A Little Known Fact About Acetylene Gas and Heating Tips
What is this fact?Only so much acetylene can be drawn off of an acetylene gas cylinder in a set period of time.Unlike oxygen where you can turn it up about as much as the regulator will allow acetylene has different properties. The withdrawal rate of an acetylene cylinder is 1/7 of the cylinder contents per hour.
OK... now what does that mean?Heating tips have a specification as to how much acetylene is required to be properly used. For example the Victor MFA-6 tip requires 14 cubic feet per hour minimum to 40 cubic feet per hour maximum.Taking the withdrawal rate of 1/7 or .143 x the size of acetylene cylinder lets say a B acetylene of 40cf .143 x 40 = 5.72 cfh this would not be enough acetylene to properly operate the rosebud.
The next acetylene cylinder size larger would be a #3 with 74cf. Multiply .143 x 74= 10.58 which still does not supply enough acetylene. The next is the #4 acetylene which have approximately 104 to 140 cf of acetylene. Again multiply the cubic footage of the cylinder (written on the shoulder of the #4 cylinder) for demonstration purposes 130cf 130 x .143 = 18.59 which is enough to properly operate the heating tip. An easy way to figure the size of acetylene cylinder you need is to multiply the amount of acetylene needed to operate the heating tip by 7 or for this example 14 x 7 = 98cf. Minimum
Acetylene is vaporized from the acetone in the cylinder at the rate of 1/7 of the contents per hour. What happens if it is exceeded? Acetone is drawn from the cylinder and drawn into the torch. Not only is acetone hard on the o-rings on the torch but the acetone that helps stabilize the acetylene is reduced.
How can you tell if you don't have enough acetylene to run the rosebud properly? The rosebud can become hot, make popping noises or even make a whistling sound. The popping sound is the result of an explosion taking place inside the heating tip. If there isn't enough acetylene being supplied to keep the flame outside of the tip the flame will actually go inside of the rosebud and into the handle. If flashbacks are not on the torch it can even reach the cylinders and create a fire or even explosion.
Victor Acetylene and Oxygen Gas Torches are the Industry Standard
Note that these devices reduce the volume of gases available at the tip/nozzle.
Worst Case Scenario for Acetylene Cylinders
dangers of acetylene.What I do want you to take notice of is the individual explosions. These are single cylinders going off one at a time. Acetylene cylinders are equipped with a fuse plug that are designed to melt at 212 degrees allowing for the acetylene to escape so it will not increase cylinder pressure and explode. In some of the flames you can see this happening. There will be an intense, fast moving flame from the middle of other flames.
INFO: Acetone (systematically named propanone) is the organic compound with the formula (CH3)2CO. It is a colorless,volatile,flammable liquid,and is the simplest ketone. source - wikipedia
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MC Acetylene Tank
If you are wondering what the MC stands for it is taken from when motorcycles used acetylene gas for headlamps. MC=Motorcycle
B Acetylene Tank
If you have an acetylene regulator that does not fit this cylinder there are adapters available or you can take your regulator to a welding distributor and they can install the proper fitting on the regulator to match the B acetylene.The B size like the MC acetylene are mainly used for small brazing jobs for the hobbyist or professionals in heating and air conditioning where portability is crucial.Like the MC acetylene cylinder the B does not need a cylinder cap due to its low volume of gas.