Procurement Specification for a 1500 Gallon Skid Mounted Liquid Methane
Dewar

February 24, 2006

White Sands Test Facility

Propulsion Department

Introduction:

The purpose of this procurement is the purchase of one skid mounted 1500
gallon Liquid Methane Dewar to provide propellant storage for testing of
Liquid Methane based rocket engines. The initial use for the vessel will
be a holding/transfer storage vessel, however the design of this Dewar
will be such as to make it portable and movable (with a full load of
Liquid Oxygen or Liquid Methane), to make it convertible for use as a
run tank later on (high MAWP and fluid transfer capability), and design
the Dewar so that it can be used for higher density cryogenic liquids in
the future if needed (Liquid Oxygen with a soft goods change). Safety
being of the highest concern all applicable codes will be followed.

Primary Requirements:

1\. Liquid capacity with required ullage allowance shall be no less than
1500 U.S. standard gallons.

2\. The MAWP for the inner vessel shall not be less than 500 Psia.

3\. The withdrawal nozzle shall have the capability to pass 12 pounds
per second of Liquid Methane. The rate shall be based on the lowest
typical density for the liquid based on 99% pure Liquid Methane.

4\. The vessel shall be enclosed with an ISO rated structural enclosure.
The structure shall have a lifting eye at the each corner. The structure
shall be rated to lift the entire skid including the vessel with a full
load of Liquid Oxygen using the required safety factor.

5\. The vessel shall come completely piped, thermal shocked, leaked
checked, cleaned and ready for use. The thermal shock will involve
introducing liquid nitrogen to the Dewar to chill the Dewar down. Once
the Dewar is chilled the systems shall be leak checked at cryogenic
conditions. Cleaning level shall be 100A per SN-C-005 revision D.
SN-C-005, Revision D (Space Shuttle Contamination Control Requirements
Revision D July 20, 1998).

6\. All documentation on the skid must be submitted and approved before
the skid will be accepted. Review and acceptance of documentation by
WSTF does not relieve the supplied from the obligation to meet the
required codes.

Governing codes:

The following codes shall apply to this procurement and the vendor has
the sole responsibility to ensure compliance with these codes. Any other
applicable codes not listed in the procurement shall also be considered.
In the event there is a conflict between given codes, the more stringent
code shall apply. The latest edition or publication of a code or law
will be used.

1\. Title 49 Code of Federal Regulations (CFR), Part 193 (flammable
liquids)

2\. National Fire Protection Association (NFPA) section 59A Standards
for the Production, Storage and Handling of Liquefied Natural Gas (LNG)

3\. Title 49 CFR, Part 178 (transport of flammable liquids) (DOT 4L)

4\. Title 29 CFR, personnel safety associated with OSHA regulations

5\. American Society of Mechanical Engineers (ASME) Section VIII,
Division I Boiler and Pressure Vessel Code

6\. ASME section B31.3 Process Piping

7\. American National Standards Institute (ANSI) / NFPA 30 Flammable and
Combustible Liquid Code

8\. NFPA 70 (National Electrical Code)

9\. NFPA 325 Guide to fire hazards properties for flammable liquids,
gases

10\. NFPA 497 Recommended practices for the classifications of flammable
liquids, gases or vapors of hazardous locations for electrical
installations in chemical process areas.

11\. NFPA 77 Static Electricity

Note: The vendor will be solely responsible for ensuring that all
materials used (both metals and soft goods) will be compatible with
Liquid Methane and Liquid Oxygen in the given temperature and pressure
ranges. If the Dewar is switched from Liquid Methane to Liquid Oxygen
the soft goods would be changed (by the owner) as a requirement of a
conversion.

