Source: http://www.google.com/patents/US6212891?ie=ISO-8859-1
Timestamp: 2015-03-05 12:14:52
Document Index: 651649109

Matched Legal Cases: ['Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'Application No. 09', 'art 1', 'art 1']

Patent US6212891 - Process components, containers, and pipes suitable for containing and ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsProcess components, containers, and pipes are provided that are constructed from ultra-high strength, low alloy steels containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.)....http://www.google.com/patents/US6212891?utm_source=gb-gplus-sharePatent US6212891 - Process components, containers, and pipes suitable for containing and transporting cryogenic temperature fluidsAdvanced Patent SearchPublication numberUS6212891 B1Publication typeGrantApplication numberUS 09/099,569Publication dateApr 10, 2001Filing dateJun 18, 1998Priority dateDec 19, 1997Fee statusLapsedAlso published asCA2315015A1, CA2315015C, CN1110642C, CN1301335A, DE19882878T0, DE19882878T1, EP1040305A1, EP1040305A4, WO1999032837A1Publication number09099569, 099569, US 6212891 B1, US 6212891B1, US-B1-6212891, US6212891 B1, US6212891B1InventorsMoses Minta, Lonny R. Kelley, Bruce T. Kelley, E. Lawrence Kimble, James R. Rigby, Robert E. SteeleOriginal AssigneeExxonmobil Upstream Research CompanyExport CitationBiBTeX, EndNote, RefManPatent Citations (38), Non-Patent Citations (15), Referenced by (14), Classifications (129), Legal Events (7) External Links: USPTO, USPTO Assignment, EspacenetProcess components, containers, and pipes suitable for containing and transporting cryogenic temperature fluids
(a) a pump casing suitable for containing pressurized liquefied natural gas at a pressure of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature of about −123� C. (−190� F.) to about −62� C. (−80� F.), said pump casing being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized liquefied natural gas; and (b) a drive coupling. 11. A flare system comprising:
(a) a flare line suitable for containing a fluid at a pressure higher than about 1035 kPa (150 psia) and a temperature lower than about −40� C. (−40� F.), said flare line being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized fluid; and (b) a flare scrubber. 12. A flare system comprising:
(a) a flare line suitable for containing pressurized liquefied natural gas at a pressure of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature of about −123� C. (−190� F.) to about −62� C. (−80� F.), said flare line being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized liquefied natural gas; and (b) a flare scrubber. 13. A flowline distribution network system comprising:
(a) at least one storage container suitable for containing a fluid at a pressure higher than about 1035 kPa (150 psia) and a temperature lower than about −40� C. (−40� F.), said at least one storage container being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized fluid; and (b) at least one distribution pipe. 14. A flowline distribution network system comprising:
(a) at least one distribution pipe suitable for containing a fluid at a pressure higher than about 1035 kPa (150 psia) and a temperature lower than about −40� C. (−40� F.), said at least one distribution pipe being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized fluid; and (b) at least one storage container. 15. A flowline distribution network system comprising:
(a) at least one storage container suitable for containing pressurized liquefied natural gas at a pressure of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature of about −123� C. (−190� F.) to about −62� C. (−80� F.), said storage container being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized liquefied natural gas; and (b) at least one distribution pipe. 16. A flowline distribution network system comprising:
(a) at least one distribution pipe suitable for containing pressurized liquefied natural gas at a pressure of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature of about −123� C. (−190� F.) to about −62� C. (−80� F.), said distribution pipe being constructed by joining together a plurality of discrete plates of materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.), wherein joints between said discrete plates have adequate strength and toughness at said pressure and temperature conditions to contain said pressurized liquefied natural gas; and (b) at least one storage container. Description
This invention relates to process components, containers, and pipes suitable for containing and transporting cryogenic temperature fluids. More particularly, this invention relates to process components, containers, and pipes that are constructed from an ultra-high strength, low alloy steel containing less than 9 wt% nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.).
Frequently in industry, there is a need for process components, containers, and pipes that have adequate toughness to process, contain, and transport fluids at cryogenic temperatures, i.e., at temperatures lower than about −40� C. (−40� F.), without failing. This is especially true in the hydrocarbon and chemical processing industries. For example, cryogenic processes are used to achieve separation of components in hydrocarbon liquids and gases. Cryogenic processes are also used in the separation and storage of fluids such as oxygen and carbon dioxide.
There are a wide variety of applications in which pumps are used to move cryogenic liquids in process and refrigeration systems where the temperature can be lower than about −73� C. (−100� F.). Additionally, when combustible fluids are relieved into a flare system during processing, the fluid pressure is reduced, e.g., across a pressure safety valve. This pressure drop results in a concomitant reduction in temperature of the fluid. If the pressure drop is large enough, the resulting fluid temperature can be sufficiently low that the toughness of carbon steels traditionally used in flare systems is not adequate. Typical carbon steel may fracture at cryogenic temperatures.
Although some commercially available carbon steels have DBTTs as low as about −46� C. (−50� F.), carbon steels that are commonly used in construction of commercially available process components and containers for hydrocarbon and chemical processes do not have adequate toughness for use in cryogenic temperature conditions. Materials with better cryogenic temperature toughness than carbon steel, e.g., the above-mentioned commercial nickel-containing steels (3 � wt % Ni to 9 wt % Ni), aluminum (Al-5083 or Al-5085), or stainless steel are traditionally used to construct commercially available process components and containers that are subject to cryogenic temperature conditions. Also, specialty materials such as titanium alloys and special epoxy-impregnated woven fiberglass composites are sometimes used. However, process components, containers, and/or pipes constructed from these materials often have increased wall thicknesses to provide the required strength. This adds weight to the components and containers which must be supported and/or transported, often at significant added cost to a project. Additionally, these materials tend to be more expensive than standard carbon steels. The added cost for support and transport of the thick-walled components and containers combined with the increased cost of the material for construction tends to decrease the economic attractiveness of projects.
Consistent with the above-stated objects of the present invention, process components, containers, and pipes are provided for containing and transporting cryogenic temperature fluids. The process components, containers, and pipes of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel, preferably containing less than about 7 wt % nickel, more preferably containing less than about 5 wt % nickel, and even more preferably containing less than about 3 wt % nickel. The steel has an ultra-high strength, e.g., tensile strength (as defined herein) greater than 830 MPa (120 ksi), and a DBTT (as defined herein) lower than about −73� C. (−100� F.).
