CHART LH2 ST18600 User manual

Product Manual
LH2 ST18600 Transport Trailer
Designed and Built by:
Chart Inc.
4075 Hamilton Blvd.
Theodore, AL 36582 USA
[phone]
Part Number 22034324 Rev. B
© 2023 Chart Inc.

Product Manual - Liquid Hydrogen Trailer Series
III
Contents
Revision Log
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV
.1
General
1
Reporting Safety
Defects
1
Non
-
disclosure
Agreement
1
Terms
2
Acronyms / Abbreviations 2
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Safety
Summary
3
General LH2 Safety 3
Vessel
Safety
4
Intended
Use
4
Trailer
Line
Safeties
4
Damaged
Vessels
4
Design
Modification
5
Operator
Qualifications
5
Manufacturer Liability
Statement
5
Introduction
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.6
General
Precautions
6
Terminology
of
Cryogenics
6
States
of
Matter
6
Saturation
6
Equilibrium
6
Saturation
Pressure
6
Vaporization
6
Vapor
Pressure
6
Entrainment
6
Liquid
Growth
6
Pressure
Drop
7
Stratification 7
Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Setup and Preparation of Equipment for Use 8
Operating
Instructions
8
Cooldown and
Purge
8
Sweep and Pressure
Purge
10
Normal
Trailer
Fill
10
Filling
by
Weight
11
Customer
Fill
11
Abnormal
Situations
14
Reading
Tank
Pressure
14
Reading Liquid
Level
15
Taking
a
Liquid
Sample
15
Lifting
Trailer
Empty
15
Moveable Kingpin
Plate
15
Safety Relief Valve Removal 15 Inner
Vessel Repairs 15 Suspension Air
Bag Dump Valve 16 Flowmeter Operation
16
Troubleshooting ........................................................................................................................................... 17
Suggested Preventative Maintenance Schedule 19
Wear
Appropriate
Clothing
and
Protective
Gear
3
Keep
Away
from
Flame
or
Spark
3
Remove
Excess
Pressure
and
Liquid
4

IV
Product Manual - Liquid Hydrogen Trailer Series
Maintenance & Repair ................................................................................................................................ 20
Inspection
20
Lubrication
20
Running
Gear
20
Vacuum
20
Soap
Testing
the
Outer
Shell
21
Valves
and
Safety
Devices
21
Shut
Off
Valves
21
Insulation
21
Gauges
21
Electrical
System
22
Emergency Shutoff and Hose Interlock/Anti-Tow Pneumatic System 22
Preventive Maintenance Log 23
Specifications ................................................................................................................................................ 24
Revision Log
Revision Level Date Description
A 12/6/2022 New Manual Creation
B 04/28/2023 Content Update

Product Manual - Liquid Hydrogen Trailer Series
Preface 1
Preface
General
This manual is an important reference tool - keep it with
the trailer at all times. The purpose of this manual is to
provide owners, operators, and service technicians with the
precautions and operating procedures essential for the safe
and proper trailer operation.
All information in this manual should be read and
understood before any attempt is made to operate the trailer.
This manual is a supplement to and not a replacement
for your organization’s internal safety procedures. Always
follow organizational policies and procedures. Proper
safety practices are the responsibility of the owners, users,
operators, and service technicians.
All instructions in this manual are based upon the use of the
trailer under proper operating conditions, with no deviations
from the original design. Any alteration or modification of
the trailer is strictly forbidden without written approval from
Chart Inc.
Reporting Safety Defects
If you believe that your vehicle has a defect which
could cause a crash or could cause injury or death, you
should immediately inform the National Highway Safety
Administration (NHTSA) in addition to notifying Chart Inc.
If NHTSA receives similar complaints, it may open an
investigation, and if it finds that a safety defect exists in a
group of vehicles, it may order a recall and remedy campaign.
However, NHTSA cannot become involved in individual
problems between you, your dealer, or Chart Inc.
To contact NHTSA, you may call the Vehicle Safety Hotline
toll-free at 1-888-327-4236 (TTY: 1-800- 424-9153); go to
http://nhtsa.safercar.gov; or write to: Administrator, NHTSA,
12000 New-Jersey Avenue SE, Washington, DC 20590. You
can also obtain other information about motor vehicle safety
from http://www.safercar.gov.
Non-disclosure Agreement
The design of this trailer and contents of this manual
are the intellectual property of Chart Inc. and protected
by various non-disclosure agreements between Chart,
customers, and subsidiaries of both companies. Disclosure
of any information contained herein is expressly prohibited
subject to the terms and conditions of the non-disclosure
agreements. Individual employees may be held personally
liable for such prohibited disclosures.

2
Preface Product Manual - Liquid Hydrogen Trailer Series
Acronyms / Abbreviations
The following acronyms / abbreviations are used throughout
this manual:
ASME American Society of Mechanical Engineers
BAR Metric Unit of Pressure
BARG Metric Unit of Gauge Pressure
CGA Compressed Gas Association
CP Connection Point
DOT Department of Transportation
GPM Gallons Per Minute
HV Hand-operated Valve
LH2 Liquid Hydrogen
LI Level Indicator
LN2/LIN Liquid Nitrogen
LOX Liquid Oxygen
LPM Liters Per Minute
MAWP Maximum Allowable Working Pressure
NER Normal Evaporation Rate
NIST National Institute of Standards and Tech
NPSH Net Positive Suction Head
OEM Original Equipment Manufacturer
PB Pressure Builder
PCV Pressure Control Valve
PI Pressure Indicator
PN Part Number
PSI Pounds per Square Inch
PSIA Pounds per Square Inch Absolute
PSIG Pounds per Square Inch Gauge
PSID Pounds per Square Inch Differential
PTO Power Take-Off
P&ID Piping & Instrumentation Diagram
RV Relief Valve
RTD Resistance Temperature Device
SS Stainless Steel
UT Ultrasonic Testing
UV Ultra-compact Valve (Pneumatic-Actuated)
VAC Voltage - Alternating Current
VDC Voltage - Direct Current
VFD Variable Frequency Drive
VJ Vacuum Jacket
Terms
Throughout this manual safety precautions will be designated
as follows:
Warning! Description of a condition that
can result in personal injury or
death.
Caution! Description of a condition that
can result in equipment or
component damage.
Note: A statement that contains information
that is important enough to emphasize or
repeat.