White Sands Test Facilities Pressure Vessel/ System program:

White Sands Test Facility has requirements specific and internal to the
site. All pressure systems must have a pressure vessel/system
documentation package (PV/S). This package will include the pedigree of
every component in the pressure system. This will include the vessel
(ASME U-1 form), fittings, hard lines, valves, and instrumentation. It
will include every item subjected to the system pressure. A requirement
of this procurement is to provide this information. For most items it
will include the manufacture of the part, the manufacture's part and
serial numbers, MAWP (both of the body and the soft goods) , material of
the part (both hard parts and soft goods), size, type of connection (AN
fitting, flanged, etc.) and any specific remarks (on a PCV the orifice
sizing and the spring number). For all relief devices a calculation will
be required to ensure the relief valve will meet the manufacture's
specifications in regards to flow. For hard lines they will need to be
proofed per ASME B31.3 requirements and tagged with a metal etched tag
listing the material type, wall thickness, size and MAWP based on proof.
Instrument and piping diagrams will be provided in both AutoCAD and hard
copy by the vendor as part of this procurement for the PV/S package.

Vendor Requirements:

The vendor shall be competent in the design, fabrication, and
construction of Liquid Methane containers. The vendor shall be required
to submit credentials and a list of completed methane Dewar projects to
WSTF for verification of qualifications. Vendor must be a National Board
registered fabrication shop per ASME requirements. Vendor's failure to
submit this documentation will be considered a non responsive bid.

Vessel specifications:

Inner Vessel:

The inner vessel shall be fabricated from 304 stainless steel and shall
have a rating of 500 Psig internal maximum allowable working pressure
(MAWP). This MAWP shall be based on the requirement of the customer (500
Psia) a 15 psi allowance for vacuum annulus and the hydrostatic pressure
of the liquid against the vessel. The vessel shall be designed for a
minimum allowable internal pressure of 5 Psia. The inner vessel will be
used for methane; however the structural design (for liquid density,
temperature, etc.) for the inner vessel needs to be based on the use of
Liquid Oxygen in the event the decision is made to use this Dewar for
other applications beyond Liquid Methane testing. All requirements of
ASME section VIII, division I of the boiler and pressure vessel code
shall apply. The vessel SHALL be registered with the National Board.

A nameplate shall be clearly attached to the outer vessel exterior with
the required inner and outer vessel and at minimum will have information
such as vendor/ fabricators name(s) and addresses(s), fabricators
National Board registration number, date of fabrication, inspection
types done, material type and thickness for heads and shell, the
applicable pressure ratings and temperature ranges, the ASME "U" stamp
and the national board registration number. Complete U-1 forms, shop
inspection forms and all applicable documentation in regards to testing
will be supplied to WSTS. All mill reports on materials used in the
inner vessel construction shall also be submitted to WSTF. Stress design
of the vessel shall include analysis for seismic conditions, in addition
to all other design considerations, per NFPA 59A requirements. The
seismic zone to use will be for the Las Cruces, New Mexico area. The ISO
cage will have bolt hole previsions to anchor the skid to the ground. A
name plate shall also be attached to the outer vessel and will contain
the information required by NFPA 59A section 7.5

WSTF reserves the right to witness the hydrostatic proof of the inner
vessel. The vendor shall contact Sean Gates at 505 524-5718 no less than
4 weeks in advance of the scheduled hydrostatic test so arrangements for
travel can be made.

Outer Vessel:

The outer vessel shall be constructed of carbon steel complying with
Section VIII, division I of the ASME code at temperatures at or above
the minimum allowable temperature as listed in table 1A of the ASME code
section II, part D. The insulation of the annulus space shall be with
use of multiple layer insulation and vacuum, therefore the design of the
outer vessel shall be based on ASME section VIII parts UG-28, UG-29, UG-
30 and UG -33 using an external pressure of not less than 15 psi.

The outer vessel shall have a relief device that complies with NFPA 59A
requirements and ASME section VIII division I requirements.

The outer vessel shall have supports and mounting brackets installed as
needed to ensure that all items to be affixed to the outer vessel are
secure. The calculations for these supports shall include thrust induced
by discharge of relief devices and valves.

A tag shall be provided for the outer vessel as well that shall contain
the same information as the tag for the inner vessel.

