Taylor-Wharton High Capacity GST Storage Tanks - Manual (Page 7)

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INTRODUCTION
This manual provides information for the user to operate and maintain Taylor-Wharton's GST-250
model cryogenic storage tanks which can be supplied with Taylor-Wharton Final Piping or
customer specific Final Piping Options. These tanks are suitable for the storage and delivery of
liquid oxygen, nitrogen or argon at a maximum allowable working pressure of 250 psig (17.24
bar/1724 kPa). They are also suitable for the delivery of gaseous product when combined with a
vaporizer.
Tank specifications, flow diagram and an elevation with bottom view of the tank showing controls
and piping may be found on the General Arrangement Drawings located in the back of this manual.
Additional copies of these drawings may be obtained from the factory. Please include information
on the tank model number and part number in making drawing requests. Tank Specifications,
Rigging Details and Vacuum System Components are also shown in this manual.
FUNCTIONAL DESCRIPTION
TANK CONSTRUCTION
The GST-250 tanks are vertical tanks with a maximum allowable working pressure of 250 psig
(17.24 bar/1724 kPa). The pressure vessel is suspended inside a vacuum jacket and insulated with
perlite powder under high vacuum. The liquid and gas phase lines to the pressure vessel pass
through the lower head of the vacuum jacket. All piping is designed to withstand the stresses
caused by expansion and contraction of the pressure vessel, its support system and piping itself.
The pressure vessel is designed and constructed in accordance with the ASME Boiler and Pressure
Vessel Code Section VIII, Division 1. The inner vessel is constructed of 304 stainless steel and the
piping is stainless steel. The vacuum jacket and leg supports are made of structural steel.
The insulation space between the pressure vessel and the vacuum jacket is filled with perlite
powder insulation and evacuated to a high vacuum through a VACUUM PUMPOUT VALVE that
is permanently sealed at the factory. Insulation space vacuum is measured in the field by
connecting a vacuum gauge to the VACUUM PROBE, which is located on the lower head of the
tank. The VACUUM PROBE is isolated from the vacuum jacket by a VACUUM PROBE
ISOLATION VALVE.
PIPING
The following paragraphs describe the operation of the main circuits of the GST-250 bulk tanks.
The descriptions refer to the main components of each circuit and are grouped by function. These
component and circuit descriptions are pertinent to any of the GST-250 tanks and should be read
before attempting operation.