These new process components and containers can be advantageously used, for example, in cryogenic expander plants for natural gas liquids recovery, in liquefied natural gas (�LNG�) treating and liquefaction processes, in the controlled freeze zone (�CFZ�) process pioneered by Exxon Production Research Company, in cryogenic refrigeration systems, in low temperature power generation systems, and in cryogenic processes related to the manufacture of ethylene and propylene. Use of these new process components, containers, and pipes advantageously reduces the risk of cold brittle fracture normally associated with conventional carbon steels in cryogenic temperature service. Additionally, these process components and containers can increase the economic attractiveness of a project.
The present invention relates to new process components, containers, and pipes suitable for processing, containing and transporting cryogenic temperature fluids; and, furthermore, to process components, containers, and pipes that are constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.). Preferably, the ultra-high strength, low alloy steel has excellent cryogenic temperature toughness in both the base plate and in the heat affected zone (HAZ) when welded.
Process components, containers, and pipes suitable for processing and containing cryogenic temperature fluids are provided, wherein the process components, containers, and pipes are constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.). Preferably the ultra-high strength, low alloy steel contains less than about 7 wt % nickel, and more preferably contains less than about 5 wt % nickel. Preferably the ultra-high strength, low alloy steel has a tensile strength greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). Even more preferably, the process components, containers, and pipes of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.).
A co-pending U.S. patent application (�the PLNG Patent Application�), entitled �Improved System for Processing, Storing, and Transporting Liquefied Natural Gas�, describes containers and tanker ships for storage and marine transportation of pressurized liquefied natural gas (PLNG) at a pressure in the broad range of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature in the broad range of about −123� C. (−190� F.) to about −62� C. (−80� F.). The PLNG Patent Application has a priority date of Jun. 20, 1997 and is identified by the United States Patent and Trademark Office (�USPTO�) as Application No. 09/099,268 and has been published in WO 98/59085. Additionally, the PLNG Patent Application describes systems and containers for processing, storing, and transporting PLNG. Preferably, the PLNG fuel is stored at a pressure of about 1725 kPa (250 psia) to about 7590 kPa (1100 psia) and at a temperature of about −112� C. (−170� F.) to about −62� C. (−80� F.). More preferably, the PLNG fuel is stored at a pressure in the range of about 2415 kPa (350 psia) to about 4830 kPa (700 psia) and at a temperature in the range of about −101� C. (−150� F.) to about −79� C. (−110� F.). Even more preferably, the lower ends of the pressure and temperature ranges for the PLNG fuel are about 2760 kPa (400 psia) and about −96� C. (−140� F.). Without hereby limiting this invention, the process components, containers, and pipes of this invention are preferably used for processing PLNG.
Any ultra-high strength, low alloy steel containing less than 9 wt % nickel and having adequate toughness for containing cryogenic temperature fluids, such as PLNG, at operating conditions, according to known principles of fracture mechanics as described herein, may be used for constructing the process components, containers, and pipes of this invention. An example steel for use in the present invention, without thereby limiting the invention, is a weldable, ultra-high strength, low alloy steel containing less than 9 wt % nickel and having a tensile strength greater than 830 MPa (120 ksi) and adequate toughness to prevent initiation of a fracture, i.e., a failure event, at cryogenic temperature operating conditions. Another example steel for use in the present invention, without thereby limiting the invention, is a weldable, ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength of at least about 1000 MPa (145 ksi) and adequate toughness to prevent initiation of a fracture, i.e., a failure event, at cryogenic temperature operating conditions. Preferably these example steels have DBTTs of lower than about −73� C. (−100� F.).
Recent advances in steel making technology have made possible the manufacture of new, ultra-high strength, low alloy steels with excellent cryogenic temperature toughness. For example, three U.S. patents issued to Koo et al., U.S. Pat. Nos. 5,531,842, 5,545,269, and 5,545,270, describe new steels and methods for processing these steels to produce steel plates with tensile strengths of about 830 MPa (120 ksi), 965 MPa (140 ksi), and higher. The steels and processing methods described therein have been improved and modified to provide combined steel chemistries and processing for manufacturing ultra-high strength, low alloy steels with excellent cryogenic temperature toughness in both the base steel and in the heat affected zone (HAZ) when welded. These ultra-high strength, low alloy steels also have improved toughness over standard commercially available ultra-high strength, low alloy steels. The improved steels are described in a co-pending U.S. patent application entitled �ULTRA-HIGH STRENGTH STEELS WITH EXCELLENT CRYOGENIC TEMPERATURE TOUGHNESS�, which has a priority date of Dec. 19, 1997 and is identified by the United States Patent and Trademark Office (�USPTO�) as Application No. 09/099,649 and has been published in WO 99/32672; in a co-pending U.S. patent application entitled �ULTRA-HIGH STRENGTH AUSAGED STEELS WITH EXCELLENT CRYOGENIC TEMPERATURE TOUGHNESS�, which has a priority date of Dec. 19, 1997 and is identified by the USPTO as Application No. 09/099,153 and has been published in WO 99/32670; and in a co-pending U.S. patent application entitled �ULTRA-HIGH STRENGTH DUAL PHASE STEELS WITH EXCELLENT CRYOGENIC TEMPERATURE TOUGHNESS�, which has a priority date of Dec. 19, 1997 and is identified by the USPTO as Application No. 09/099,152 and has been published in WO 99/32671. (collectively, the �Steel patent applications�).
The new steels described in the Steel patent applications, and further described in the examples below, are especially suitable for constructing the process components, containers, and pipes of this invention in that the steels have the following characteristics, preferably for steel plate thicknesses of about 2.5 cm (1 inch) and greater: (i) DBTT lower than about −73� C. (−100� F.), preferably lower than about −107� C. (−160� F.), in the base steel and in the weld HAZ; (ii) tensile strength greater than 830 MPa (120 ksi), preferably greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi); (iii) superior weldability; (iv) substantially uniform through-thickness microstructure and properties; and (v) improved toughness over standard, commercially available, ultra-high strength, low alloy steels. Even more preferably, these steels have a tensile strength of greater than about 930 MPa (135 ksi), or greater than about 965 MPa (140 ksi), or greater than about 1000 MPa (145 ksi).