Supports for vessel:

The supports for the inner vessel to the cage structure shall be
designed to provide support for the high density liquid use (Liquid
Oxygen) in the future but shall be designed to provide minimum heat
loss. The design for the supports shall be such as to account for the
dynamic loading caused by lifting, loading and moving a full container
of liquid over the road at speeds up to 45 miles per hour, seismic
loading for the Las Cruces, New Mexico area and all other applicable
design considerations such as temperature variance and densities of the
liquid (based on LOX). The supports shall meet all requirements of NFPA
59A including fire ratings and shielding for cold conditions as
necessary. Connection to the outer vessel shall be in accordance with
ASME and NFPA requirements. The vendor shall supply documentation of
compliance for seismic loading per the NFPA 59A requirements.

Nozzles:

Nozzle configuration will be based on the requirements of NFPA 59A, the
standard piping for a typical methane Dewar and the requirements of the
customer for liquid withdrawal rate and ullage pressurization
capabilities.

Since the nozzles are part of the pressure vessel and will be in the
annular space between the inner and outer vessel, all requirements of
ASME section VIII, Division I and NFPA 59A apply. ALL information on
nozzles SHALL be included on the U-1 form for the inner vessel. No
bellows will be allowed in the annulus space between the inner and outer
vessel. All fitting connections for the nozzles outside the vessel shall
be flared AN connection with the exception of the 3" withdrawal line.

1\. Tank fill - NFPA 59A requires a top and bottom fill capability to
prevent overfill.

a\. Top fill shall be a 1 ½" nozzle entering the top of the inner vessel
and shall have a device to prevent overfilling.

b\. Bottom fill shall have a 1 ½" nozzle entering the bottom of the
inner vessel and shall have a device to prevent overfilling.

2\. Bottom tapping nozzles for liquid withdrawal.

a\. Supply one nozzle capable of supplying the required 12 pounds per
second flow. It is assumed the approximate size of this nozzle to be 3"
NPS, however the vendor shall calculate flow to confirm this and provide
the appropriate sized nozzle. This information shall be supplied to WSTF
ASAP so vacuum jacket piping can be ordered.

b\. Provide a second nozzle for possible future use such as a pump loop
or secondary withdrawal point. This nozzle shall be 2" NPS.

3\. Top tapping nozzles for vent, relief and tank ullage pressurization.

a\. Provide a nozzle at the top of the tank for venting, back pressure
control valve and relief devices. The vendor shall size this nozzle
based on the design of the tank and requirements of NFPA 59A and ASME
division VIII, section I.

The vent nozzle shall be sized based on the "worst case situation" based
on the temperature/pressure/density and the cryogen in the inner vessel
(Liquid Methane, LOX). In no case shall this nozzle be less than 1 ½"
NPS.

b\. Provide a nozzle in the top of the inner vessel that is 1 ½" NPS.
This nozzle will be used to supply helium pressure to the ullage space
to move Liquid Methane. It will also be used to purge the tank during
filling operations. Provide this nozzle with a blind flange.

4\. Instrumentation nozzles

a\. Supply one nozzle bottom inner vessel for liquid level
instrumentation (liquid line). The nozzle will be ½" NPS

b\. Supply one nozzle top inner vessel for liquid level instrumentation
and pressure indicator. The nozzle will measure vapor pressure. The
nozzle will be 3/8" NPS

c\. Supply one nozzle top inner vessel with tube continuing down to the
normal liquid level for the inner vessel. This will be for the full
trycock line. The nozzle will be 5/8" NPS

Total nozzles for this Dewar will be 9 each with 6 each exceeding 1" NPS
and 3 each less than 1" NPS.

Dewar Insulation and Annular space requirements:

MLI Insulation

The inner vessel shall be insulated with multiple layer insulation
(MLI). The insulation shall be Mylar/ foil. The minimum number of layers
shall be no less than 30. The vendor shall supply heat leak information
on their proposed Dewar with their bid.

