Taylor-Wharton Auto Fill Laser Pak - Manual (Page 4)

4
INTRODUCTION
This manual provides information for the operation and maintenance of Taylor-Wharton's Auto-Fill Laser Pak
cryogenic liquid pressurization system. The Auto-Fill Laser Pak is intended for use in applications requiring
nitrogen or argon at pressures higher than possible from standard 175 or 250 psig cryogenic bulk tanks.
Cryogenic liquid is supplied to the Auto-Fill Laser Pak from a standard bulk tank. The Auto-Fill Laser Pak
“boosts” the liquid up to pressures as high as 450 psig. Once the pressure of the cryogenic fluid is raised to the
desired level, the Auto-Fill Laser Pak is capable of delivering liquid to a downstream vaporizer at gas
equivalent rates as high as 15,000 standard cubic feet per hour. The supply of product out of the Auto-Fill
Laser Pak is continuous even when the bulk tank is being filled.
Product specifications, flow diagram, views, and important dimensions are shown on the general arrangement
drawing, AF55-0C00_GA, provided in this manual.
System Description
The Auto-Fill Laser Pak consists of three groups of components: vessels, piping circuits, and
control/instrumentation. These components are assembled to a stainless steel frame for easy installation.
Two 196-liter vessels are included in the system. Each vessel consists of a pressure vessel suspended inside a
jacket. The space between the pressure vessel and the jacket is evacuated and insulated with a micro-
fiberglass / aluminum foil radiation shield. The pressure vessel is designed and constructed in accordance
with the ASME Boiler and Pressure Vessel Code Section VIII, Division 1. Both the inner pressure vessel and
vacuum jacket are constructed of type 304 stainless steel.
The piping circuits allow the vessels to vent, fill, pressurize, and deliver cryogenic liquid to the vaporizer.
Eight solenoid valves, four for each vessel, control flow. Two high capacity pressure builders, one for each
vessel, use heat from ambient air to maintain pressure in the vessels. Piping is type-304 stainless steel. Valves
are brass. Weld and compression type fittings are type-316 stainless steel. Compression fittings are double
ferrule type. Screwed fittings are machined from forged brass. The pressure builders are constructed of
aluminum.
The controller is housed inside a NEMA 4X fiberglass enclosure. Instrumentation consists of two differential
pressure transmitters and three pressure transmitters. A differential pressure transmitter is piped to each of the
vessels in order to measure liquid level. Gauge pressure transmitters monitor pressure in each of the vessels
and the bulk tank. The bulk tank pressure transmitter is provided with the system. All wiring is in accordance
with the National Electrical Code.
The Auto-Fill Laser Pak pressurizes cryogenic liquid by adding heat to the liquid in a controlled fashion. All
energy for building pressure is provided by heat from ambient air. Electrical power is required only to operate
the controller, instruments, and solenoid valves.
Operation Sequence: Brief Overview
Consider the following starting conditions: vessel A is empty of liquid and filled with high-pressure gas;
vessel B is filled with liquid and pressurized. (See piping schematic on page 6.)
1.
Liquid from vessel B is supplied at pressure to the vaporizer. Vessel B is in SUPPLY mode.
2.
High-pressure gas from vessel A is vented back to the bulk tank. Vessel A is in VENTING TO
BULK mode. This feature minimizes product loss during filling.