As discussed above, a copending U.S. patent application, having a priority date of Dec. 19, 1997, entitled �Ultra-High Strength Steels With Excellent Cryogenic Temperature Toughness�, and identified by the USPTO as Application No. 09/099,649 and has been published in WO 99/32672, provides a description of steels suitable for use in the present invention. A method is provided for preparing an ultra-high strength steel plate having a microstructure comprising predominantly tempered fine-grained lath martensite, tempered fine-grained lower bainite, or mixtures thereof, wherein the method comprises the steps of (a) heating a steel slab to a reheating temperature sufficiently high to (i) substantially homogenize the steel slab, (ii) dissolve substantially all carbides and carbonitrides of niobium and vanadium in the steel slab, and (iii) establish fine initial austenite grains in the steel slab; (b) reducing the steel slab to form steel plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; (c) further reducing the steel plate in one or more hot rolling passes in a second temperature range below about the Tnr temperature and above about the Ar3 transformation temperature; (d) quenching the steel plate at a cooling rate of about 10� C. per second to about 40� C. per second (18� F./sec -72� F./sec) to a Quench Stop Temperature below about the Ms transformation temperature plus 200� C. (360� F.); (e) stopping the quenching; and (f) tempering the steel plate at a tempering temperature from about 400� C. (752� F.) up to about the Ac1 transformation temperature, preferably up to, but not including, the Ac1 transformation temperature, for a period of time sufficient to cause precipitation of hardening particles, i.e., one or more of ε-copper, Mo2C, or the carbides and carbonitrides of niobium and vanadium. The period of time sufficient to cause precipitation of hardening particles depends primarily on the thickness of the steel plate, the chemistry of the steel plate, and the tempering temperature, and can be determined by one skilled in the art. (See Glossary for definitions of predominantly, of hardening particles, of Tnr temperature, of Ar3, Ms, and Ac1 transformation temperatures, and of Mo2C).
To ensure ambient and cryogenic temperature toughness, steels according to this first steel example preferably have a microstructure comprised of predominantly tempered fine-grained lower bainite, tempered fine-grained lath martensite, or mixtures thereof. It is preferable to substantially minimize the formation of embrittling constituents such as upper bainite, twinned martensite and MA. As used in this first steel example, and in the claims, �predominantly� means at least about 50 volume percent. More preferably, the microstructure comprises at least about 60 volume percent to about 80 volume percent tempered fine-grained lower bainite, tempered fine-grained lath martensite, or mixtures thereof. Even more preferably, the microstructure comprises at least about 90 volume percent tempered fine-grained lower bainite, tempered fine-grained lath martensite, or mixtures thereof. Most preferably, the microstructure comprises substantially 100% tempered fine-grained lath martensite.
0.04-0.12,
more preferably 0.04-0.07
more preferably 1.0 1.8
more preferably 1.5-2.5
0.1-1.5,
more preferably 0.5-1.0
0.1-0.8,
0.02-0.1,
more preferably 0.03-0.05
0.008-0.03,
more preferably 0.01-0.02
0.001-0.05,
more preferably 0.005-0.03
0.002-0.005,
more preferably 0.002-0.003
The thus direct quenched martensite in steels according to this first steel example has ultra-high strength but its toughness can be improved by tempering at a suitable temperature from above about 400� C. (752� F.) up to about the Ac1 transformation temperature. Tempering of steel within this temperature range also leads to reduction of the quenching stresses which in turn leads to enhanced toughness. While tempering can enhance the toughness of the steel, it normally leads to substantial loss of strength. In the present invention, the usual strength loss from tempering is offset by inducing precipitate dispersion hardening. Dispersion hardening from fine copper precipitates and mixed carbides and/or carbonitrides are utilized to optimize strength and toughness during the tempering of the martensitic structure. The unique chemistry of the steels of this first steel example allows for tempering within the broad range of about 400� C. to about 650� C. (750� F.-1200� F.) without any significant loss of the as-quenched strength. The steel plate is preferably tempered at a tempering temperature from above about 400� C. (752� F.) to below the Ac1 transformation temperature for a period of time sufficient to cause precipitation of hardening particles (as defined herein). This processing facilitates transformation of the microstructure of the steel plate to predominantly tempered fine-grained lath martensite, tempered fine-grained lower bainite, or mixtures thereof. Again, the period of time sufficient to cause precipitation of hardening particles depends primarily on the thickness of the steel plate, the chemistry of the steel plate, and the tempering temperature, and can be determined by one skilled in the art.
As discussed above, a copending U.S. patent application, having a priority date of Dec. 19, 1997, entitled �Ultra-High Strength Ausaged Steels With Excellent Cryogenic Temperature Toughness�, and identified by the USPTO as Application No. 09/099,153 and has been published in WO 99/32670, provides a description of other steels suitable for use in the present invention. A method is provided for preparing an ultra-high strength steel plate having a micro-laminate microstructure comprising about 2 vol % to about 10 vol % austenite film layers and about 90 vol % to about 98 vol % laths of predominantly fine-grained martensite and fine-grained lower bainite, said method comprising the steps of: (a) heating a steel slab to a reheating temperature sufficiently high to (i) substantially homogenize the steel slab, (ii) dissolve substantially all carbides and carbonitrides of niobium and vanadium in the steel slab, and (iii) establish fine initial austenite grains in the steel slab; (b) reducing the steel slab to form steel plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; (c) further reducing the steel plate in one or more hot rolling passes in a second temperature range below about the Tnr temperature and above about the Ar3 transformation temperature; (d) quenching the steel plate at a cooling rate of about 10� C. per second to about 40� C. per second (18� F./sec-72� F./sec) to a Quench Stop Temperature (QST) below about the Ms transformation temperature plus 100� C. (180� F.) and above about the Ms transformation temperature; and (e) stopping said quenching. In one embodiment, the method of this second steel example further comprises the step of allowing the steel plate to air cool to ambient temperature from the QST. In another embodiment, the method of this second steel example further comprises the step of holding the steel plate substantially isothermally at the QST for up to about 5 minutes prior to allowing the steel plate to air cool to ambient temperature. In yet another embodiment, the method of this second steel example further comprises the step of slow-cooling the steel plate from the QST at a rate lower than about 1.0� C. per second (1.8� F./sec) for up to about 5 minutes prior to allowing the steel plate to air cool to ambient temperature. In yet another embodiment, the method of this invention further comprises the step of slow-cooling the steel plate from the QST at a rate lower than about 1.0� C. per second (1.8� F./sec) for up to about 5 minutes prior to allowing the steel plate to air cool to ambient temperature. This processing facilitates transformation of the microstructure of the steel plate to about 2 vol % to about 10 vol % of austenite film layers and about 90 vol % to about 98 vol % laths of predominantly fine-grained martensite and fine-grained lower bainite. (See Glossary for definitions of Tnr temperature, and of Ar3 and Ms transformation temperatures.)
