Request A Quote

Video Category: Expansion Joints Info

Video Category: Fabric Expansion Joints

U.S Bellows Quick Turnaround Refurbishing Of Failed Bellows

Need it quickly? Here at PT&P our standard emergency orders is within

24 hours. Beyond our fast and custom quote turnaround and dependability

There are a number of ways we stand out in the industry, all wrapped around

two things: Our commitment to customers & our goal to provide a quality 

product in a timely manner. 

Single Flanged Expansion Joints for a Leading Manufacturer & Designer of Transformers & Power Supplies for an Industrial Applications Company

U.s. bellows custom designed single fanged expansion joints for a leading manufacturer & designer of transformers & power supplies for an industrial applications company

Type: Single Flanged Expansion Joint
Size: 5″ Length | 6″ ID | 11″ O.D.
Material: ASTM A240-316 Stainless Steel
Design 200°F | 150 psig | 7,942 lb/in. Lateral Spring Rate
0.625 ” Axial Travel | 803 lb/in. Axial Spring Rate
0.125″ Lateral Offset | 225 psig Test Pressure
Testing: 100% Dye-Penetrant | Air, Soap, & Bubble

These units were sold to a company that manufactures customized power conversion solutions used in power supplies, transformers, inductors and capacitors for industrial and military applications. Expansion joints are used in a wide range of industries from automotive, food processing, biofuels, and wastewater treatment plants. This expansion joint is simply a bellows element with flanged end connections. Regardless of accessories, such as liners and covers, it will deflect in any direction or plane. It is the least expensive type of metal expansion joint but requires that the piping be controlled or guided as to the specified direction of the movements required. This type of expansion joint should not be expected to control the movement of the pipe. If the piping analysis shows that the expansion joint must accept axial compression, then the piping must be guided and constrained so that only that movement will occur. This expansion joint will not resist any deflection other than the resistance of the bellows, which is a function of the spring rate times the deflection amount. It is incapable of resisting the pressure thrust along its axis, which is the product of the pressure times the effective, or cross-sectional, area of the bellows. Large diameter units, even with low pressures, can generate very large axial pressure thrust forces, which must be contained by main and directional anchors. Otherwise, the expansion joint will exceed its designed function.

Piping Technology and its subsidiaries, in this case, US Bellows, prides itself on its long-standing relationships with ALL its customers. We have worked with this client for over 10 years with our first project in the early 2000s. We have been their vendor of choice for almost every expansion joint since then. We believe we must be strategic partners with our clients to understand their technical, delivery, and commercial needs to best move forward. This is where we are different than other key players as we have “in-house” technical and manufacturing expertise in our plant located in Houston, Texas to address customer queries or updates in real-time. An example of what our customers say:

“Thank you very much for the excellent work you and your associates at USB provided on my expansion joint order. Although we agreed to 10-day rush delivery, your shop responded to my project schedule and delivered 14 bellows assemblies in only 7 days from my order. This quick delivery helped us avert a scheduling conflict on a very critical project. I would be glad to recommend U.S. Bellows to anyone in need of a quality product with on-time or better delivery. 2022”

*Designed in accordance with the Standards of the Expansion Joint Manufacturers Association, 10th E, and welding per ASME Boiler and Pressure Vessel Code Section IX.


66″ Diameter Hinged Expansion Joints Designed for a Chemical Plant (PT&P Ref#132483)



Type: Hinged Expansion Joint
Size: 66″ in diameter and 39-3/8″ OAL
Material: Incoloy 825 / 321 stainless steel
Design 73 psig at 986°F with 4.25 degrees of angular rotation
Testing: Dye Penetrant, X-Ray, PMI, Hydrotest

These single hinged expansion joints were custom designed by U.S. Bellows for a chemical plant in Saudi Arabia. The units are 66″ in diameter and 39-3/8″ OAL. The bellows are fabricated from Incoloy 825 with the weld ends, hinges, liner, and cover from 321 stainless steel. The expansion joints are designed for an operating pressure of 73 psig at 986°F with 4.25 degrees of angular rotation. All units were dye-penetrant tested, X-ray tested on all bellows and pipe longitudinal weld seams, PMI tested on all alloy components, and the alloy steel plate for the pipe was ultrasonic tested prior to shipment. Hinged Pipe Expansion Joints also contain hinges or pivots which allow the unit to bend in a single plane. We’ve supplied this type of expansion joint for both methanol and ammonia plants. They are also used in piping systems for Air, Steam, Gas Turbines, Reformer Ducts, and Burners. These units are designed to restrict axial deflection in extension or compression. The hinge mechanism is typically designed to accept full-pressure thrust. Also, because of the hinge mechanism’s design, shear loads, such as from the weight of adjacent piping, can be accepted by this pipe expansion joint, relieving the piping designer of having to provide additional supports and anchors required by the Single type.


