Taylor-Wharton Bulk Tank Safety Data - Manual (Page 15)

15
Casing Safety Device
When the safety device has ruptured or leakage is caused by corrosion or
other damage, the safety device assembly must be replaced
Warning
Do not start any cutting of welding work until gaseous concentration in the
insulation space has been checked for combustibles. If necessary, purge
insulation space with dry nitrogen gas until combustible gases have been
eliminated. Do not allow pressure in the insulation space to exceed the
pressure in the inner container. External overpressure on the inner con-
tainer could cause permanent damage.
Because re-evacuation is time consuming and usually
requires taking the tank out of service, it is not normally
attempted until tank performance becomes unacceptable.
Even a relatively high degree of deterioration can be
tolerated in a tank from which high rates of withdrawal
are being made. However, if vacuum deterioration
seriously affects tank operation by producing excessive
pressure buildup and high loss rates, re-evacuation may
be warranted.
Note
Do not use Teflon tape as a sealant on vacuum system fittings
When moving a tank from another location after being in cryogenic service,
be sure that the tank is empty and warm. If the tank has been in oxygen or
hydrogen service, purge it warm filtered nitrogen gas to eliminate any
residual combustible gas. To prevent contamination from atmospheric
moisture, pressurize the tank to approximately 20 psig (138 kPa/1.4 bar)
with filtered nitrogen gas and close all valves to retain pressure.
Vertical tanks should be shipped in the horizontal position on wooden
cradles. Shipping drawings may be purchased from the Theodore, Alabama
factory. Give tank model and part numbers when requesting drawings.
Moving the Tank