twistedstang
Well-known member
my woodsplitter has lots of black iron pipe fittings on it, and it runs at 2750psi
Hopefully sch 160 seamless. Unfortunately, sch 10 looks the same on the outside.
Oops. Old thread
my woodsplitter has lots of black iron pipe fittings on it, and it runs at 2750psi
The pipe I'm not super worried about but what PSI can you run the fittings at?!
I'm building a liquid propane flame projector for a pyro music firework show. They want a 100ft+ height flame for at least 11 seconds, pretty tricky. They tried a bunch of commercial flame projectors but none of them could go that big.
I found a 33LB forklift propane tank dirt cheap. The stock liquid propane output valve has SUPER slow flow. So instead of using the stock valve I took out the pressure relief valve and put a tee where it screwed into the tank (3/4" NPT), screwed the pressure relief into the tee and put a 500psi rated stainless steel full port ball valve on the other tee port. All the flow you could ever want (run the tank upside down for liquid, right side up for vapor).
The scary part is liquid hammerThere's a digitally controlled solenoid flow valve (on/off only, and it's pretty much instant) and with the ball valve fully open (running at full anger) I'd imagine there's going to be big liquid hammer when it closes!
They make a soft close solenoid valve but I wouldn't be able to use ONLY that valve as the flames dance to music for a bit before the big flame and need instant on/off for little fireball puffs. I think I could install BOTH valves (in series even) so during the music I can use my existing quick open/close valve, then during the full anger run I can lock the quick valve open and use the slow close valve to send up the big flame.
Another issue is the fittings get really cold when I run it at full anger. Does temperature effect how much pressure the fittings can take? I'm talking super cold like as in -44c/-47f. After the ice fell off the fittings the first time I used it they rusted almost instantly.
Where can you get beefier fittings? I found a shop selling stainless steel fittings and pipe but they said they are only rated to 150psi!?? They could special order me some 200psi rated ones but they wanted crazy cash for them.
The first time I ran it at full anger the ball valve cracked where the input threads are (on the high pressure/tank side). Luckily it wasn't a large leak and I was able to turn off the pilot light before it ignited. I had to vent all the gas out of the tank to replace the ball valve. I believe it cracked due to the huge amount of thrust from the liquid leaving the solenoid flow valve. It put angled pressure on the pipe and the ball valve is closest to where a pivot point would be so experienced a ton of bending force. I'll have to make sure I super support the solenoid flow valve and piping so no physical pressure is applied to the pipe/fittings.
Let me know where I can get beefier fittings if anywhere. Brass or stainless would be nice (to stop them from rusting instantly). Would like to avoid galvanized so no flakes make it into my control valves.
If my regulator ever fails we'll find out real quick! Nitrogen (3000psi) fed directly into the propane tank at 175psi (3/4" port from the nitrogen tank, 3/4" in/out port on the regulator, 3/4" jackhammer hose, 3/4" inch port directly into the forklift propane tank). Common practice in hot air ballooning (nitrogen injection).
And yeah yeah, I know, it violates the cert of the tank and probably a ton of other rules too.
LETS COOK!
-Jamie M.
Oh baby, that's what I needed to know! McMmaster Carr has a bunch!You would want 3000# forged fittings. And yes, if the system could refrigerate, you want fittings and pipe that can handle it.
No way, too much good info in hereIs it time to put this thread back to sleep before reviving it yet again in another 3 years?
The pipe I'm not super worried about but what PSI can you run the fittings at?!
I'm building a liquid propane flame projector for a pyro music firework show. They want a 100ft+ height flame for at least 11 seconds, pretty tricky. They tried a bunch of commercial flame projectors but none of them could go that big.
I found a 33LB forklift propane tank dirt cheap. The stock liquid propane output valve has SUPER slow flow. So instead of using the stock valve I took out the pressure relief valve and put a tee where it screwed into the tank (3/4" NPT), screwed the pressure relief into the tee and put a 500psi rated stainless steel full port ball valve on the other tee port. All the flow you could ever want (run the tank upside down for liquid, right side up for vapor).