Product Manual - Liquid Hydrogen Trailer Series Safety
3
Safety
Safety Summary
Although safety features have been installed to aid in safe
operation and maintenance of this system, it is essential
that all personnel having contact with this equipment
become thoroughly familiar with all safety precautions and
procedures contained in this manual. Personnel operating
LH2 (Liquefied Hydrogen) systems should review all laws,
rules and regulations pertaining to the use of LH2. Personnel
must also be knowledgeable of the properties of LH2 and the
safety equipment required for handling LH2.
The safety of personnel and equipment is the responsibility
of the customer. The instructions and guidelines provided
within this manual are only recommendations. Personnel
should refer to the safety procedures and policies of their
company.
General LH2 Safety
It is recommended that all personnel involved with the
handling of LH2 should be familiar with the characteristics
of both the liquid and the gas produced. The potential
hazards in handling LH2 stem mainly from three important
properties:
• LH2 is an Extremely Cold Liquid – At atmospheric
pressure, depending upon composition, LH2 boils at about
-252°C.
• A Small Quantity of Liquid Converts into a Large
Volume of Gas – One volume of LH2 produces
approximately 845 volumes of gas.
• Flammability– Hydrogen is extremely flammable. At
ambient conditions the flammable mixture range with air
is from 4% to 75% gas by volume.
Hydrogen, Refrigerated Liquid
DOT UN Number UN1966
Transport Hazard Class 2.1
Label Flammable Gas
This equipment contains pressurized LH2 at cryogenic
temperatures. The major components in the system generally
Warning! NEVER use components
(valves, gauges, fittings,
etc.) or piping as steps
or footholds. Always use
appropriate equipment to
access components for
maintenance or repair.
Wear Appropriate Clothing and Protective
Gear
Accidental contact of LH2 with skin or eyes may cause a
freezing injury similar to a burn. Personnel must wear the
appropriate clothing and protective gear while working
around the equipment, especially when making or breaking
connections. Do not allow liquid to splash, spill or leak.
Protect eyes and cover skin wherever the possibility of
contact with liquid, cold equipment or cold gas exists. Use
clean, easily removable insulated gloves and long sleeves
for arm protection. Cuff-less trousers should be worn over
the shoes to allow spilled liquid to be shed away from the
Operator’s body.
Wear the following items whenever working on this
equipment:
• Safety Glasses
• Clean Insulated Gloves
• Long-sleeved Shirt
• Cuff-less Trousers
• Appropriate Shoes
• Harnesses and Retrieval Lines (if entering confined
spaces)
• Flame Resistant Clothing
• Face Shield
• Apron
Keep Away from Flame or Spark
Hydrogen is flammable. All general-purpose electrical
equipment (e.g, cellular phones, etc.) is prohibited in areas
consist of pressure-containing components (such as a vessel
and pipes) encased within outer steel vacuum shells. The where LH2 is stored or handled. LH2 must be stored and
pressure vessel operates under medium pressure at
extremely low temperatures. Personnel operating this
equipment must always adhere to the safety precautions
included in the section.
transferred under positive pressure to prevent the infiltration
of air or other gases. Keep LH2 equipment away from open
flames or electrical sparks. Never permit smoking in areas
where LH2 equipment is repaired, used or stored.

4
Safety Product Manual - Liquid Hydrogen Trailer Series
Warning! Due to the flammable
properties and the risk of
asphyxiation, LH2 must never
be stored in confined areas
or areas unsuitable for LH2
storage. Always exercise
caution when storing LH2
containers or parking LH2
vehicles.
Remove Excess Pressure and Liquid
This equipment is a pressurized system. LH2 will boil and
build up pressure in the system. Isolate the affected section
and empty the section of liquid before removing parts or
loosening fittings. Always remove parts and fittings in a safe
manner. Working on a pressurized section in an unsafe or
careless manner can cause serious injuries, or even death.
External valves and fittings can become extremely cold and
can cause painful burns to personnel who are not adequately
protected. Always empty LH2 and remove pressure from the
system before removing any parts or components.
Caution! DO NOT trap LH2 between
two shutoff valves without a
relief device to protect piping.
Trapped LH2 can vaporize and
rapidly increase pressure,
causing pipes to burst.
Vessel Safety
Intended Use
This LH2 transport trailer is designed for transportation
and delivery of liquid hydrogen, along with incidental
storage. The trailer is filled with liquid hydrogen at a fill
plant, transported to one or more delivery sites, and liquid
hydrogen is delivered by pressure transfer, with pressure built
and maintained at a safe-level by the on-board vaporizer
(pressure building coil). This trailer should never be used
to transport liquid hydrogen at a pressure in excess of
DOT regulations nor to build pressure above its MAWP.
Further, the trailer is intended for operation only by trained
professionals and in accordance with CFR. While the liquid
hydrogen transport trailer may be used for occasional
or incidental storage of product, please note the NER
and corresponding boil-off and pressure rise rates when
determining the feasibility of storage and associated impact
on product delivery (including loss of deliverable product).
This trailer must not be used for any purpose other than
described herein due to the risk of injury (including fatal
injuries) or property damage to the trailer and any nearby
equipment. Neither the manufacturer nor their associated
firms or employees can be liable for any damages resulting
from improper utilization of this liquid hydrogen transport
trailer.
Tank Safety Components
Note: The tank safety components in the
following illustrations are denoted with
purple boxes.
Trailer Line Safeties
Multiple line safeties are installed on the Trailer.
• Trailer Line Safeties will open to vent if the
pressure in the adjacent line exceeds 225 psig.
Damaged Vessels
Cryogenic vessels are at times exposed to unforeseen
catastrophic environmental and ecological conditions. Extra
caution must always be taken whenever a cryogenic vessel is
involved in an incident compromising the vessel or its safety
devices. Always exercise extreme caution whenever a vessel
has been exposed to extreme heat, fire, or exposed to adverse
weather and ecological conditions (earthquakes, tornadoes,
hurricanes, etc.).
Always exercise extra caution if a vessel is suspected of
abnormal operation. In the case of known or suspected vessel
vacuum problems (even if extraordinary circumstances such
as those noted above have not occurred), do not continue
to use the unit. Continued use of a cryogenic vessel that
has a vacuum problem can lead to more severe conditions,
including the vessel becoming brittle and cracking. The outer
steel jacket may rupture due to inordinate stress conditions
caused by an internal liquid leak.
Carefully empty contents from a damaged or suspect vessel
as soon as possible. Never, under any circumstances, leave
product in a damaged vessel for an extended period. Do not
refill a damaged vessel until it is repaired and re-certified. It is
strongly recommended that damaged vessels be evaluated by
trained Chart technicians prior to returning the vessel
into service.

