Chapter 2 Installation
2-12
AA-6800/6650 Instruction
2.3.6 General Precautions for Handling Gas Cylinders
Handle the cylinders carefully, observing the following precautions.
(1) Before installing a pressure regulator on a cylinder, it is always necessary to blow away any dust in the
cylinder outlet.
(2) When opening the cylinder main valve, turn the secondary pressure control handle sufficiently
counterclockwise, and after checking that there is no one standing on the outlet side, gently open the valve
with a cylinder handle.
(3) In the case of nitrous oxide, hydrogen, argon, oxygen, etc., open the cylinder main valve sufficiently. With
acetylene, do not turn the cylinder main valve more than 1.5 turns in order to prevent the acetone or DMF
(dimethylformamide) inside from flowing out.
(4) When using a nitrous oxide-acetylene flame, always open the valve of the acetylene cylinder 1 to 1.5 turns.
If the valve is opened less than this, the acetylene flow rate may be insufficient and cause flashback when
switching from an air-acetylene flame to a nitrous oxide-acetylene flame.
(5) In the case of nitrous oxide, the flow rate may become unstable if the main valve is not opened enough.
Make sure that main valve is opened enough.
(6) Place all the cylinders upright.
(7) Always leave the cylinder handle attached to the main valve even during use.
(8) After use, not only close the stopcock but also always shut the cylinder main valve.
(9) When the source pressure of the acetylene cylinder decreases to 0.5 MPa, replace the cylinder. In the
case of acetylene gas, a porous mass inside the high-pressure container is soaked with acetone or DMF
(dimethylformamide), and the acetylene gas is dissolved in that by compression. If the internal pressure of
the cylinder decreases to less than 0.5 MPa, vapor of acetone or DMF will become mixed in the acetylene
gas, and the gas flow rate will become unstable. If the internal pressure decreases to less than 0.3 MPa,
the acetone or DMF will flow out, and control of the gas flow rate will be impossible.
CAUTION
1. If the compressor does not work using the above procedure, refer to the instruction manual provided
with the compressor.
2. In order to set the secondary pressure correctly, the secondary pressure must always be lowered to
nearly 0 Pa before turning the control handle <1>.
3. During use, make sure that the oil level always stays between the red lines on the oil gauge.
4. After use, always open the drain cocks and discharge the water and oil inside the tank and the
transformer.
5. If a hand compressor or compressed air pipe is to be used to supply air, verify the following:
a. That air is supplied at a pressure of 0.35 to 0.4 MPa
b. That the pressure does not fluctuate
c. That the air supplied does not contain water, oil, or dust
To Next Page