The scary part is liquid hammerThere's a digitally controlled solenoid flow valve (on/off only, and it's pretty much instant) and with the ball valve fully open (running at full anger) I'd imagine there's going to be big liquid hammer when it closes!
They make a soft close solenoid valve but I wouldn't be able to use ONLY that valve as the flames dance to music for a bit before the big flame and need instant on/off for little fireball puffs. I think I could install BOTH valves (in series even) so during the music I can use my existing quick open/close valve, then during the full anger run I can lock the quick valve open and use the slow close valve to send up the big flame.
Another issue is the fittings get really cold when I run it at full anger. Does temperature effect how much pressure the fittings can take? I'm talking super cold like as in -44c/-47f. After the ice fell off the fittings the first time I used it they rusted almost instantly.
Where can you get beefier fittings? I found a shop selling stainless steel fittings and pipe but they said they are only rated to 150psi!?? They could special order me some 200psi rated ones but they wanted crazy cash for them.
The first time I ran it at full anger the ball valve cracked where the input threads are (on the high pressure/tank side). Luckily it wasn't a large leak and I was able to turn off the pilot light before it ignited. I had to vent all the gas out of the tank to replace the ball valve. I believe it cracked due to the huge amount of thrust from the liquid leaving the solenoid flow valve. It put angled pressure on the pipe and the ball valve is closest to where a pivot point would be so experienced a ton of bending force. I'll have to make sure I super support the solenoid flow valve and piping so no physical pressure is applied to the pipe/fittings.
Let me know where I can get beefier fittings if anywhere. Brass or stainless would be nice (to stop them from rusting instantly). Would like to avoid galvanized so no flakes make it into my control valves.
If my regulator ever fails we'll find out real quick! Nitrogen (3000psi) fed directly into the propane tank at 175psi (3/4" port from the nitrogen tank, 3/4" in/out port on the regulator, 3/4" jackhammer hose, 3/4" inch port directly into the forklift propane tank). Common practice in hot air ballooning (nitrogen injection).
And yeah yeah, I know, it violates the cert of the tank and probably a ton of other rules too.
LETS COOK!
-Jamie M.
There's no "air" in the propane tank so technically it can't explode. It has a pressure relief valve even! The 3000psi from the nitrogen tank wouldn't even make it to the propane tank (if the regulator failed) before the rubber line would burst. I think the risk is pretty low of an explosion.I will put this as nicely as I can, but as you are talking about a "show" I can only assume you will be placing others at risk with this potential bomb you are building. From your post you clearly have no idea regarding even the base concepts of what you are talking about building. I would say step away from this project before you get your self, or more worryingly someone else killed.
It is good to go. Remember it has a safety factor as well. I have seen sched 40 taken to 2000 psi.

I wouldn't want to be around that installation for too long.
Tommy
HD rated theirs lower because they don’t trust China.
Seriously, I’d try to find something US made. Guys where I used to work used steel hydraulic tubing because they could get it cheaper than the black pipe. If it holds 3000 psi of hydraulic pressure, it’ll hold 150 psi of air.
There's no "air" in the propane tank so technically it can't explode. It has a pressure relief valve even! The 3000psi from the nitrogen tank wouldn't even make it to the propane tank (if the regulator failed) before the rubber line would burst. I think the risk is pretty low of an explosion.
Because of the size of the fireworks involved there is a large distance between the crowd and any of the equipment. Everything is ignited remotely so even staff will be far away. The flame projector is the last thing in the show so no worries about it igniting anything else either.
A member here sent me an awesome PM with some new design ideas to keep the propane tank far away from the flame using soft lines to run to the flame tube, and that will stop any issues of physical pushing on the ball valve/pipes etc. Should be a much more reliable and safer design. Can't wait to test it.
-Jamie M.

I'm going to be running this 300 psi hose, rated down to -40f, from the propane tank to the flame tube (should have 175psi in it): https://www.mcmaster.com/hose/hose-...ize~3-4/air-hose-with-male-threaded-fittings/Perspective: PCP pellet air rifle is at 3000-4000 psi done with hand pump. So 150-200 psi black pipe air line seems like no big deal.