Product Manual - Liquid Hydrogen Trailer Series Safety
5
Design Modification
• DO NOT use this trailer in a manner inconsistent with
the instructions outlined in this manual.
• DO NOT alter the trailer design or perform any service
inconsistent with the instructions outlined in this manual
without the prior written approval of Chart Inc.
• ALWAYS use replacement parts authorized by Chart Inc.
when replacing parts and components.
Operator Qualifications
Chart hydrogen trailers are designed for safe and simple
operation. Operators are expected to be knowledgeable
regarding the nature of the gas(es) with which they are
working, as well as all applicable safety requirements. This
manual contains several sections dealing with operating
instructions, handling instructions and maintenance
procedures. To fully understand these procedures, we
recommend that Operators and Maintenance Personnel first
become familiar with the system controls and indicators.
Manufacturer Liability Statement
The manufacturer believes the information presented in
this manual to be accurate and up to date and assumes no
liability concerning use of information contained herein
by any party. The information contained herein is not a
recommendation to violate federal, provincial, state, or
municipal laws or regulations.

6
Introduction Product Manual - Liquid Hydrogen Trailer Series
Introduction
General Precautions
Cryogenic liquids, even in large quantities can be safely
transported, handled and stored. Safe handling practices
are based on an understanding of the specific properties of
the cryogenic liquid to be handled and knowing the liquid’s
material compatibility. The Compressed Gas Association
(CGA) Publication, P-12 - Safe Handling of Cryogenic
Liquids, provides recommended procedures for the handling
of the most common cryogenic liquids.
Cryogenic liquids are extremely cold. Cryogenic liquids have
a normal boiling point below -130°F according to National
Institute of Standards and Technology (NIST) Handbook 44,
Specifications, Tolerances, and Other Technical Requirements
for Weighing and Measuring Devices. The cryogenic liquids
and their cold boil-off vapors can rapidly cause frostbite. The
cold piping in the rear compartment or pressure building coil
on a liquid hydrogen trailer can reach below the boiling point
of liquefied air, -318°F, and can condense the surrounding
air into liquid. This liquid air can quickly create an oxygen
rich environment and the safety precautions for such an
environment must be followed. Liquid Hydrogen is also
flammable and should be handled accordingly.
Personal Protective Equipment is required to operate
this trailer. Safety glasses with side shields, along with a
hardhat and face-shield should always be worn. Insulated
gloves when handling anything that comes in contact with
cryogenic liquids and vapors. Gloves should be kept free
of oil and grease and if contaminated, should be discarded.
Appropriate flame-resistant clothing shall be worn that meets
the standards of NFPA 2112, Standard on Flame-Resistant
Garments for Protection of Industrial Personnel Against
Flash Fire.
Terminology of Cryogenics
States of Matter
Matter can exist as a gas, liquid, or a solid. Two phase liquid
is a liquid with gas bubbles or slugs of gas due to lack of
pressure (subcool) to maintain equilibrium. Gas and liquid
can exist at a range of temperatures.
Saturation
Defined as the point at which liquid and vapor coexist at the
same pressure and temperature.
Liquid density, temperature, and equilibrium pressure change
with the saturation condition of the liquid. Saturation can
also be described as an energy state. Liquid molecules at a
higher energy state (warmer) take up more space, which is
often referred to as liquid growth.
Equilibrium
In a closed vessel the gas and liquid temperatures are the
same. If there is a temperature difference between the gas and
liquid (with the tank closed), the gas and liquid will change
their temperatures until they are equal. In stationary tanks,
stratification can take place, creating a temperature gradient
across the liquid and vapor. However, the temperature at the
liquid-vapor interface is the same for both.
Saturation Pressure
Pressure (usually in psig) that is used to describe the current
saturation condition of a liquid and gas within a closed
container.
Vaporization
Changing liquid into vapor by warming the liquid for the
purpose of subcooling or for gas use.
Vapor Pressure
Pressure of the vapor space within a tank. Measured by
reading the tank pressure gauge, if at equilibrium..
Entrainment
Liquid carried along with venting gas. This can occur during
violent depressurization of a tank and during the top filling
of a tank with the vent valve open. Large product losses will
occur during this event.
Liquid Growth
As liquid warms to higher saturation pressures, the volume
increases. Warm liquid is less dense. Less dense liquid takes
up more volume. Liquid growth is a safety concern if the
liquid is allowed to grow until it fills the storage vessel. This
condition is called liquid full or hydraulically full. During this
condition the pressure rises rapidly, the safeties will relieve,
and the tank will vent liquid.

Product Manual - Liquid Hydrogen Trailer Series Introduction
7
Pressure Drop
Pressure lost due to the flow of liquid. The faster liquid flows
through the piping circuit, the higher the pressure drop.
Stratification
Warm liquid is less dense. This less dense liquid will find its
way to the top of the tank. Colder more dense liquid will
remain at the bottom. The layering of temperature zones
from top to bottom is called stratification.