Vacuum Annulus

The annulus shall be evacuated. The vendor shall apply a vacuum to the
annulus prior to shipping. The outer vessel shall have a port with valve
assembly for vacuum pump down with an external vacuum source and a port
with isolation valve. On the down stream side of the isolation valve a
vacuum gauge (electronic readout) (Hastings) shall be provided. The
calibration curve and product literature shall be supplied with the
vacuum gauge.

Dewar Piping:

The Dewar will be purchased as a complete unit ready for use by WSTF. As
such the vendor shall supply, clean, install and leak check all piping
required. All metals, materials, and soft goods shall be compliant with
Liquid Methane and Liquid Oxygen service at the pressures and
temperatures indicated. For all lines except the 3" withdrawal the means
of connection shall be flared AN fittings. The 3" withdrawal line will
be a clamped style bayonet fitting. The MAWP of all components and hard
lines shall match that of the vessel (500 MAWP). Requirements of the
WSTF pressure vessel system packages shall apply. A copy of the WSTF
PV/S requirements shall be included as a part of this bid requirement.
All requirements of NFPA 59A and ASME B31.3 process piping shall apply.

1\. Filling piping.

The vessel will be supplied with the two 1 ½" ID inlets (top and bottom)
for filling of the Dewar with Liquid Methane. A non-vacuum jacketed
extended stem cryogenic rated manual valve shall be supplied for both
fill lines (one for each fill line). These two valves shall then be
piped together to a tee. The tee shall be connected to a 15 foot long
filling hose 1 ½" diameter. The fill hose shall be rated for use with
Liquid Methane and shall have a stainless steel braid outer jacket. The
connection for the fill hose to the transfer Dewar/tanker shall be a
LNG-30 liquefied natural gas connection standard for cryogenic fluid
transfer per CGA V-6-2000 (CGA --compressed gas association). The
connector is a 3" diameter connection and will need to be reduced down
to connect to the flex line. The flex line will not be vacuum jacketed.
A connection shall be included to provide an inert purge of Helium to
the fill line to evacuate methane vapor prior to disconnection of the
line (NFPA 59A).

2\. Bottom tappings.

The 2" line bottom taping will have one non- vacuum jacketed extended
stem cryogenic rated manual valve. The outlet of the valve shall be
capped for possible future use and the valve and cap insulated.

The 3" line bottom taping for liquid withdrawal shall be vacuum jacketed
from the nozzle exit of the outer vessel on out. A 3" vacuum jacketed,
extended stem cryogen rated remote operated valve (ROV) shall be
installed on the nozzle. The ROV valve body shall be for open/close
operation (not throttling) and the CV shall be such that the 12 pound
per second requirement is achieved downstream of the valve. The valve
shall be a normally closed valve with spring tension (for product
retention purposes).

The valve will have electrical operator 24 VDC and will either be
intrinsically safe or will be supplied with seal off protection. The
requirements for power for the operator shall be supplied to WSTF as
soon as the operator is selected. The valve is not required to be fast
acting on opening but will be fast acting on closing with the spring
actuation for failing to the closed position. The operator should be
replaceable in the future should the decision be made later to use
muscle pressure or a fast acting valve operator.

On the outlet of the valve the vacuum jacket piping will continue to a
bayonet connection point (flanged and clamped type). The bayonet
connection shall be for typical connection to vacuum jacketed piping and
will be supplied with the end protector cap, four additional "o" clamps
(to connect to the VJ pipe) and 10 each additional o-ring seals (or
other required seals). The piping and bayonet connection shall be
installed within the confines of the cage to prevent damage to the
nozzle, bayonet, or piping.

All valves and piping shall piped up as close as reasonably possible
while allowing room to service the equipment. The vendor shall consider
"liquid lock" conditions in piping layout and will make provision is
needed. Liquid lock occurs when the cryogenic liquid flashes to vapor
between two closed valves and expands. The vendor shall perform
calculations of this and provide them to WSTF to ensure hard lines will
not rupture in short runs.