To ensure ambient and cryogenic temperature toughness, the laths in the micro-laminate microstructure preferably comprise predominantly lower bainite or martensite. It is preferable to substantially minimize the formation of embrittling constituents such as upper bainite, twinned martensite and MA. As used in this second steel example, and in the claims, �predominantly� means at least about 50 volume percent. The remainder of the microstructure can comprise additional fine-grained lower bainite, additional fine-grained lath martensite, or ferrite. More preferably, the microstructure comprises at least about 60 volume percent to about 80 volume percent lower bainite or lath martensite. Even more preferably, the microstructure comprises at least about 90 volume percent lower bainite or lath martensite.
more preferably 1.0-1.8
0.1-1.0,
more preferably 0.02-0.05
As discussed above, a copending U.S. patent application, having a priority date of Dec. 19, 1997, entitled �Ultra-High Strength Dual Phase Steels With Excellent Cryogenic Temperature Toughness�, and identified by the USPTO as Application No. 09/099,152 and has been published in WO 99/32671, provides a description of other steels suitable for use in the present invention. A method is provided for preparing an ultra-high strength, dual phase steel plate having a microstructure comprising about 10 vol % to about 40 vol % of a first phase of substantially 100 vol % (i.e., substantially pure or �essentially�) ferrite and about 60 vol % to about 90 vol % of a second phase of predominantly fine-grained lath martensite, fine-grained lower bainite, or mixtures thereof, wherein the method comprises the steps of (a) heating a steel slab to a reheating temperature sufficiently high to (i) substantially homogenize the steel slab, (ii) dissolve substantially all carbides and carbonitrides of niobium and vanadium in the steel slab, and (iii) establish fine initial austenite grains in the steel slab; (b) reducing the steel slab to form steel plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; (c) further reducing the steel plate in one or more hot rolling passes in a second temperature range below about the Tnr temperature and above about the Ar3 transformation temperature; (d) further reducing said steel plate in one or more hot rolling passes in a third temperature range below about the Ar3 transformation temperature and above about the Ar1 transformation temperature (i.e., the intercritical temperature range); (e) quenching said steel plate at a cooling rate of about 10� C. per second to about 40� C. per second (18� F./sec-72� F./sec) to a Quench Stop Temperature (QST) preferably below about the Ms transformation temperature plus 200� C. (360� F.); and (f) stopping said quenching. In another embodiment of this third steel example, the QST is preferably below about the Ms transformation temperature plus 100� C. (180� F.), and is more preferably below about 350� C. (662� F.). In one embodiment of this third steel example, the steel plate is allowed to air cool to ambient temperature after step (f). This processing facilitates transformation of the microstructure of the steel plate to about 10 vol % to about 40 vol % of a first phase of ferrite and about 60 vol % to about 90 vol % of a second phase of predominantly fine-grained lath martensite, fine-grained lower bainite, or mixtures thereof. (See Glossary for definitions of Tnr temperature, and of Ar3 and Ar1 transformation temperatures).
To ensure ambient and cryogenic temperature toughness, the microstructure of the second phase in steels of this third steel example comprises predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof. It is preferable to substantially minimize the formation of embrittling constituents such as upper bainite, twinned martensite and MA in the second phase. As used in this third steel example, and in the claims, �predominantly� means at least about 50 volume percent. The remainder of the second phase microstructure can comprise additional fine-grained lower bainite, additional fine-grained lath martensite, or ferrite. More preferably, the microstructure of the second phase comprises at least about 60 volume percent to about 80 volume percent fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof. Even more preferably, the microstructure of the second phase comprises at least about 90 volume percent fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof.
Other suitable steels for use in connection with the present invention are described in other publications that describe ultra-high strength, low alloy steels containing less than about 1 wt % nickel, having tensile strengths greater than 830 MPa (120 ksi), and having excellent low-temperature toughness. For example, such steels are described in a European Patent Application published Feb. 5, 1997, and having International application number: PCT/JP96/00157, and International publication number WO 96/23909 (08.08.1996 Gazette 1996/36) (such steels preferably having a copper content of 0.1 wt % to 1.2 wt %), and in a pending U.S. patent application with a priority date of Jul. 28, 1997, entitled �Ultra-High Strength, Weldable Steels with Excellent Ultra-Low Temperature Toughness�, and identified by the USPTO as Application No. 09/123,625 and has been published in WO 99/05335.
For any of the above-referenced steels, as is understood by those skilled in the art, as used herein �percent reduction in thickness� refers to percent reduction in the thickness of the steel slab or plate prior to the reduction referenced. For purposes of explanation only, without thereby limiting this invention, a steel slab of about 25.4 cm (10 inches) thickness may be reduced about 50% (a 50 percent reduction), in a first temperature range, to a thickness of about 12.7 cm (5 inches) then reduced about 80% (an 80 percent reduction), in a second temperature range, to a thickness of about 2.5 cm (1 inch). Again, for purposes of explanation only, without thereby limiting this invention, a steel slab of about 25.4 cm (10 inches) may be reduced about 30% (a 30 percent reduction), in a first temperature range, to a thickness of about 17.8 cm (7 inches) then reduced about 80% (an 80 percent reduction), in a second temperature range, to a thickness of about 3.6 cm (1.4 inch), and then reduced about 30% (a 30 percent reduction), in a third temperature range, to a thickness of about 2.5 cm (1 inch). As used herein, �slab� means a piece of steel having any dimensions.
When a dual phase steel is used in the construction of process components, containers, and pipes according to this invention, the dual phase steel is preferably processed in such a manner that the time period during which the steel is maintained in the intercritical temperature range for the purpose of creating the dual phase structure occurs before the accelerated cooling or quenching step. Preferably the processing is such that the dual phase structure is formed during cooling of the steel between the Ar3 transformation temperature to about the Ar1 transformation temperature. An additional preference for steels used in the construction of process components, containers, and pipes according to this invention is that the steel has a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about −73� C. (−100� F.) upon completion of the accelerated cooling or quenching step, i.e., without any additional processing that requires reheating of the steel such as tempering. More preferably the tensile strength of the steel upon completion of the quenching or cooling step is greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). In some applications, a steel having a tensile strength of greater than about 930 MPa (135 ksi), or greater than about 965 MPa (140 ksi), or greater than about 1000 MPa (145 ksi), upon completion of the quenching or cooling step is preferable.
