2" Id line. I’m going to plumb 2 extra 5gal tanks I have here with 1/4" air line into 2 spare ports on my tank. However this allows 12 extra fittings/bungs were air could escape.

3

I wouldn’t be so sure about that. Firstly, there’s no need for it… especially on a tapered thread. Using a thread sealant (either polymer liquid like Loctite 5452, or even just Teflon tape) would be far quicker easier and more durable.

The heat needed to braze effectively against potentially incompatible metals could cause more issues than what is solves (e.g. warping of the threads or housing which may end up destroying your tank or compromise the fitting all together).

4

I would not weld, braise, or otherwise heat a tank without pressure testing it afterwards.

Use Loctite 545.

5

Cheers guys. What about drilling out the old tiny 1/4" fittings and welding in a steal 1/2" fitting.

I’m worried what the k5la will sound like when my main tank runs out and as the 2 other tanks will only be 1/4" still at 200psi though

6

Uhm… see above comment from ear2ear. Unless you fancy pressure testing your tanks again, I’d stay away from the welder.

If you have linked tanks, pressure will equalise within the system. It’s not like you run your first tank dry and then the others will top it back up. 1/4" will still flow plenty of air, especially if you’re only using a short section.

You seems to have plenty of spare ports, so If you have concerns why not just run another joiner between the tanks?

7

I have heaps of spare ports on the new tanks, non on the bigger tank.

I find with my system I get 5sec of constant beeping before u can here the horn dieing.

I know the system will equal out but not as quick as I can drain it.

Dbo u have a decent system so u know how hungry the k horns can be.
But I’ve been telling the guys at work it’s like smashing a hole in the side of a water tank and try to use a hose to keep it full yes in theory it should be the same but 2 x 1/4 should flow half that of my 1/2" from memory.