The gases necessary to fuel your burners and torches may be delivered by way of complex gas manifold systems or something as simple as a compressed gas cylinder, regulator and flexible hose assembly. All federal, state and local regulations must be adhered to whichever system is used. Prior to use all gas systems should be inspected for leaks and overall safe operating condition.
Both gas delivery systems will require the use of flexible tubing at the torch or burner. Burners are usually stationary on a bench top and may require only 2 -3 feet of tubing. The hand torch will be moved a great deal, however, and will require 8 - 12 feet of tubing on average. Much of the tubing we use at Elev8 is of the "twin-tubing" form with a protective woven overbraid or sleeve
(recommended).
Compressed Gases
Propane will be the fuel gases used typically when working borosilicate glass with propane being the most common and some systems using natural gas. A good torch and flame need pressures for the torch to work properly. Delivery pressure of 5-12 psi is recommended, depending on your torch and torch size. If your gas source is from a municipal (city gas) system, chances are you will be dealing with 5 psi or less and may need a pressure booster. You will still be able to work glass in the soft glass and borosilicate family, but will be limited to diameters of glass less than 51 mm, depending on the type of seal attempted.
Oxygen is always used as the mixing gas in scientific glassblowing to get the propane or natural gas flame hotter. Oxygen pressures range from 10 - 15 psi for most applications. Compressed air is not capable of producing the flame temperatures necessary for working borosilicate and quartz glasses.
Hydrogen is commonly used for working quartz or fused silica. Pressure ranges are adjusted to the type of seal and size of quartz being worked, but you will find 5 - 10
psi a good starting point.
Typical Gas Delivery System
Gas Source --> Regulator --> Delivery Line --> Torch or Burner. Safety and shutoff valves should be strategically placed in the distribution system. Many times the regulators can also be used to turn off the fuel or oxygen gases. It is recommended that all gas delivery lines come up from under the workbench to keep everything out of the way and save. Gas lines that hang from above or lay on top of the work surface will be exposed to flames and hot glass and is not desirable!