8 Operations
Product Manual - Liquid Hydrogen Trailer Series
Operations
Setup and Preparation of Equipment
for Use
This trailer was shipped from Chart Inc. cleaned, tested,
purged with nitrogen, and, in the case of some units, filled
with and in hydrogen service. All lubrication points were
fully serviced.
1. Upon receipt at the site, the trailer should be examined
for broken or damaged lights, gauges, tubing, pneumatic
and electric conduit, piping, cracked joints, and valves.
Look particularly for broken glass, bent pointers and
bent valve stems.
2. Inspect all equipment for the presence of grease, oil, or
organic matter that might come in contact with liquid
or gaseous hydrogen. Remove any such foreign matter
completely.
3. Check vacuum to be sure that it has not been lost during
shipment.
Operating Instructions
See Piping Schematic in the Trailer Dossier.
Before operating the trailer, become familiar with the safety
precautions described in Section 1.1 of this manual. Study
the figures, particularly the P&ID and the rear compartment
piping diagrams which are included in the appendices. Also
study the descriptions of the equipment contained in Section
1.2.
Thoroughly read and understand the instructions in this
manual BEFORE operating the equipment. Direct any
questions about this system to your supervisory personnel.
Untrained personnel should NOT be permitted to operate
any equipment.
When performing any operation on equipment that has not
been purged with nitrogen gas, connect a grounding cable to
the trailer chassis.
When filling the trailer with liquefied hydrogen for the first
time or refilling it after it has been out of service, the trailer
must be purged and precooled generally as follows:
4. Dry the inner container with warm air or nitrogen gas
5. Nitrogen gas purge
6. Liquid nitrogen precool/purge
7. Cooldown
8. Purge/leak check
9. Evacuation or sweep purge with cold hydrogen gas
10. Pressure purge
The detailed procedures for purging and precooling
are contained in this chapter, as well as the procedures
for loading and unloading the trailer. Other operating
procedures are contained in subsequent sections of
this manual.
When discharging hydrogen or nitrogen gas to the
atmosphere, observe the safety precautions for handling
liquefied hydrogen and nitrogen.
Caution! If a warm tank is filled before
pre-cooling structural damage
may result.
Cooldown and Purge
11. Position the tractor and trailer so the transfer hoses
can reach the connections without sharp bends. Set the
brakes and place the wheel chocks in position.
12. Connect the grounding cable to the trailer chassis.
13. Close all trailer valves and cap all connections (refer to
the labeled photograph of the rear compartment, Trailer
Dossier) except liquid phase (fill and withdrawal) and
gas phase hose connections.
14. Remove protective cap from transfer hose. Connect
transfer hose cold nitrogen gas source to the gas phase
connection (C2). In order to connect transfer hose to
the gas phase connection (C2), the anti-towaway flag
system will have to be lowered. This will lock the brakes.
15. Open valve (HV11) and admit cold nitrogen gas to
inner container.
16. Apply tractor air pressure to the green gladhand or
auxiliary air pressure through customer air connection
(CP1) and set the four remote emergency shutoff valves
(HV105A,B,C,D) to the “open” position to open valves
(UV9) and (UV10).
17. Open valve (HV9) and discharge nitrogen gas through
the liquid phase connection (C1).
18. Continue gas flow until the exiting gas temperature is
below -200º F. Close valve (HV9).

Product Manual - Liquid Hydrogen Trailer Series
Operations 9
19. Close valve (HV11), open valve (HV71), disconnect
transfer hose and replace protective cap on gas transfer
hose.
20. Remove protective cap from liquid transfer hose and
connect the hose from a liquid nitrogen source to the
liquid phase connection (C1).
Caution! If your trailer is equipped with
HQK fittings, do NOT use tools
on the handwheel of the “V”
band clamp. These fittings
should be HAND TIGHTENED
ONLY.
21. Open valve (HV9M) and slowly charge the container
with 100,000 cubic feet (NTP) of liquid nitrogen
(approximately 931gallons). Make sure container
pressure does not exceed 20 psig during cooldown.
Warning: Trailer must not be moved
containing any amount of liquid
nitrogen due to risk of damage
to load rods and baffle.
Caution! The liquid level gauge and
liquid level chart are intended
for liquid hydrogen and will
not be a reliable method for
determining the amount of
liquid nitrogen inside the trailer.
22. Close valve (HV71), open valve (HV11) to discharge
nitrogen gas through the gas phase connection. Open
valves (HV22A) and (HV7B) to rear pressure gauge.
Maintain inner container pressure at 25 psig for purging.
23. Close valves (HV9) and (HV11). Open valve (HV12).
Crack open valve (HV88) one quarter turn and valve
(HV71) for 30 seconds, then close. Throttle or close
valve (HV12) and/or throttle valve (HV11) to maintain
container pressure at 25 psig.
24. Close valves (HV21B) and (HV22B), then disconnect
the two tubing fittings at the liquid level gauge (LI19).
Open valves(HV21A) and (HV21B) and discharge
nitrogen gas through the fitting for ten seconds. Close
valve (HV21B) and reconnect the fitting. Repeat this
procedure for valve (HV22B).
25. Loosen the fitting at each pressure gauge (PI20A/PI20B).
Open valves (HV10), (HV21B), (HV23) and (HV7B)
(at rear gauge) and purge for 10 seconds. Close valve
(HV7B). Open valves (HV22B) and (HV7A) and purge
for 30 seconds. Close valve (HV7A). Reconnect tubing
fittings.
26. Open valves(HV34) and (HV35) and purge for 10
seconds. Close valves(HV34) and (HV35).
27. Open valves (HV10), (HV21B), (HV22B),, (HV23),
(HV7A) and (HV7B).
28. Open valve (HV91), disconnect transfer hose from
liquid phase connection (C1). Replace protective caps
on hose and pressure caps on the liquid and gas phase
hose connection.
29. The trailer may be left unattended during the cooldown
by opening valve (HV14A). Road relief valve (PCV15)
will relieve container pressure when it exceeds 17 psig.
30. During cooldown, reduce container pressure to 1
psig by opening blowdown valve (HV12).
Note: For maximum cooldown, keep liquid
nitrogen in the trailer for 72 to 96 hours.
A shorter nitrogen cooldown will produce
higher hydrogen cooldown losses
31. Close all valves except (HV21A), (HV22A), (HV21B),
(HV22B), (HV7A), and (HV7B).
32. Open valve (HV42). Apply tractor air pressure or
auxiliary air pressure through customer air connection
(CP1) and set the four remote emergency shutoff
valves to the “open” position to open valves (UV9) and
(UV10).
33. Throttle valve (HV10) to maintain container pressure
between 5 psig (minimum) and 100 psig (maximum).
34. Open valve (HV76) and remove pressure cap from the
gas phase connection. Open valve (HV11) and discharge
gas for 10 seconds. Close valve (HV11) and replace cap
immediately. Open valve (HV11) and discharge nitrogen
gas through valve (HV76) for 10 seconds. Close
valves(HV76) and (HV11).
35. Remove cap from sample valve (HV34) connection
(C30), open valve (HV34) and purge for 10 seconds.
Close valve (HV34). Replace cap (C30).
36. Remove pressure cap from the liquid phase connection.
Open valve (HV9) and discharge nitrogen gas for
10 seconds. Close valve (HV9) and replace cap
immediately. Open valve (HV9) and (HV71). Purge for
10 seconds, then close valve (HV71).
37. Open (HV70A or HV70B) from isolated outlet of
valve (HV59). Switch valve (HV59) and purge for 10
seconds. Switch valve (HV59) back and close (HV70A
or HV70B). Switch valve (HV59) again and repeat the
procedure on the other side after opening (HV70A or
HV70B).
38. Using the pressure building coil, increase container
pressure to 140 psig. Open valves (HV9), (HV42),
(HV11), (HV21A), (HV21B) and (HV7A/7B). Exercise
valve (HV59) at least three times during the leak check.

