Specifications
15
TROUBLESHOOTING
56
Problem Problem Cause Corrective Action
Liquid cylinder builds
excessive pressure or
b
uilds pressure too fast.
Liquid cylinder pressure
is too low.
Frost occurs around the
circumference of the
shell 4" to 8" (10.2 to
20.4 cm) from the floor.
Frost occurs around the
circumference of the
shell 10" (25.4 cm)from
the floor and up. Frost
spot spirals up the shell.
Low usage.
Cylinder is over filled.
Pressure building regulator
is set improperly or leaks.
Vacuum is deteriorating.
Pressure builder valve is
closed.
Pressure building regulator
is set too low.
Pressure building regulator
is not opening properly.
Usage is too high.
Cylinder is leaking.
Cylinder is building
pressure with the
pressure building circuit.
Frost is residual from last
fill or earlier use.
Cylinder is vaporizing
liquid into gas.
If daily gas usage is under 100 SCF (2.8 NM
3
), the
c
ylinder will build pressure. In liquid service, the cylin-
der should be equipped with low pressure relief valve
and regulator. Normal pressure rise should not be
more than 50 psi (3.4 BAR)per day.
If the cylinder is filled past the vent trycock or past the
DOT specified fill weight, the pressure may rise rapidly
after a fill.
If the pressure builds and stays at a pressure higher
than desired, adjust the pressure building regulator to
a new setting
If the pressure builds to the relief valve setting and the
P. B. coil near the bottom of the tank is cold or frosted,
replace the regulator.
This can be accompanied by cold or frost occurring
evenly over the cylinder surface. Refer to the trouble-
shooting section on frost.
Open Valve.
Adjust the regulator as described in Section 16,
page 60 (For gas service)
Bench test the regulator for full flow at the set pressure
as described in Section 16, page 62.
Refer to Section 6, pages 14-16 (Specification), for
maximum recommended delivery rates; or to Figure H,
page 12 for pressure building capacities.
Check for frost on lines or on top of head. Listen for
hissing, soap test joints for leaks. Isolate leak and call
Chart for repair details.
This is normal if the cylinder pressure is lower than
the pressure building regulator setting.
This is normal. A ring of ice or an oval shaped ice ball
often remains on the cylinder for days after the last
use or fill.
This is normal. The frost should melt within two hours
after the gas use stops
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