Process components, containers, and pipes constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.) are provided. Preferably the ultra-high strength, low alloy steel contains less than about 7 wt % nickel, and more preferably contains less than about 5 wt % nickel. Preferably the ultra-high strength, low alloy steel has a tensile strength greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). Even more preferably, the process components, containers, and pipes of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.).
The process components, containers, and pipes of this invention are preferably constructed from discrete plates of ultra-high strength, low alloy steel with excellent cryogenic temperature toughness. The joints or seams of the components, containers, and pipes preferably have about the same strength and toughness as the ultra-high strength, low alloy steel plates. In some cases, an undermatching of the strength on the order of about 5% to about 10% may be justified for locations of lower stress. Joints or seams with the preferred properties can be made by any suitable joining technique. An exemplary joining technique is described herein, under the subheading �Joining Methods for Construction of Process Components, Containers, and Pipes�.
As will be familiar to those skilled in the art, the Charpy V-notch (CVN) test can be used for the purpose of fracture toughness assessment and fracture control in the design of process components, containers, and pipes for processing and transporting pressurized, cryogenic temperature fluids, particularly through use of the ductile-to-brittle transition temperature (DBTT). The DBTT delineates two fracture regimes in structural steels. At temperatures below the DBTT, failure in the Charpy V-notch test tends to occur by low energy cleavage (brittle) fracture, while at temperatures above the DBTT, failure tends to occur by high energy ductile fracture. Containers that are constructed from welded steels for the load-bearing, cryogenic temperature service must have DBTTs, as determined by the Charpy V-notch test, well below the service temperature of the structure in order to avoid brittle failure. Depending on the design, the service conditions, and/or the requirements of the applicable classification society, the required DBTT temperature shift may be from 5� C. to 30� C. (9� F. to 54� F.) below the service temperature.
As will be familiar to those skilled in the art, the operating conditions taken into consideration in the design of storage containers constructed from a welded steel for transporting pressurized, cryogenic fluids, include among other things, the operating pressure and temperature, as well as additional stresses that are likely to be imposed on the steel and the weldments (see Glossary). Standard fracture mechanics measurements, such as (i) critical stress intensity factor (KIC), which is a measurement of plane-strain fracture toughness, and (ii) crack tip opening displacement (CTOD), which can be used to measure elastic-plastic fracture toughness, both of which are familiar to those skilled in the art, may be used to determine the fracture toughness of the steel and the weldments. Industry codes generally acceptable for steel structure design, for example, as presented in the BSI publication �Guidance on methods for assessing the acceptability of flaws in fusion welded structures�, often referred to as �PD 6493:1991�, may be used to determine the maximum allowable flaw sizes for the containers based on the fracture toughness of the steel and weldment (including HAZ) and the imposed stresses on the container. A person skilled in the art can develop a fracture control program to mitigate fracture initiation through (i) appropriate container design to minimize imposed stresses, (ii) appropriate manufacturing quality control to minimize defects, (iii) appropriate control of life cycle loads and pressures applied to the container, and (iv) an appropriate inspection program to reliably detect flaws and defects in the container. A preferred design philosophy for the system of the present invention is �leak before failure�, as is familiar to those skilled in the art. These considerations are generally referred to herein as �known principles of fracture mechanics.�
For process components, containers, and pipes that require bending of the steel, e.g., into a cylindrical shape for a container or into a tubular shape for a pipe, the steel is preferably bent into the desired shape at ambient temperature in order to avoid detrimentally affecting the excellent cryogenic temperature toughness of the steel. If the steel must be heated to achieve the desired shape after bending, the steel is preferably heated to a temperature no higher than about 600� C. (1112� F.) in order to preserve the beneficial effects of the steel microstructure as described above.
Process components constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.) are provided. Preferably the ultra-high strength, low alloy steel contains less than about 7 wt % nickel, and more preferably contains less than about 5 wt % nickel. Preferably the ultra-high strength, low alloy steel has a tensile strength greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). Even more preferably, the process components of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.). Such process components are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein.
In Fixed Tubesheet Example Nos. 1-4, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 preferably are constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of fixed tubesheet, single pass heat exchanger system 20 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
In a first example, kettle reboiler heat exchanger system 30 is used in a cryogenic gas liquids recovery plant with propane vaporizing at about −40� C. (−40� F.) on the kettle side and hydrocarbon gas on the tubeside. The hydrocarbon gas enters kettle reboiler heat exchanger system 30 through tubeside inlet 34 and exits through tubeside outlet 35, while the propane enters through kettle inlet 36 and exits through kettle outlet 37.
In a second example, kettle reboiler heat exchanger system 30 is used in a refrigerated lean oil plant with propane vaporizing at about −40� C. (−40� F.) on the kettle side and lean oil on the tubeside. The lean oil enters kettle reboiler heat exchanger system 30 through tube inlet 34 and exits through tube outlet 35, while the propane enters through kettle inlet 36 and exits through kettle outlet 37.
In another example, kettle reboiler heat exchanger system 30 is used in a Ryan Holmes product recovery column with propane vaporizing at about −40� C. (−40� F.) on the kettle side and product recovery column overhead gas on the tubeside to condense reflux for the tower. The product recovery column overhead gas enters kettle reboiler heat exchanger system 30 through tube inlet 34 and exits through tube outlet 35, while the propane enters through kettle inlet 36 and exits through kettle outlet 37.