10
Operations Product Manual - Liquid Hydrogen Trailer Series
39. Check all connections, joints, safety devices, valves and
gauges for leakage. Check both outlet circuits of valve
(HV59). Repair all leaks immediately.
40. When cooldown, purging and leak testing of the
external piping are completed, drain the residual liquid
nitrogen from the container. Allow the trailer to remain
in a closed condition for 2 hours, then proceed.
Sweep and Pressure Purge
41. Complete the cooldown, purge and leak test procedure
per Section 2.2.1. Trailer and vent stack grounding
cables must be connected. Open valves (UV9) and
(UV10). Valves HV105A, HV105B, HV105C, and
HV105D must be in the “open” position and a minimum
of 30 psig air pressure is required.
42. Open valve (HV76) to bleed off pressure. Remove
protective caps from the gas phase connection (C2)
and the vent line hose. Connect the hose. Close valve
(HV76).
43. Open valve (HV71) to bleed off pressure. Remove
protective caps from the liquid phase connection (C1)
and the liquid transfer hose. Connect the hose from a
hydrogen gas source. Close valve (HV71).
44. Open the hydrogen gas supply valve. Open valve
(HV71) and purge the transfer hose for ten seconds.
Close valve (HV71).
45. Open valve (HV9) and admit gaseous hydrogen to the
container. Open valve (HV11) and release purge gas to
the vent stack.
46. Obtain gas samples by opening valve (HV34). Continue
sweep purge until a gas analyzer indicates a nitrogen in
hydrogen concentration of less than 1% by volume.
47. Open valves (HV10) and (HV42). Continue sweep
purge until the nitrogen in hydrogen concentration is
less than 1% by volume. Close valve (HV10).
48. A pressure purge cycle consists of the following steps.
Close valve (HV11) and increase container pressure
to 15 psig. Allow container to remain at 15 psig for 30
minutes. Open valve (HV11) and blow down container
to 1 psig. Close valve (HV11).
49. Perform pressure purge cycles until nitrogen in
hydrogen concentration is less than 0.1% by volume.
Obtain gas samples through valve (HV34). At least three
or four pressure purge cycles are typically required
to obtain this concentration level. After final pressure
purge, leave a residual pressure of at least 5 psig in the
container.
50. Purge external piping and valves with hydrogen gas per
steps 14, 15, 16, 17, 24 and 26 of Cooldown and Purging.
51. Pressure purge the container three additional times
if hydrogen with a maximum impurity of 5 parts per
million by volume is required. For impurity of 25 parts
per million by volume, one additional pressure purge is
required. No additional pressure purges are required for
impurity of 50 parts per million by volume.
52. If impurity is based on parts per million by weight,
perform four pressure purges in addition to those
indicated in Step 11.
53. Close cold hydrogen gas supply valve. Close all valves
except valves (HV21B), (HV22B), (HV7A) and (HV7B).
54. Disconnect transfer hose from the liquid phase
connection. Replace protective cap on the connection
immediately. Replace protective cap on the transfer
hose. Open valve (HV14A).
55. Disconnect vent line hose from the gas phase
connection. Replace cap on the connection immediately.
Replace protective cap on the vent line hose.
56. Disconnect trailer ground cable. Remove wheel chocks
and move trailer to hydrogen fill area.
Normal Trailer Fill
57. Check name of product at source to ensure hydrogen is
product being loaded into trailer. Position trailer, shut-
off tractor, set brakes, and position wheel chocks.
58. Connect ground cable. Close all valves except (HV21B),
(HV22B), (HV7A) and (HV7B), and then open bleed
valves (HV71) and (HV76). Remove protective caps and
connect transfer hoses to liquid connection (C1) and the
gas phase connection (C2). Check purity by connecting
sample hose to valve (HV34) fitting and analyzing.
Purge hoses and lines while liquid supply valve is
cracked open slightly.
Note: You MUST recover the trailer flash-off
through the transfer hose connected to
the gas phase connection.
59. Blow down vessel to 2 psig. Open valve (HV11). Open
air operated valves (UV9) and (UV10). Valves HV105A,
HV105C, and HV105D must be in the “open” position
and a minimum of 30 psig air pressure is required.
60. Begin filling vessel by opening supply valve and liquid
fill valve (HV9).