Fabric Expansion Joint Designed for a High-Temperature Duct Application

Usbellows fabric expansion joint 170218

Type: Fabric Expansion Joints
Size: 67″ Long x 67″ Wide x 14″ Tall
Material: 3-Layer Fabric Belt with Kaowool Insulation
304 Stainless Steel Angle Flanges
Design Operating Temp: 2012°F at +/- 100″ Water Column
1″ of Lateral Deflection
Testing: 100% Dye Penetrant Testing & Q.C. Inspection

Fabric pipe expansion joints are often used in ducts that carry hot gasses at low pressures. The major design parameters are the temperatures and flow rates of the gasses and the amount and abrasiveness of solids suspended in the gasses. This fabric expansion joint utilizes a bulky flexible material, also called an Insulation Pillow, to shield against high temperatures protecting the belting material. Refractory is also used in the construction of this joint but is designed so that it does not interfere with movement. Our experienced engineers know that every element of this expansion joint plays a role in its rating for certain temperatures and the number of hours of operation. View Fabric Expansion Joints Product Section.
Fabric expansion joints are key in the systems supporting power and refining plants focused around renewable carbon-neutral product offerings. We have worked with the new entrants in the marketplace but also helped our long-term clients transition their older fossil fuel-based assets to green technology. These plants include biochar from biomass processing, carbon black, clean hydrogen, styrene, and cement.


Hinged Expansion Joints Custom-Designed for a Process that Produces High-Density Polyethylene (HDPE)

Hinged Expansion Joints Custom-Designed for a Process that Produces High-Density Polyethylene (HDPE)

U.S. Bellows custom designed these hinged expansion joints for a Polyolefin process which produces High-Density Polyethylene (HDPE) resin at a chemical plant. Polyolefins are a family of polyethylene and polypropylene thermoplastics. The job included expansion joints ranging from 12″ to 32″ NPS. The units pictured above have a nominal pipe size of 16″. The bellows and liner were fabricated from 304 stainless steel and the flanges, cover, and hardware from carbon steel. They are designed for an operating temperature of 176°F at 145 psig and 1° of angular movement. The expansion joints were 100% dye penetrant tested, the bellows longitudinal seam welds were 100% X-rayed, PMI examined, and hydro-tested prior to shipment.


Tied Universal Elbow Expansion Joint Custom-Designed for Ammonia and Waste Processing for a Liquid Nitrogen Fertilizer Plant

Usbellows tied universal expansion joint 143516

Type: Tied Universal Elbow Expansion Joint
Size: 20″ Dia. | 112″ Face-of-Flange to Center Line of Elbow OAL
Material: Inconel® 625 Bellows | 304 H Stainless Steel
Design Operating Temp: 1,150°F at 140 psig | 4″ Lateral Deflection
Testing: Dye Penetrant Examined | 100% X-Rayed Bellows | Hydro-tested

U.S. Bellows, Inc. custom-designed a tied universal elbow expansion joint for ammonia and waste processing for a nitrogen fertilizer plant. The bellows and liner are fabricated from Inconel® 625. The pipe, tie rods, and flanges are fabricated from 304 H stainless steel. It is designed for an operating temperature of 1,150°F at 140 psig and 4″ of lateral deflection. The assembly is 20″ in diameter and 112″ face-of-flange to the centerline of elbow OAL. The unit was 100% x-rayed, dye-penetrate examined, and hydro-tested before shipment.

27″ Dia. Universal Expansion Joints Designed for a Wastewater Treatment Plant

27” Dia. Universal Expansion Joints Designed for a Pipeline in Florida

U.S. Bellows designed universal expansion joints for a wastewater treatment plant in Florida. This was done for a longtime client and market leader in wastewater management, energy services, water, and wastewater treatment. The units are 60″ tall and have a 26.75″ inside diameter. The bellows, cover, liner, and weld-ends are fabricated from 304 stainless steel. They are designed for an operating temperature of 1000°F at 11 psig, with 2″ axial compression and lateral deflection. The units were pneumatically tested at 12 psig prior to shipment. The on-site inspection was done by the client and the EPC firm at our manufacturing facility with our Engineers present to provide any additional clarity that was needed.