In longer runs where the pressure from expansion will cause a rupture, a
relief valve will have to be installed between any two valves (or other
sources) that can restrict flow and cause over pressurization. For the
purposes of rupture calculations for hard lines, the safety factor of 4
is applied. In other words the pressure induced on the hard line from
liquid lock must be four times less than the rupture or failure pressure
of the hard line.

3\. Top tapings for the vent, relief devices and ullage pressurization

The top taping for the vent, pressure backpressure regulator and relief
devices will be sized based on requirements on AMSE division VIII
section I and NFPA 59A. It will be based for the worst case situation
based on the required pressures and temperatures. Where the discharge
from multiple vent sources is ganged, the vent piping shall be sized to
ensure that no backpressure is exerted on one device from the discharge
of another device. Based on NFPA 59A requirements for relief devices,
WSTF would prefer to use a 3 way valve for relief device selection in
lieu of using lockable valves. The three way valve will allow the
servicing on one set of relief devices and ensure the other set of
relief devices are in service. Provisions to purge methane from either
relief system circuit for servicing is required per NFPA 59A and must be
included. The nozzle for vent, relief and Dewar pressure control will
need to be branched off for the various legs. One leg will include the
relief circuit and can utilize pressure relief valves only or both
pressure relief valves and rupture disk. If rupture disks are used the
vendor shall supply 2 spare disks for each rupture disk device used. The
vendor shall perform calculations for all relief devices ensuring that
they meet the manufacture's stated performance and all ASME and NFPA
requirements and will submit these calculations as part of the
procurement.

The pressure control circuit shall include a back pressure regulator to
maintain the Dewar set pressure at a given point. The backpressure
regulator will have an isolation valve and a bypass valve. These valves
shall be manual, non vacuum jacketed, extended stem cryogenic valves.
The backpressure regulator, associated piping and valves shall be sized
based on the estimated boil off for the Dewar in the worst case
situation (low liquid) and for the typical highest temperatures and
solar radiation conditions for the Las Cruces, New Mexico area.

Supply a vent stack with weather cap for the Dewar. This stack can be
removable for transport. A flanged connection with appropriate seal is
acceptable for the skid.

Provide a storage location for the elevated section of vent stack on the
skid when the skid is being transported.

A tank pressurization nozzle will be included at the inner vessel. This
connection will allow the use of Helium to pressurize and move the
propellant. It will also allow for introduction of inert gas during
filling of the Dewar (initial fill).

The nozzle will be used for both pressurization and venting of the
system. On the 1 ½" line install a tee. One side of the tee will be used
for the pressurization system and the other side will be used for
venting. On the pressurization side install the flowing items in the
listed order from the tee outward.

Install a 25 micron filter, cryogen rated double check valve, a 1 ½"
helium rated ECV (open/close 24 VDC) valve (intrinsically safe or
provide with seal offs ) , a 1 ½" manual helium rated valve, and a tee.
On the out branch of the tee install a pressure relief valve. At the
through branch of the tee install a short hard line with a cap. The cap
will be the point where an external regulated helium source will be
connected to pressurize the system. All components will be rated for the
500 MAWP of the Dewar and the relief at the tee will protect the system
should the regulated source fail.

On the other side of the tee install 1 ½" tee with a pressure indicator,
a cryogenic rated ECV (open/close 24 VDC) valve (intrinsically safe or
with seal offs) and a manual non vacuum jacketed, extended stem, cryogen
rated 1 ½" manual valve. This will be used as the vent system. Pipe the
outlet of the vent system up and away from personnel level around the
skid. Pipe the pressure relief valve on the pressure outlet side to the
same vent stack.

A diagram of the typical piping is included below.

![](media/image1.png){width="10.001388888888888in"
height="11.355555555555556in"}

4\. Instrumentation piping

Using the upper and lower liquid level nozzles, install a manual liquid
level indicator Install cryogen rated, non vacuum jacketed, extended
stem valves to isolate both of the liquid level lines. Provide an
equalization valve between the two inlets on the manual liquid level
indicator. On the high liquid level line side (vapor) install a pressure
indicator.