Product Manual - Liquid Hydrogen Trailer Series
Operations 11
Caution! OPEN VALVES SLOWLY AND
WITH EXTREME CARE. BE
SURE ALL CONNECTIONS ARE
TIGHTENED SECURELY TO
AVOID LEAKS DURING LIQUID
TRANSFER.
61. Open supply valve and liquid fill valve (HV9) fully, and
throttle gas phase withdrawal valve (HV11) to control
vessel pressure in the range of 1 or 2 psig.
Filling by Weight
If filling by weight
1. Load the trailer with 10,160 lbs. of hydrogen at 2 psig
saturated pressure (or equivalent at alternative saturated
filling conditions.
a. The true weight of liquefied hydrogen in the trailer
is the difference between the full and empty weight,
added to the weight of the gas displaced by the
liquefied hydrogen during filling. Under the above
initial and final weighing conditions of 2 psig, the
weight of the gas displaced is 2.19% of the differential
weight, assuming that the displaced gas and the added
liquid are at saturated conditions of 2 psig.
EXAMPLE
– Differential weight before and after filling — 9942 lbs
– Weight of displaced gas = 2.19% x 9942 lbs — 218 lbs
– Total weight of liquefied hydrogen in trailer = 9942 +
218 lbs — 10160 lbs
For filling pressures where saturation is maintained, the
weight of the displaced gas is as follows:
Pressure
(PSIG)
Weight of Displaced Gas
(% of Differential Weight)
0 1.93
2 2.19
4 2.44
18 4.35
For other filling conditions where the initial and final pressures
are different or the displaced gas is not at saturation, the weight
of the displaced gas can be calculated as follows:
W=(PG/PE)/(1-PG/PE)
– W = Weight of the displaced gas expressed as a
percentage of the differential weight
– PG = Density of gas in the trailer at time of initial
weighing
– PE = Density of liquid in trailer at time of final
weighing
2. Once the total full weight has been established for each
trailer, do not exceed this weight.
3. Blow down container through vent line valve to 2 psig.
Open supply valve and top off container to replace
product lost by evaporation during blowdown.
Customer Fill
This item describes how to safely transfer liquid hydrogen
from a trailer to a customer’s tank. Throughout this
procedure, valves and connections are numbered according
to the standard numbering system used on hydrogen trailers.
These are recommended procedures for proper operation.
Always follow your company approved procedures for
unloading as well.
This trailer is equipped with air-operated emergency valves
labeled (UV9) and (UV10) as well as manually- operated
valves that are labeled (HV9) and (HV10).
Before leaving the Hydrogen Plant:
1. Perform pre-trip vehicle inspection
2. Prepare DOT required paperwork
3. Check the trailer’s road relief valve (HV14A). This valve
must be completely open for the 17-psig road relief
system to operate properly.
4. Ensure the pneumatic PB safety valve system is activated
by opening (HV32). This system should be activated at
all times.
5. Obtain the necessary personal safety equipment for
handling hydrogen (safety glasses, face shield, hard hat,
gauntlet glove, and flame-retardant suit)
Warning: Failure to wear protective
clothing and equipment while
handling cryogenic products
may result in serious personal
injury.
6. If the trailer’s pressure is too high to permit delivery
within the prescribed one-way travel time, reduce
pressure by sloshing liquid or venting. If the pressure
does not reduce to an acceptable level, contact your
supervisor.
7. Follow prescribed route to the customer

12
Operations Product Manual - Liquid Hydrogen Trailer Series
Upon arrival at the customer site:
1. Obey all customer site regulations such as yard speed
limits.
2. Properly position the vehicle so that the transfer hose
will easily reach the connection on the customer’s
tank. A transfer hose that is crimped or under tension
may leak or create other unsafe conditions during the
transfer.
Note: Extreme caution should be used when
backing up a vehicle. It may be necessary
for the driver to stop the vehicle and
inspect the area behind the vehicle a
number of times during the backing-up
operation. If someone is directing the
driver, both driver and director must
have a clear understanding of the hand
signals being used. However, the use of
a director does not relieve a driver of
responsibility for any damage caused by
the vehicle while it is backing up.
3. Put on personal safety equipment (safety glasses, face
shield, hard hat, gauntlet gloves and flame-retardant
suit).
4. Set the air brakes, shut off the tractor engine, and
remove the ignition key.
5. Remove the glad hand from the supply line (RED) and
place on the auxiliary glad hand (GREEN) to supply the
emergency valves with air.
Warning! Failure to wear protective
clothing and equipment while
handling cryogenic products
may result in serious personal
injury.
6. Properly ground the trailer before continuing with this
procedure by attaching the customer’s ground cable to
the trailer.
7. Check the trailer’s pressure gauge reading and the
working pressure indicated on the trailer. Be sure the
trailer’s pressure does not exceed its working pressure
during the unloading procedure.
a. Operating parameters of Liquid Hydrogen Trailer
b. Working Pressure: 155psi
c. Max Operating pressure for unloading: 135psi or
customer policy
8. If the customer’s tank pressure is greater than 125 psig,
contact your supervisor for further instructions before
continuing with this procedure.Activate the trailer’s
anti-tow interlock device by lowering the bayonet lever
flags. Connect transfer hose to withdrawal bayonet (C3).
9. Deactivate the trailer’s road relief system and activate
the 155 psig system by closing (HV14A), (HV14B), and
opening (HV14C).
10. Check to ensure that the trailer’s manually-operated
liquid fill and withdrawal valve (HV9) is tightly closed.
To open the air operated valves at customer tank (if
equipped) connect an airline from customer tank to
(CP1).
11. Open the trailer’s liquid phase fill and withdrawal drain/
purge valve (HV71) for unmetered withdrawals or the
trailer’s metered withdrawal drain/purge valve (HV72)
for metered withdrawals.
12. Check to make sure that the customer’s tank liquid and
gas fill valves are closed.
13. Open the customer’s fill line purge valve. A small
amount of gas may vent from the purge valve out
through the vent stack. If gas continues to vent for more
than a few seconds, close the purge valve and follow
troubleshooting instructions.
14. 16. If the customer’s purge valve stops venting,
remove the protective caps from the trailer and tank
connections. Be sure the trailer’s liquid-phase drain/
purge valves (HV71) or (HV72) and the customer’s fill
line purge valve are open before removing the protective
caps.
15. Inspect the connections for dirt and foreign material
and wipe them with a clean cloth. Inspect the “O” rings
for damage and replace them, if necessary.
16. Remove the transfer hose from the storage tube on the
trailer. Do not contaminate the hose by dragging the
connections on the ground. Be careful of sharp burrs
that may have developed on the hose connections.
Check the tank connection against the hose connection
to be sure they match. If the connections do not match,
contact the appropriate personnel; do NOT continue
with this procedure.
17. Inspect the hose end connections for damage. Wipe off
any foreign material with a clean cloth and install a new
gasket. Connect the transfer hose to appropriate trailer
connection.
Note: For unmetered withdrawals, connect
the hose to the trailer’s liquid-phase fill/
withdrawal fitting at (C1). For metered
withdrawals, connect the hose to the
trailer’s liquid-phase metered withdrawal
fitting (C3).