In Kettle Reboiler Example Nos. 1-7, kettle reboiler body 31, heat exchanger tube 33, weir 32, and port connections for tubeside inlet 34, tubeside outlet 35, kettle inlet 36, and kettle outlet 37 preferably are constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, kettle reboiler body 31, heat exchanger tube 33, weir 32, and port connections for tubeside inlet 34, tubeside outlet 35, kettle inlet 36, and kettle outlet 37 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of kettle reboiler heat exchanger system 30 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
Referring to FIG. 1, a condenser according to this invention is used in a demethanizer gas plant 10 in which a feed gas stream is separated into a residue gas and a product stream using a demethanizer column 11. In this particular example, the overhead from demethanizer column 11, at a temperature of about −90� C. (−130� F.) is condensed into a reflux accumulator (separator) 15 using reflux condenser system 12. Reflux condenser system 12 exchanges heat with the gaseous discharge stream from expander 13. Reflux condenser system 12 is primarily a heat exchanger system, preferably of the types discussed above. In particular, reflux condenser system 12 may be a fixed tubesheet, single pass heat exchanger (e.g. fixed tubesheet, single pass heat exchanger 20, as illustrated by FIG. 2 and described above). Referring again to FIG. 2, the discharge stream from expander 13 enters fixed tubesheet, single pass heat exchanger system 20 through tube inlet 26 and exits through tube outlet 27 while the demethanizer overhead enters the shell inlet 28 and exits through shell outlet 29.
Referring again to FIG. 2, in Condenser Example Nos. 1 and 2, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 preferably are constructed from ultra-high strength, low alloy steels containing less than about 3 wt % nickel and have adequate strength and cryogenic temperature fracture toughness to contain the cryogenic fluid being processed, and more preferably are constructed from ultra-high strength, low alloy steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of condenser system 70 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
Referring now to FIG. 8, a condenser according to this invention is used in a cascade refrigeration cycle 80 consisting of several staged compression cycles. The major items of equipment of cascade refrigeration cycle 80 include propane compressor 81, propane condenser 82, ethylene compressor 83, ethylene condenser 84, methane compressor 85, methane condenser 86, methane evaporator 87, and expansion valves 88. Each stage operates at successively lower temperatures by the selection of a series of refrigerants with boiling points that span the temperature range required for the complete refrigeration cycle. In this example cascade cycle, the three refrigerants, propane, ethylene, and methane, may be used in an LNG process with the typical temperatures indicated on FIG. 8. In this example, all parts of methane condenser 86 and of ethylene condenser 84 preferably are constructed from ultra-high strength, low alloy steels containing less than about 3 wt % nickel and have adequate strength and cryogenic temperature fracture toughness to contain the cryogenic fluid being processed, and more preferably are constructed from ultra-high strength, low alloy steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, all parts of methane condenser 86 and of ethylene condenser 84 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of cascade refrigeration cycle 80 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
In a first example, a vaporizer system according to this invention is used in a reverse Rankine cycle for generating power using the cold energy from a cold energy source such as pressurized LNG (as defined herein) or conventional LNG (as defined herein). In this particular example, a process stream of PLNG from a transportation storage container is completely vaporized using the vaporizer. The heating medium may be power fluid used in a closed thermodynamic cycle, such as a reverse Rankine cycle, to generate power. Alternatively, the heating medium may consist of a single fluid used in an open loop to completely vaporize the PLNG, or several different fluids with successively higher freezing points used to vaporize and successively warm the PLNG to ambient temperature. In all cases, the vaporizer serves the function of a heat exchanger, preferably of the types described in detail herein under the subheading �Heat Exchangers�. The mode of application of the vaporizer and the composition and properties of the stream or streams processed determine the specific type of heat exchanger required. As an example, referring again to FIG. 2, where use of fixed tubesheet, single pass heat exchanger system 20 is applicable, a process stream, such as PLNG, enters fixed tubesheet single pass heat exchanger system 20 through tube inlet 26 and exits through tube outlet 27, while the heating medium enters through shell inlet 28 and exits through shell outlet 29. In this example, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 preferably are constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, heat exchanger body 20 a, channel covers 21 a and 21 b, tubesheet 22, vent 23, and baffles 24 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of fixed tubesheet, single pass heat exchanger system 20 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
In another example, a vaporizer according to this invention is used in a cascade refrigeration cycle consisting of several staged compression cycles, as illustrated by FIG. 9. Referring to FIG. 9, each of the two staged compression cycles of cascade cycle 90 operates at successively lower temperatures by the selection of a series of refrigerants with boiling points that span the temperature range required for the complete refrigeration cycle. The major items of equipment in cascade cycle 90 include propane compressor 92, propane condenser 93, ethylene compressor 94, ethylene condenser 95, ethylene evaporator 96, and expansion valves 97. In this example, the two refrigerants propane and ethylene are used in a PLNG liquefaction process with the typical temperatures indicated. Ethylene evaporator 96 preferably is constructed from steels containing less than about 3 wt % nickel and has adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably is constructed from steels containing less than about 3 wt % nickel and has a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.). Furthermore, ethylene evaporator 96 is preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of cascade cycle 90 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
Separators, or separator systems, (i) constructed from ultra-high strength, low alloy steels containing less than about 3 wt % nickel and (ii) having adequate strength and cryogenic temperature fracture toughness to contain cryogenic temperature fluids, are provided. More particularly, separator systems, with at least one component (i) constructed from an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and (ii) having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.), are provided. Components of such separator systems are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Without thereby limiting this invention, the following example illustrates a separator system according to this invention.