Install a non vacuum jacketed, extended stem cryogen rated manual valve
for the full trycock. Provide loop/sight glass on valve discharge side
and pipe over to the ganged vent stack.

Cage, cabinet and other items

The skid shall have a cage that total encloses ALL parts of the Dewar.
The exceptions will be vent stack for the inner vessel vent, relief
system and Dewar pressure control. The vent riser will be removable for
transport. When the Dewar is placed and the vent stack riser is
installed the riser will be outside of the cage area.

The cage shall comply with ISO and DOT requirements for Liquid Methane
ISO skid containers. The skid shall be structurally designed to lift the
Dewar when it is full of product (based on the higher density of LOX)
with a safety factor of 4. The cage shall be designed for seismic loads
based on the appropriate seismic factor for the Las Cruces, New Mexico
area. The cages shall also be designed for dynamic loads based on the
loading and transport of the vessel at speeds up to 45 mile per hour.
The cage shall have a lifting point at each corner and shall be sized
for the same safety factor for the cage when the Dewar is full. The cage
shall have provisions for securing the skid down to a trailer or the
ground. The cage shall also be bounded to the vessels and have a
connection point for connection to a grounding grid system. A grounding
buss and reel with clip connection will be provided for connection to
the transfer Dewar/tanker. Grounding shall meet the requirements of
NFPA. Provide structural mounting areas on each side of the vessel in
the structure of the cage for mounting additional equipment (to be added
on site). The supports need to cross members that provide no less than 4
foot width and 4 foot high (at a 5' 6" height from the bottom of the
skid) and support 1000 lbs. Provide a mounting area like this on each
side of the vessel near the valve section of the skid. The cage shall be
constructed of carbon steel, prepped and painted. The vendor shall
provide calculations and/or modeling for the cage to WSTF.

Provide a valve cabinet around the valve assembly. The cabinet will be
painted carbon steel with non locking double swinging doors. The bayonet
outlet will extend through a penetration in the cabinet such that the VJ
line can be connected to the bayonet connector and the doors on the
cabinet can remain closed. Likewise the bayonet shall be installed in
such a way as to not interfere with access to items inside the cabinet.

Labeling

The vendor will label all components with permanent metal tags and
provide a laminated component list, and instrument and piping diagram
attached to the inside of the cabinet door. The Dewar and all components
shall be labeled in accordance with NFPA, DOT and all other applicable
requirements.

Thermal shocking, leak checking and cleaning.

Once the vessel is complete the vendor shall thermal shock the skid
using liquid nitrogen and check for leaks. Any leaks shall be repaired
and the tank shall be thermal shocked again until all leaks (under
typical cryogen conditions) are repaired and the system is certified as
leak free.

The skid and all components included shall be cleaned to 100 level per
SN-C-005 revision D. This will be certified by the vendor and the firm
used to clean the system. WSTF will sample the Dewar and components for
cleaning level when the Dewar is received. Failure of cleaning will be
grounds for rejection until the Dewar meets the standard.

WSTF will conduct an acceptance inspection of the Dewar when it arrives
to ensure compliance. Based on circumstances a vendor representative may
be requested to be on site during the inspection. Inspection and
acceptance by WSTF DOES NOT relieve the vendor of compliance with codes
and stated requirements.

WSTF reserves the right to review all calculations. The Vendor shall
provide WSTF a schedule of events for the fabrication of the Dewar. WSTF
reserves the right to visit the vendor's facility during any point in
fabrication to inspect the Dewar. The vendor shall make WSTF aware of
any changes in schedule for the work.

Reference Documents:

White Sands Test Facility Standard Instructions WSI 09-SW-0005.H
Certification, Recertification, and Deactivation of WSTF Pressure
Vessels and Pressurized Systems (PV/S)

Space Shuttle Contamination Control Requirements Revision D July 20,
1998 SN-C-005-RevD

Both Documents are available on request. The vendor must comply with the
requirements of both documents.