Product Manual - Liquid Hydrogen Trailer Series
Operations 13
18. Remove the protective cap from the other end of
the hose and inspect the nozzle piece for damage
and foreign material. Wipe the nozzle piece with a
clean cloth and insert it into the customer’s tank fill
connection so the vacuum plug is pointing toward the
ground. Tighten the clamp so that the “T” bolt is either
parallel or perpendicular to the customer pad.
Caution! Do not use tools to tighten the
hand wheel on the “T” bolt
clamp. Hand tight only.
19. Check the trailer’s gas-phase return valve (HV11) to
be sure that it is closed. Open Gas Phase Bleed Valve
(HV76). Uncap the gas-phase connection and attach
one end of the gas blowdown hose. Connect the other
end of the hose to the customer’s tank vent stack and, if
present, open the vent stack valve.
20. Purge the transfer hose by partially closing the trailer’s
liquid-phase drain/purge valves (HV9M) or (HV88)
leading to the connected hose. Purge the hose for 2
minutes through the customer fill line purge valve.
21. Close the customer’s fill line purge valve, and then the
trailer’s manually-operated liquid supply valve (HV9)
or (HV88), leaving the hose pressurized. Check all hose
connections for leaks.
22. If any leaks are found at this time or any time during
the transfer, close the liquid and gas fill valves on the
customer’s tank, and close the trailer manual liquid
supply valves (HV9) or (HV88). Relieve all pressure in
the hose by carefully opening the purge valves on the
trailer (HV91) or (HV72) and on the customer’s tank.
Correct leaks as follows:
a. Hand tighten the “T” bolt clamp.
b. Disassemble the connection, inspect the Kel-F “O”
rings for damage and replace them, if necessary.
c. Inspect and replace the hose seal, if necessary.
23. After correcting leaks, return to step 20 and restart the
purge procedure.
24. After achieving a successful leak test, vent the transfer
hose through the customer’s fill line purge valve and
then close the purge valve. Re-pressurize the transfer
hose by slowly opening the trailer’s manually-operated
liquid supply valve (HV9) or (HV88) and closing it
again. Wait 30 seconds, and then reopen the customer’s
fill line purge valve long enough to relieve the pressure
on the hose. Close the purge valve after pressure is
relieved.
25. Repeat step 24 five (5) times, or until the tank purge
valve line begins to frost. Close the customer tank fill
line purge valve after the last hose venting.
26. Open the trailer’s pressure building coil return valve
(HV42).
27. Open the trailer’s manually-operated liquid-phase
pressure building coil valve (HV10), and build the
trailer’s pressure 10 to 15 psig above the customer’s tank
pressure. Do not use the customer’s tank to pressurize
the trailer.
Warning: Do not exceed the trailer’s
Maximum Allowable Working
Pressure (MAWP), which is
marked on the trailer.
28. For unmetered delivery, proceed as follows.
a. Open the trailer’s manually-operated liquid fill and
withdrawal valve (HV9), and the customer’s tank
gas phase fill valve.
b. Go to step 33 and proceed with offloading
procedure.
29. For metered delivery, proceed as follows:
a. Open meter withdrawal valve (HV88) 1 or 2
turns, and open meter purge valve (HV72). After
approximately 2 minutes, when the meter purge
lines begin to frost, open purge valve (HV91) and
the customer’s fill line purge line. Leave valves open
until the meter’s out-of- range light goes out. Close
valve (HV72) and (HV91) and customer’s fill line
purge valve when meter cooldown is completed.
Record totalizer reading on meter.
b. Slowly open the meter withdrawal valve (HV88) on
the trailer and the customer’ gas fill valve.
30. The customer’s tank is set to operate at a designed
minimum pressure. Maintain the tank’s pressure
between its minimum pressure and its MAWP by
opening or closing the customer’s tank liquid or gas fill
valves. To lower the tank’s pressure, open the gas valve
and throttle the liquid valve; to raise it, open the liquid
valve and throttle the gas valve.
31. To unload all product from the trailer, maintain the
pressure in the trailer 10 to 15 psig greater than the
customer’s tank pressure. However, do not let the
trailer’s pressure exceed its MAWP or the safety valve
settings on the customer’s tank. Maintain the trailer’s
pressure until either the customer’s tank is full or the
trailer is empty.
Caution: Remain at the back of the trailer
during the entire unloading
procedure to take corrective
measures promptly.

14
Operations Product Manual - Liquid Hydrogen Trailer Series
32. When the customer’s tank liquid contents gauge
approaches the full mark, open the customer’s tank full
trycock valve and watch the customer’s fill termination
device (gauge).
33. When the gauge needle begins to fluctuate, or the
customer’s tank pressure begins to rise rapidly, close the
customer’s tank liquid fill valve and full trycock valve.
Close the trailer liquid supply valve (HV9) or (HV88).
34. Close the trailer’s manually operated liquid phase
pressure building coil valve (HV10). Turn off the
metering system and take a reading.
35. Disconnect the gas blowdown hose from the trailer
and vent stack, and securely cap the trailer and hose
connections.
36. Complete the required paperwork.
37. Close the trailer’s gas phase pressure building coil valve
(HV42).
38. Close air-operated valves (UV9) and (UV10) by
operating the emergency shut-off valve (HV105D) at
rear of trailer.
39. After all liquid product in the transfer hose has
vaporized, close the customer’s tank gas phase fill valve.
40. Open the customer’s fill line purge valve and the trailer’s
purge valve (HV71) for trailers without meters, or
(HV72) for trailers with meters, to vent pressure from
the transfer hose to the vent stack.
41. When the transfer hose stops venting, disconnect the
transfer hose from the trailer, pointing the end of the
hose down and away from you as you disengage the
hose from the connection. Close the purge valves on the
customer’s tank and trailer (HV71) or (HV72).
42. Disconnect the transfer hose from the customer’s
tank, and cap and store the transfer hose in the trailer’s
storage tube. Securely cap the customer’s tank liquid
connection.
43. Securely cap the trailer’s liquid connection.
44. Leak test the liquid connection cap and remove air from
the liquid line by opening and closing the trailer’s vapor
purge (HV90) or (HV91); vent through drain purge
valve (HV71) or (HV72). Remember to leave only a
slight positive pressure on this end connection. Close
valve (HV71) or (HV72). Check the connection cap
for leaks; do not attempt to repair leaks while the cap is
under pressure. Check all other valves to be sure they
are tightly closed.
45. Leak test the customer’s tank fill connection cap in the
same manner as above to remove any air from the fill
line by slightly opening and closing the gas fill valve
and venting through the tank’s purge valve. Close the
purge valve, leaving a slight positive pressure on the
end connection. Check the connection cap for leaks;
however, do not attempt to repair leaks while the cap is
under pressure.
46. Check all other tank valves that were opened during this
procedure to be sure that they are tightly closed.
47. Deactivate the trailer’s anti-tow interlock device by
raising the bayonet lever flags.
48. Remove the ground wire clamp from the trailer.
49. Recheck the customer’s tank liquid and gas fill valves to
be sure they are tightly closed.
50. Walk around the vehicle, and visually inspect to ensure
that it is safe to move.
51. Remove and store the wheel chocks and ensure cabinet
doors are closed and latched.
52. Reduce the pressure in the trailer by driving the trailer
and bringing it to a sudden stop. Repeat if necessary.
53. Check the readings on the trailer’s contents gauge (LI19)
and pressure gauge (PI20A). Determine the travel
time to the next customer or the plant. Determine the
proper road relief isolation valve settings, and whether
the trailer should be blown down before leaving the
customer’s site.
54. If blowdown is required, follow prescribed personnel
safety procedures and blowdown procedures.
Abnormal Situations
Excessive Pressure Rise
1. Empty Trailer -If pressure rise exceeds 1 psig for every 2
hours of travel time when the trailer is empty, follow the
troubleshooting instructions. This situation is critical
when the time to the next destination is greater than the
time it will take for the pressure to rise above the DOT
legal limit for travel (varies based on density; 150 psi
max at 4.5% density).
2. Full or Partially Full Trailer - If the pressure rise
exceeds 0.2 psig for every 2 hours of travel time, follow
troubleshooting instructions.
Reading Tank Pressure
1. Reading the rear pressure gauge (PI20B)
a. Open the needle valve (HV7B) on the instrument
panel and read tank pressure directly in PSIG from
gauge on the panel.

