5
TESTING FOR LEAKS
Every welding and cutting outfit should be thoroughly
tested for leaks after it is first hooked up, and at regular
intervals thereafter. After all connections have been
made, make sure both valves on the torch handle are
closed. Then turn in the regulator pressure-adjusting
screw until the oxygen delivery-pressure gauge regis-
ters 50 psi, the acetylene delivery-pressure gauge
registers 10 psi. Using Leak Test Solution suitable for
oxygen service, such as P/N 998771 (8 oz. container),
check for leaks at the cylinder valves, the cylinder-to-
regulator connections, the regulator-to-hose connec-
tions, and the hose-to-torch connections. If bubbling at
any point indicates leakage, tighten the connection. If
this does not stop the leakage, close the appropriate
cylinder valve, open the torch valve to remove all
pressure from the line, and finally release the regulator
pressure-adjusting screw by turning it counterclock-
wise. Then break the leaky connection, wipe metal
seating surfaces with a clean, dry cloth, and examine
them for nicks and scratches. Remake the connection(s)
and retest. Do not try to light the torch until you are
satisfied that all connections are gas-tight.
After lighting the torch, and adjusting the flames, use
leak test solution to check for leakage at all torch valves,
and at the connection between the torch handle and the
welding head or cutting attachment.
OPERATING PRECAUTIONS
Flow: There must be proper flow of gases for safe
operation and full performance. This requires the fol-
lowing three conditions: (1) the regulators that deter-
mine the inlet pressure to the hoses must be set to the
correct pressure: (2) the hoses and their connectors
must have adequate capacity for the job (hoses that
are too long, too small or have connectors with small
passageways can cause problems); and (3) the throttle
valves on the torch must be adjusted with the proce-
dure shown in these instructions.
Note: Items (1) and (2) can be checked by measuring
the gas pressures
at the torch. Gauge adaptors
are available for this purpose.
Backfire: Improper operation of the torch may cause
the flame to go out with a loud ‘pop’. Such a backfire
may be caused by contact of the tip with the work,
spatter from the tip, or by attempting to operate with too
small a flame. After a backfire, you can normally relight
the flame immediately. If backfires occur repeatedly,
shut off the torch. Then reopen the oxygen valve,
check for correct oxygen pressure, and test for leak-
age at the welding head connection nut and tip connec-
tion nut. If there is leakage at either point, correct it (by
tightening the tip, or cleaning the seating surfaces on
the injector and in the torch body) before resuming
work.
Flashback: Under certain circumstances, the flame
may not ‘pop’ out (backfire) but instead burn back inside
the torch with a shrill hissing or squeal. This is called a
‘flashback’. A flashback should never occur if (1) the
equipment is in good condition; (2) preheat ports on
cutting nozzles or welding tips are cleaned frequently;
(3) operating pressures are correct; and (4) throttle
valves are adjusted properly. Should a flashback occur,
IMMEDIATELY shut off the torch. Allow it to cool off for
at least a minute. Then check your nozzle or tip, gas
pressure, readjust regulators if necessary, and relight
the torch. If flashback recurs, send the torch handle and
welding head or cutting attachment to ESAB
Remanufacturing Center or to your distributor for re-
pair.
To Next Page
Loading...