dragon Posted April 9, 2015 Share Posted April 9, 2015 Ok, so the gas company is dropping off a 250 gallon propane tank tomorrow. They've decided to allow a high pressure line off of the tank, so long as I don't pipe it indoors (Luckily, it's right by my shop door and my forge and torch are both also by my shop door. Easy enough to open the doors and set things outside).What kind of pressure do I want on the high pressure side of things, keeping in mind future equipment expansion? I presently have a small 6x12 gas forge, with plans to make larger ones for when needed. I also have a few cutting and heating torches. The tubing from the tank to the high pressure outlet is 1/2 inch ID.The standard way they set things up is with 2 regulators, a high pressure regulator directly on the tank that they say is about 8-10psi (though in a different breath he said 5-8 psi, so I am unsure), and then the low pressure further down the line before going into the building. I *think* the connection on the tank is just a regular CGA-510 like you find on the bbq tanks. If so, should I try to convince them to let me put my propane regulator (3-35psi), or will 5, 8 or 10 psi be plenty for just about anything? Also, will another propane regulator added to the outlet of the high pressure line still function properly? Or do they require full tank pressure behind them to function correctly? It's my idea, if they let me user my regulator on the main tank, to just leave it at 10 psi unless I come across some application where I need a bit more, and then have another regulator on the outlet for finer adjustment to the forges or torches. The salesman expressed some concern that the low pressure regulator might not handle pressure above 10 psi from behind it, so I added another shutoff valve that would be used in the event of needing more pressure.I hope that all makes sense as phrased. Any major problems with the above that I ought to know? I do know there's a difference between gas flow and psi, but without flow gauges of some kind, I feel pretty limited in understanding it from that side of things. Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted April 9, 2015 Share Posted April 9, 2015 The shoeing scool I went to had a 15 PsI regulator on a 1/2 line running into the shop and each forge had its own regulator, as some forges needed a bit more or a bit less to reach forging temp. If they want to be difficult, buy your own tank out right and have it filled. My regulator goes from 0-35 psi.propain bulk tankes have two out lets, a direct pot to the top of the tank that is for gas and a dip tube for liquid. If the tank is yourse, then simply shut if the Valve, remove the regulator, install a higher rated one and go on about your business. If it is theire tank they wont like you tampering with it. If you dont know what you are doing please get a plumber or gas tech to look at it. At 1/2 a PSI gas leaks can be fatal, but at 35 psi it can be catastrofic Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted April 9, 2015 Share Posted April 9, 2015 A 1/2" line of Liquid Propane is a fire-ball, a death wish. Order the Propane Forge book that is available in many of the Blacksmith Book Suppliers.Read it slow enough to understand and retain a lot. Propane is normally rated in Water Column. Different than PSI.Propane gas comes from the surface area of the liquid propane inside the bottle. More surface area equals more gas quantity available, a 20 lbs propane bottle will freeze because the amount we are trying to draw off the small surface area creates a temperature differential. Rental companies sometimes hook 4 or 5 bottle together to get the larger surface area, so it won't freeze up with the amount of draw off the tanks.Have a gas, enjoy the journey.Neil Quote Link to comment Share on other sites More sharing options...
dragon Posted April 9, 2015 Author Share Posted April 9, 2015 Charles: The gas tech coming tomorrow has final approval over it all and I certainly had no intention of altering it beyond what they allow. That you had a 15psi line leading downstream to other regulators at the forges seems to answer my question about the pressure behind regulators, thanks!swede: Just to be clear, I'm not running the high pressure line directly into the forge or anything. I'm not even running it into the building. I'm putting another regulator at the outlet to further fine-tune the pressure for whatever I'm using. So what I'm gathering here, is that pressure is less important than the volume of gas that can evaporate from a tank at a time. So using higher pressures from a small 20lb tank is sort of compensating for lack of total gas flow at lower pressures? So with a bigger tank, I might be perfectly fine with lower psi so long as flow is otherwise unrestricted?I'll look into getting that book when I've got a chance. Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted April 9, 2015 Share Posted April 9, 2015 Preshure is the amout of "push" trying to deliver the gas, for house apliences we are talking somthing like 1/2 a psi, on my proforge the max recomended is 15psi. All things being equal 15 psi will diliver more propain molicules than will 1/2 a psi. Your gas forge will need a higher presure to operate than your kitchen stove. The minimum amout if presure you need is what ever the maximum preshure nedded by any propane apliance you have on the distribution line. So if you have a heater, you will need 1/2 a psi, wile a forge will need 5-15 depending on design. Dont know what a torch set needs. My suggestion is to show him the forge and have him adjust the tank regulator to supply it at welding temp pluss 10-20%Then you can regulate down with the forge regulator to adjust the forge temp. I would acualy consider a second line for any household type propane appliances. Not that you cant use a standard bbq type regulator on the hp gas line, but some ine that dosnt know your set up may get in trouble. Clearly mark the line and outlets with the rated PSI and intended use, and "not for house hold appliance use" just to keep some one else from plumbing in a heater to you forge fuel line. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 9, 2015 Share Posted April 9, 2015 With a 1/2" line you will have all the propane you could want to run several forges simultaneously. The psi set at a max of 10 means you won't have enough pressure to run naturally aspirated burners so you'll need gun burners. (blown)However if you're good at precision work you can get a naturally aspirated burner to weld at 10psi. only ONE of my four burners is that golden. It's the one that melts the 3,000f split hard fire brick floor. The easy way is to just use more burners per volume.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
dragon Posted April 9, 2015 Author Share Posted April 9, 2015 Thanks a lot, guys!It's sounding more like it'll be fine to use their regulator for the high pressure line, since I do use blown burners. The tech approved the setup, pressure-tested all the lines, and it's all good to go now. Quote Link to comment Share on other sites More sharing options...
mtforge Posted April 19, 2015 Share Posted April 19, 2015 My bulk tank has a 30# regulator at the tank. I then have a regulator at each forge or torch as needed. Quote Link to comment Share on other sites More sharing options...
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