Propane cylinder water drain-Problem solved

[Nebula]

Faced with the old problem of how to drain condensate from a propane bottle air reciever I have come up with a solution. I removed the valve and replaced it with a 3/4 BSP nipple, on to this I fitted a 4 way 3/4 BSP cross fitting. Into the top of the cross fitting I put a 3/4 - 3/8 reducer and into that a 3/8 BSP to 1/4 compression fitting. Before fitting the compression fitting I drilled out the inside of it so that a 1/4 copper pipe would pass right through.

I passed the copper tube right through the compression fitting, through the cross piece and down to rest on the bottom of the cylinder, I cut small notches in the end of the tube first so there was no chance of it getting blocked when in contact with the base of the cylinder. The other end of the 1/4 copper tube bends back down the outside of the cylinder and terminates with a valve. Opening the valve with the cylinder under pressure forces any moisture in the bottom of the tank out of the drain valve.

The left and righthand spouts of the cross fitting serve as air in from compressor and air out to workshop. Sounds more complicated than it actually was. Photos help explain.

 

[rtbcomp]

I used a similar method to make a gearbox oil dispenser, with a Landrover (2 axles, 2 swivels, gearbox, transfer box and overdrive) it saves a lot of hard work.

For draining my propane bottle air tanks - I mounted them upsidedown so the moisture goes out with the air and into a trap.

 

[the snooper]

could have just turned it upside down

 

[Nebula]

Why allow more water into the air when you can get rid of some at source? That's the reason air receivers have drain taps.

 

[rtbcomp]

It doesn't matter if you have a trap after the tank. Most regulators are fitted with one.

In my case the propane bottles are in parallel with the compressor tank so any water that collects in the bottles is pushed back into the receiver.

I suppose if your propane bottle is the only tank in the system then your method is better.

 

[drivewasher]

Good idea, I suppose the valve could be on top ot the cross piece so it's not flapping about near the floor and you can operate it fron high level.

 

[Nebula]

It could indeed. My plan is to fix the valve to a wall when the tank is in it's final position and run a pipe from the valve to outside the compressor housing.

 

[123hotchef]

I was thinking about turning my one upside down when I get round to fixing it all up

 

[Burdekin]

I just tig welded a 1/2BSP socket on the bottom for the drain and the same 1/3 from the bottom for the intake. I welded four small legs on the bottom for clearance, drilled a hole through one of the legs and fitted the drain pipe through that with a valve on the end.

 

[123hotchef]

good idea but I cant tig I guess I could get iron fittings and arc them on,

I did think about drilling and using a tap to cut a 1/2" thread

 

[Burdekin]

Stick welding them would be fine, just do a good prep for the weld so you get good penetration. My compressor only operates at 8bar so no great pressure. I welded the drain in flush with the inner edge of the bottle so all the moisture can drain away easily.

 

[123hotchef]

that's a plan then maybe I will try to drill and tap it first if that goes wrong I have the old fail safe of welding

 

[AndyStobbs]

good idea but I cant tig I guess I could get iron fittings and arc them on,

I did think about drilling and using a tap to cut a 1/2" thread

Malleable iron fittings weld like rubbish. Ends up being very porous. Stainless fittings are much better or proper mild steel bosses.

 

[123hotchef]

ah thanks they do sell weld on mild steel bosses dont they seen them somewhere before.

Any way just snapped my 26mm spanner trying to take the valve out.

Any tips on getting the valves out people?

 

[brightspark]

ah thanks they do sell weld on mild steel bosses dont they seen them somewhere before.

Any way just snapped my 26mm spanner trying to take the valve out.

Any tips on getting the valves out people?

yes a 2 lb hammer and 3 good batts on the side of the-valve and it will fall out, never fails

 

[123hotchef]

ha ha wont that dammage the threads though?

 

[brightspark]

ha ha wont that dammage the threads though?

only on the outlet valve not the ones in the bottle

 

[123hotchef]

ok thats on my too do list tomorrow will 1.5 batts work with a 4lb hammer

 

[Bill Edwards]

Malleable iron fittings weld like rubbish. Ends up being very porous. Stainless fittings are much better or proper mild steel bosses.

Or, just about anything welds better than the malleable iron ones! I learned the hard way, thankfully I had only ordered one - but it would not give an airtight weld no matter what, in the end it got the leaky weld sealed with braze. Horrible stuff, I'd sooner weld galvanised!

 

[123hotchef]

seen plenty of galved ones hate the smell and it always fizzes and spits on galv