FIG. 4 illustrates a separator system 40 according to the present invention. In one embodiment, separator system 40 includes vessel 41, inlet port 42, liquid outlet port 43, gas outlet 44, support skirt 45, liquid level controller 46, isolation baffle 47, mist extractor 48, and pressure relief valve 49. In one example application, without thereby limiting this invention, separator system 40 according to the present invention is advantageously utilized as an expander feed separator in a cryogenic gas plant to remove condensed liquids upstream of an expander. In this example, vessel 41, inlet port 42, liquid outlet port 43, support skirt 45, mist extractor supports 48, and isolation baffle 47 are preferably constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, vessel 41, inlet port 42, liquid outlet port 43, support skirt 45, mist extractor supports 48, and isolation baffle 47 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of separator system 40 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
FIG. 11 illustrates a process column system according to the present invention. In this embodiment, demethanizer process column system 110 includes column 111, separator bell 112, first inlet 113, second inlet 114, liquid outlet 121, vapor outlet 115, reboiler 119, and packing 120. In one example application, without thereby limiting this invention, process column system 110 according to the present invention is advantageously utilized as a demethanizer in a cryogenic gas plant to separate methane from the other condensed hydrocarbons. In this example, column 111, separator bell 112, packing 120, and other internals commonly used in such a process column system 110 are preferably constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, column 111, separator bell 112, packing 120, and other internals commonly used in such a process column system 110 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of process column system 110 may also be constructed from ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
FIG. 12 illustrates a process column system 125 according to the present invention. In this example, process column system 125 is advantageously utilized as a CFZ tower in a CFZ process for separating CO2 from methane. In this example, column 126, melting trays 127, and contacting trays 128 are preferably constructed from steels containing less than about 3 wt % nickel and have adequate strength and fracture toughness to contain the cryogenic temperature fluid being processed, and more preferably are constructed from steels containing less than about 3 wt % nickel and have tensile strengths exceeding about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, column 126, melting trays 127, and contacting trays 128 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of process column system 125 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
Referring now to FIG. 10, pump system 100 is constructed according to this invention. Pump system 100 is made from substantially cylindrical and plate components. A cryogenic fluid enters cylindrical fluid inlet 101 from a pipe attached to inlet flange 102. The cryogenic fluid flows inside cylindrical casing 103 to pump inlet 104 and into multi-stage pump 105 where it undergoes an increase in pressure energy. Multi-stage pump 105 and drive shaft 106 are supported by a cylindrical bearing and pump support housing (not shown in FIG. 10). The cryogenic fluid leaves pump system 100 through fluid outlet 108 in a pipe attached to fluid exit flange 109. A driving means such as an electric motor (not shown in FIG. 10) is mounted on the drive mounting flange 210 and attached to pump system 100 through drive coupling 211. Drive mounting flange 210 is supported by cylindrical coupling housing 212. In this example, pump system 100 is mounted between pipe flanges (not shown in FIG. 10); but other mounting systems are also applicable, such as submerging pump system 100 in a tank or vessel such that the cryogenic liquid enters directly into fluid inlet 101 without the connecting pipe. Alternatively, pump system 100 is installed in another housing or �pump pot�, where both fluid inlet 101 and fluid outlet 108 are connected to the pump pot, and pump system 100 is readily removable for maintenance or repair. In this example, pump casing 213, inlet flange 102, drive coupling housing 212, drive mounting flange 210, mounting flange 214, pump end plate 215, and pump and bearing support housing 217 are all preferably constructed from steels containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.), and more preferably are constructed from steels containing less than about 3 wt % nickel and having tensile strengths greater than about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, pump casing 213, inlet flange 102, drive coupling housing 212, drive mounting flange 210, mounting flange 214, pump end plate 215, and pump and bearing support housing 217 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of pump system 100 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
FIG. 5 illustrates a flare system 50 according to the present invention. In one embodiment, flare system 50 includes blowdown valves 56, piping, such as lateral line 53, collection header line 52, and flare line 51, and also includes a flare scrubber 54, a flare stack or boom 55, a liquid drain line 57, a drain pump 58, a drain valve 59, and auxiliaries (not shown in FIG. 5) such as ignitors and purge gas. Flare system 50 typically handles combustible fluids that are at cryogenic temperatures due to process conditions or that cool to cryogenic temperatures upon relief to flare system 50, i.e., from a large pressure drop across relief valves or blowdown valves 56. Flare line 51, collection header line 52, lateral line 53, flare scrubber 54, and any additional associated piping or systems that would be exposed to the same cryogenic temperatures as flare system 50 are all preferably constructed from steels containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.), and more preferably are constructed from steels containing less than about 3 wt % nickel and having tensile strengths greater than about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, flare line 51, collection header line 52, lateral line 53, flare scrubber 54, and any additional associated piping or systems that would be exposed to the same cryogenic temperatures as flare system 50 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of flare system 50 may also be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein, or from other suitable materials.
Containers constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.) are provided. Preferably the ultra-high strength, low alloy steel contains less than about 7 wt % nickel, and more preferably contains less than about 5 wt % nickel. Preferably the ultra-high strength, low alloy steel has a tensile strength greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). Even more preferably, the containers of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.). Such containers are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein.
Flowline distribution network systems, comprising pipes constructed from materials comprising an ultra-high strength, low alloy steel containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.) are provided. Preferably the ultra-high strength, low alloy steel contains less than about 7 wt % nickel, and more preferably contains less than about 5 wt % nickel. Preferably the ultra-high strength, low alloy steel has a tensile strength greater than about 860 MPa (125 ksi), and more preferably greater than about 900 MPa (130 ksi). Even more preferably, the flowline distribution network system pipes of this invention are constructed from materials comprising an ultra-high strength, low alloy steel containing less than about 3 wt % nickel and having a tensile strength exceeding about 1000 MPa (145 ksi) and a DBTT lower than about −73� C. (−100� F.). Such pipes are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. FIG. 6 illustrates a flowline distribution network system 60 according to the present invention. In one embodiment, flowline distribution network system 60 includes piping, such as primary distribution pipes 61, secondary distribution pipes 62, and tertiary distribution pipes 63, and includes main storage containers 64, and end use storage containers 65. Main storage containers 64 and end use storage containers 65 are all designed for cryogenic service, i.e., appropriate insulation is provided. Any appropriate insulation type may be used, for example, without thereby limiting this invention, high-vacuum insulation, expanded foam, gas-filled powders and fibrous materials, evacuated powders, or multi-layer insulation. Selection of an appropriate insulation depends on performance requirements, as is familiar to those skilled in the art of cryogenic engineering. Main storage containers 64, piping, such as primary distribution pipes 61, secondary distribution pipes 62, and tertiary distribution pipes 63, and end use storage containers 65 are preferably constructed from steels containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73� C. (−100� F.), and more preferably are constructed from steels containing less than about 3 wt % nickel and having tensile strengths greater than about 1000 MPa (145 ksi) and DBTTs lower than about −73� C. (−100� F.). Furthermore, main storage containers 64, piping, such as primary distribution pipes 61, secondary distribution pipes 62, and tertiary distribution pipes 63, and end use storage containers 65 are preferably constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein. Other components of distribution network system 60 may be constructed from the ultra-high strength, low alloy steels with excellent cryogenic temperature toughness described herein or from other suitable materials.