U.S. Bellows, EJMA member, is a leader in bellows design and manufacturing. With our manufacturing and engineering both in Houston, we have over 45 years of experience and have deployed over 250k expansion joints which does not include maintenance and repairs services conducted by our highly qualified field service team.

Custom expansion joint design and manufacturing is a complex process and we execute it effectively by focusing on the approval drawings from the customer side, training on customer support with all functional teams (production, engineering, shipping, and sales), and inter-team communication. We developed and deployed digital work instructions for all key production steps and added detailing and reviewing checklists of all of the expansion joint drawings before releasing them to fabrication. These improvements have reduced considerably the number of revisions and reworks. Some insight into jobs we have conducted successfully include:

  • Refurbished 6 48″-64″ Refractory-lined Expansion Joints for a Large Houston Refinery during a 45-day turnaround
  • Completed a large ducting project for a Major Chemical facility in Texas with on-time delivery
  • In the last 6 months, 40% of our expansion joint jobs have shipped in 2 weeks

Usbellows universal expansion joint drawing 159489



Rubber Expansion Joints for an 8” Dia. Pipeline at a Saudi Arabian Oil Company

Ptp rubber expansion joint 171379

U.S. Bellows, Inc. provided rubber expansion joints for an 8″ pipeline. This single open arch rubber expansion joint is fabricated from EPDM rubber and the retaining rings are galvanized A36 carbon steel and powder coated orange. The expansion joints were designed for an operating pressure of 250 psig with a 30″ vacuum, 1.75″ compression, 0.88″ extension, and 1″ lateral offset. Rubber pipe expansion joints are often used to compensate for minor misalignment and offset. Each unit was hydro-tested at 250°F at 75 psig. An advantage of a rubber expansion joint (also called an elastomer joint) over the metallic is the ability to prevent the transmission of vibration and to do this without significant harm to the joint. They can be utilized for pump inlets and discharges solely to stop vibration and noise from the pump. They have an integrally flanged design where no gaskets are required. Metal reinforcing rings can also be added to help resist pressure and flexing during operation. Fabric reinforcement within the rubber can also be added for applications to take the load of fluid pressure. At U.S. Bellows, our engineers are professionally trained and qualified to both design and manufacture units specifically for your application per expansion joint manufacturing association (EJMA).

96″ Dia. Thick Wall Expansion Joint Designed for a Sulfuric Acid Plant

Us bellows thick wall expansion joint 169673

U.S. Bellows designed this thick wall flanged and flued head expansion joint at a sulfuric acid plant in Louisiana.  Sulfuric acid plants are located throughout the industrialized world and we have worked with most of them including market leaders. Most are located near their product acid’s point of use, i.e., near fertilizer plants, copper ore leach plants, and petroleum refineries. This is because elemental sulfur is cheaper to transport than sulfuric acid. By far the largest amount of sulfuric acid is used to make phosphoric acid, used, in turn, to make the phosphate fertilizers, calcium dihydrogenphosphate, and ammonium phosphates. It is also used to make ammonium sulfate, which is a particularly important fertilizer in sulfur-deficient. In various concentrations, the acid is used in the manufacture of fertilizers, pigments, dyes, drugs, explosives, detergents, and inorganic salts and acids, as well as in petroleum refining and metallurgical processes.

The expansion joint was fabricated from A516-70 carbon steel and painted with a special epoxy coat for protection from corrosion. The unit is 96″ x 124-1/4″ O.D. All of the butt welds for this expansion joint were 100% liquid penetrant, 100% radiographic, and soap and air bubble tested prior to shipment. This type of joint can be used as a “clamshell” joint used in conjunction with shell and tube heat exchangers, steam exhaust, hot water return lines, or chilled water lines.

Rectangular Fabric Expansion Joint for a Heat Recovery System at a Cement Plant

Ptp fabric expansion joint 147379

U.S. Bellows, Inc. designed and fabricated this rectangular fabric expansion joint for a heat recovery system at a cement plant in Indiana. The unit was fabricated with a high-temperature PTFE fabric belt and carbon steel frame. The dimensions are 197″ in length, 118″ in width, and 18″ face-to-face. The expansion joint is designed for an operating temperature of -20°-400°F at +/- 60″ water column and 1″ of axial compression and lateral offset. A dye-penetrant exam was performed on all welds before shipment.

Fabric expansion joints are often used in ducts that carry hot gases at low pressures. The major design parameters are the temperatures and flow rates of the gases and the amount and abrasiveness of solids suspended in the gases. Rectangular fabric expansion joints are also used in power plant ducting that requires joints from the boiler or economizer outlet to the chimney.

