Taylor-Wharton EF-1500 - Manual (Page 23)

BT-481 REV. B
23
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 under adjustment closes, the economizer set point is indicated on the upstream pressure
gauge.
7.
To reset the regulator, loosen the lock nut on the adjusting screw. Raise the setpoint by turning the
adjusting screw clockwise; lower the setpoint by turning the screw counterclockwise. After adjustment,
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 fitting
threaded into the side port.
Instruments
User adjustment of the pressure gauge or liquid level gauge is not possible. If the gauges are malfunctioning, 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.
Vacuum
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 maintenance system. Each serves a very
important part in the useful life of the container. The high technology insulation is very effective in preventing radiated
heat from entering the inner container. Unfortunately, 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:
1.
With liquid in the container, the outer casing will be much colder than comparative containers.
2.
Frost, indicating the liquid level, may be visible on the outer casing of the container.
3.
Condensation may form on the container. Note that some icing or condensation is normal around the
piping connections of the vessel. Condensation may also occur on the vessel outer surface as a result of
high humidity.
4.
The relief valve will open continuously until the container is empty.
If it has been determined that the vessel has a vacuum problem it will be necessary to repair and re-evacuate the vessel. A
skilled service technician should perform vessel repair. Contact Taylor-Wharton customer service at 1-800-898-2657 for
assistance in locating the closest service center.