Ar1 transformation
controlled freeze zone;
conventional LNG:
liquefied natural gas at about atmospheric
pressure and about −162� C. (−260� F.);
one or more of ε-copper, Mo2C, or the carbides
from about the Ac1 transformation temperature
to about the Ac3 transformation temperature on
a steel containing iron and less than about 10 wt
pressurized liquefied
liquefied natural gas at a pressure of about 1035
natural gas (PLNG):
kPa (150 psia) to about 7590 kPa (1100 psia)
and at a temperature of about −123� C. (−190� F.)
to about −62� C. (−80� F.);
parts-per-million;
accelerated cooling by any means whereby a fluid
Temperature (QST):
a welded joint, including: (i) the weld metal, (ii)
metal in the �near vicinity� of the HAZ. The
within the �near vicinity� of the HAZ, and
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Ladkany, "Composite Aluminum-Fiberglass Epoxy Pressure Vessels for Transportation of LNG at Intermediate Temperature", published in Advances in Cryogenic Engineering, Materials, vol. 28, (Proceedings of the 4th International Cryogenic Materials Conference), San Diego, CA, USA, Aug. 10-14, 1981, pp. 905-913.** Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6843237Nov 25, 2002Jan 18, 2005Exxonmobil Upstream Research CompanyCNG fuel storage and delivery systems for natural gas powered vehiclesUS6852175Nov 25, 2002Feb 8, 2005Exxonmobil Upstream Research CompanyHigh strength marine structuresUS7386996 *Mar 15, 2001Jun 17, 2008Den Norske Stats Oljeselskap A.S.Natural gas liquefaction processUS7591150May 15, 2006Sep 22, 2009Battelle Energy Alliance, LlcApparatus for the liquefaction of natural gas and methods relating to sameUS8365776May 27, 2010Feb 5, 2013Conocophillips CompanyLiquefied natural gas pipeline with near zero coefficient of thermal expansionUS8567485Sep 23, 2005Oct 29, 2013Ti Group Automotive Systems LimitedHeat exchanger for connection to an evaporator of a heat transfer systemUS8763411Jun 15, 2011Jul 1, 2014Biofilm Ip, LlcMethods, devices and systems for extraction of thermal energy from a heat conducting metal conduitUS8820615 *Jul 10, 2009Sep 2, 2014Aktiebolaget SkfMethod for manufacturing a steel component, a weld seam, a welded steel component, and a bearing componentUS20110158572 *Jul 10, 2009Jun 30, 2011Patrik DahlmanMethod for Manufacturing a Steel Component, A Weld Seam, A Welded Steel Component, and a Bearing ComponentUS20120017639 *Jun 16, 2011Jan 26, 2012Synfuels International, Inc.Methods and systems for storing and transporting gasesEP1478874A1 *Jul 1, 2002Nov 24, 2004Bechtel BWXT Idaho, LLCApparatus for the liquefaction of natural gas and methods relating to sameWO2007056241A2 *Nov 4, 2006May 18, 2007Mev Technology IncDual thermodynamic cycle cryogenically fueled systemsWO2011159355A2Jun 15, 2011Dec 22, 2011Biofilm Ip, LlcMethods, devices systems for extraction of thermal energy from a heat conducting metal conduitWO2014086413A1Dec 5, 2012Jun 12, 2014Blue Wave Co S.A.Integrated and improved system for sea transportation of compressed natural gas in vessels, including multiple treatment steps for lowering the temperature of the combined cooling and chilling type* Cited by examinerClassifications U.S. Classification62/50.7, 148/336, 62/905, 220/749, 420/92International ClassificationF17C1/00, C22C38/00, C22C38/42, F04B23/02, F28D7/06, F28F21/08, F25J1/02, F25J1/00, C22C38/40, F17C9/02, F25B19/00, C22C38/08, C21D6/00, F17C13/00, F28F9/22, F04D29/02, C22C38/12, F17C1/14, C22C38/04, F25J3/00, F17C7/02, C21D1/18, F25J3/02, C22C38/16Cooperative ClassificationY10S62/905, F17C2203/0345, C22C38/12, F17C2201/0138, F17C2223/0161, F25J2235/02, F25J3/0238, C21D2211/002, F17C2203/0648, F25J2240/02, F17C2221/014, F25J3/04896, F17C2221/016, F17C2203/0391, F17C2270/0136, F25J3/04866, F17C2223/033, F17C2221/018, F17C2265/068, F17C2270/0105, F17C2201/032, F17C2221/033, F17C2265/063, F25J2205/04, F25J1/0257, F28D2021/0033, F05C2201/0448, C22C38/16, F17C2221/017, F04D29/026, F25J5/002, F25J1/0204, F25J2290/44, F04B23/021, F17C1/14, F17C2209/221, F17C13/00, F17C2201/052, F25J3/0209, C21D1/18, F17C7/02, F28D7/06, C21D2211/008, F17C2270/01, F17C2260/011, F17C2270/05, F17C2201/054, C22C38/08, F25J3/0233, F25J2200/74, F25J1/0262, F17C2221/013, F17C2203/0329, C22C38/04, F25J3/0295, F25J1/0207, F17C2203/0639, C22C38/40, F17C2221/011, C22C38/42, F25J2205/02, F17C2201/056, F17C2203/0337, F28F9/22, F25J1/0268, C21D6/001, F28F21/082, F25J2200/02, F25J1/0022, F17C2201/0104, F17C2203/0617, F25J2290/42, F25J5/005European ClassificationF25J1/02Z4H, F25J1/02Z4H4R4, F25J1/02Z4, F25J3/04Z4C, F25J3/04Z4, F25J1/02B2, F25J1/00A6, F25J5/00B, F28F21/08A2, F04B23/02B, F28D7/06, C22C38/40, C22C38/42, F25J1/02B6, C22C38/04, F17C1/14, F17C13/00, F25J3/02C4, C22C38/08, F17C7/02, F04D29/02P, C22C38/16, F25J3/02C2, C22C38/12, F28F9/22, F25J3/02A2, F25J3/02ZLegal EventsDateCodeEventDescriptionMay 28, 2013FPExpired due to failure to pay maintenance feeEffective date: 20130410Apr 10, 2013LAPSLapse for failure to pay maintenance feesNov 19, 2012REMIMaintenance fee reminder mailedSep 18, 2008FPAYFee paymentYear of fee payment: 8Sep 29, 2004FPAYFee paymentYear of fee payment: 4Mar 1, 2000ASAssignmentOwner name: EXXONMOBIL UPSTREAM RESEARCH COMPANY, TEXASFree format text: CHANGE OF NAME;ASSIGNOR:EXXON PRODUCTION RESEARCH COMPANY;REEL/FRAME:010655/0108Effective date: 19991209Owner name: EXXONMOBIL UPSTREAM RESEARCH COMPANY P.O. 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