Taylor-Wharton Microbulk Tanks - Manual (Page 22)

TW-407 Rev.-
20
8 To reset the regulator, loosen the lock nut on the adjusting screw. Raise the set point by turning the
adjusting screw clockwise; lower the set point by turning the screw counterclockwise. After adjust-
ment, repeat steps 5 and 6 to check the setting before reinstalling the regulator on the liquid container.
9 When reinstalling the pressure-building regulators on the system, orient the regulator so the flow
arrow points away from the pressure-building valve.
Adjustment of the economizer regulator should be accomplished with the regulator removed from the
system. The regulator bench adjustment fixture should be used.
1 Leak test joints between the high pressure cylinder regulator and the dump valve. Joints must be leak
free before proceeding.
2 Close the on/off valve. Open the dump valve.
3 Open the high-pressure cylinder valve.
4 Set the high-pressure regulator above the desired set point for the economizer.
5 Slowly open the on/off valve for a few seconds and then close it.
6 When the regulator has been adjusted, the economizer set point is indicated on the upstream pres-
sure gauge.
7 To reset the regulator, loosen the lock nut on the adjusting screw. Raise the set point by turning the
adjusting screw clockwise; lower the set point by turning the screw counterclockwise. After adjust-
ment, repeat steps 5 and 6 to check the setting before reinstalling the regulator on the liquid container.
8 The economizer regulator should be reinstalled oriented horizontally with the tube compression fit-
ting threaded into the side port.
User adjustment of the pressure gauge or liquid-level gauge is not possible. If the gauges are malfunc-
tioning, they must be replaced. Close both isolation valves (V-8 and V-10) and immediately open the
equalization valve (V-9). Loosen one of the tube compression fitting nuts to reduce pressure. When
the pressure gauge (PI-1) indicates zero it is safe to work on the circuit.
Cryogenic containers are two containers, one within the other. The space between the containers acts
as a highly efficient thermal barrier including high technology insulation, a vacuum, and a vacuum-main-
tenance system. Each serves a very important part in the useful life of the container. The high technol-
ogy insulation is very effective in preventing radiated heat from entering the inner container. Unfor-
tunately, the perfect vacuum cannot be achieved since trace gas molecules begin to enter the vacuum
space from the moment of manufacture. The vacuum-maintenance system consists of materials that
gather trace gas molecules from the vacuum space. The maintenance system can perform its function
for years; however it has a limited capacity. When the vacuum-maintenance system becomes saturated
it can no longer maintain the vacuum integrity of the container. The change will be very gradual and
may go unnoticed for several years. When the vacuum in the insulation space is no longer effective, the
following symptoms may appear:
Instruments
Vacuum
MAINTENANCE