Product Manual - Liquid Hydrogen Trailer Series
Operations 15
2. Reading the front pressure gauge (PI20A)
a. Open the needle valve (HV7A) on the instrument
panel and read tank pressure directly in PSIG from
gauge on the front gauge panel.
Reading Liquid Level
To read the level of the liquid, in inches of water, proceed as
follows:
1. Check “ZERO” setting of the gauge by closing the needle
valves in the panel marked (HV21B) and (HV22B) and
opening the valve marked (HV23). Gauge needle should
read zero.
2. Close (HV23) and open (HV21B) and (HV22B). Read
inches of water directly from gauge on the panel.
3. A conversion chart in inches of water to gallons of liquid
hydrogen is mounted on the curb side compartment
door. A copy can also be found in the Trailer Dossier.
This provides approximate liquid level.
Reading Vacuum
A Teledyne Hastings Thermocouple tube (DV-6R) has been
furnished with this trailer.
1. Carefully plug gauge to tube (52A).
2. Be sure that vacuum gauge tube shut-off valve (HV52) is
open. Wait 15 minutes for stabilized reading.
3. Read vacuum in microns.
4. Close vacuum gauge valve (HV52) before removing
gauge connection (52A).
Taking a Liquid Sample
To take a liquid sample, proceed as follows:
1. Connect sampling line to sample connection (C30).
2. Open sample valve (HV34).
3. When sampling is complete, close (HV34).
Lifting Trailer Empty
Four (4) lifting lugs have been provided with this vehicle.
By using cable and shackles the trailer may be lifted or
righted by one crane or two, depending on availability. It is
recommended that all product be removed prior to lifting.
Moveable Kingpin Plate
This vehicle is equipped with an 9-position movable kingpin
Plate.
1. The trailer was assembled and delivered with the plate
in the #7 position for optimum weight distribution with
the indicated tractor.
2. Each position is 3” apart.
3. To increase trailer tandem weight, move the plate
forward.
4. To decrease trailer tandem weight, move the plate to
rear.
5. Make sure all bolts are in place and tight.
6. Recommended torque - 200 +/- 10 FT LBS
Safety Relief Valve Removal
To remove a container safety relief valve under pressure,
proceed as follows:
1. Move the handle of the diverter valve (HV59), 90
degrees. Direction of flow is shown on the valve handle.
2. Remove desired part. Trailer may not be used until
replacement or repaired part is re-installed.
Inner Vessel Repairs
If inner vessel repairs due to accident, loss of vacuum,
or other circumstances become necessary, it is strongly
suggested that the trailer be returned to Chart Industries.
Should this not be practical, the following procedure —
which will void all warranties — is suggested for access to the
inner vessel:
1. Purge the inner vessel per procedures in this manual.
2. Break the vacuum in the annular space and purge with
nitrogen gas.
3. Locate, mark and cut a 24” x 24” hole the center of
which is 31 inches from the front head to shell weld and
22 inches along the circumference from the top center
line of the casing, road side.
4. Remove a 22” x 18.5” section of the insulation.
5. Cut an appropriate manway.
6. When repairs are completed clean the container of
particles and contaminants.
7. Seal the access hole with a backing ring and a manway
cover.

16
Operations Product Manual - Liquid Hydrogen Trailer Series
8. Mass Spectrometer, and UT Test the weld.
9. Restore insulation to container at manway.
10. Seal casing access hole with lap patch.
11. Restore vacuum to annular space.
12. Mass Spectrometer Test casing.
Note: Chart Inc. takes no responsibility for the
implementation of the above described
procedure. This is a very difficult
operation and should be performed by
experienced, qualified organizations with
A.S.M.E. certifications.
Note: All warranties pertaining to thermal and
structural performance or integrity of the
container, casing, and insulation system
are voided if this work is not done at a
Chart facility.
Suspension Air Bag Dump Valve
A manually operated toggle valve to quickly empty the
Hendrickson suspension air bags has been provided. It is
installed inside the rear compartment on the roadside valve
panel. It is recommended that the air bags be emptied before
disconnecting the tractor and loading or unloading product
from the trailer. Before driving off, make sure the valve is in
the “suspension up” position. Emptying the bags will lower
the piping compartment approximately 3”.
Flowmeter Operation
For flowmeter operating instructions please refer to
manufacturer’s manual in the Trailer Dossier.