Also, they can be used on ducting to the coal pulverizers and the furnace-air inlets. Combustion turbines will also use these types of joints in exhaust and heat-recovery ducts. The primary duct movement this type of joint absorbs is axial expansion and contraction due to temperature changes. The expansion joint designer can also design for lateral and angular movements. Elastomers and Plastomers are the basic flexible materials used to construct the belting material for these joints. These sheets can be used in combination with woven glass, metal wire, fluoroelastomers, insulation, and other materials for use in applications where there may be abrasive material, condensate, acids, and other particles that could reduce the expected life of the joint. Our experienced engineers are also skilled in the various methods and fasteners to connect the belting material to the metal frames of the expansion joint.

This expansion joint was designed for a cement plant for one of the largest building material manufacturers worldwide. Such facilities make products ranging from fly ash, slag, masonry, white, specialty and oil well cements for use in commercial construction, residential construction, and industrial applications.



26′-10″ Long Universal Expansion Joint & Ductwork for a Chemical Plant


Us bellows universal expansion joint 144495

Type: Universal Expansion Joints with Ductwork
Size: 322″ Centerline-to-Centerline | 48″ Diameter
Material: 304 Stainless Steel | Carbon Steel
Design 400°F Operating Temp. @ 91 psig | 3.3″ Lateral
Testing: 100% Dye-Penetrant | PMI | Hydro-tested

U.S. Bellows custom designed this 26 ft. -10 in. long universal expansion joint with ductwork for a chemical plant. The bellows, ductwork, and flanges were fabricated from 304 stainless steel and the rest of the components from carbon steel. The unit is designed for 48″ diameter piping with an operating temperature of 400°F at 91 psig and 3.3″ of lateral deflection. The expansion joint was completed in 12 weeks and was 100% dye-penetrant, PMI, and hydro-tested before shipment. Chemical plants for which these are typically required process chemicals such as ethylene oxide/glycols, toluene diisocyanate, methylene diphenyl isocyanate, hydrochloric acid, polyether polyols, butanediol, GBL, n-methyl pyrrolidone, tetrahydrofuran, 2-pyrrolidone, PVP/PVPi, specialty amines, aniline, acetylene, surfactants, polytetrahydrofuran, and methylamines. The end products include furniture, automotive antifreeze, foams, carpets, construction, steel pickling, oil well acidizing, biodegradable plastics, lithium-ion battery production, pharmaceuticals, agriculture, gas treatment, water treatment, toothpaste, detergent, spandex fibers, engineered high-performance plastics, and animal feed.

U.S. Bellows has the scale and manufacturing agility to produce expansion joints and ductwork ranging in order size from a small scale of sub-1000 of dollars to upwards of 1M dollar large capital projects. We regularly support overnight lead times and tight project deliverables with evolving project requirements per the client and site needs. Last month, over half of our production capacity, was dedicated to this kind of work. A glimpse into our capabilities is outlined below from some projects we did last year:

– Refurbished 6, 48″-64″ diameter refractory-lined expansion joints for a large Houston refinery during a 45-day turnaround
– Completed a large ducting project for a major chemical facility in Texas with on-time delivery
– In the last 6 months, 40% of our expansion joint jobs have shipped in 2 weeks

We invite you to visit our facility and meet our team to get a first-hand look at our capabilities for your upcoming projects.


Neoprene Expansion Joints for a Combined Cycle Power Plant

Neoprene Expansion Joints for a Combined Cycle Power Plant in Western Europe

These neoprene expansion joints were custom-designed for a gas turbine facility in Western Europe. Neoprene expansion joints are typically used in turbine inlets and turbine exhaust and can accommodate the full temperature of hot gas flows while absorbing the thermal expansion and reducing stresses in the system. Neoprene expansion joints can be lined with different materials such as metal, fiberglass, or PTFE for increased temperatures. These types of expansion joints can also absorb contraction in cryogenic lines and assist in reducing vibration. In addition to gas turbines, these units can be used in coal-fired plants, renewable energy plants such as Biofuels Green energy plants, geothermal plants, chemical and other types of power plants where high-pressure pulsations and turbulent flow conditions exist.

Some other end applications for these types of expansion joints include:

  • Engineered wood building products (such as OSB)
  • Building materials such as cement, concrete, and aggregates
  • Carbon blacks for industrial, automotive, and conductive coatings, pigments, tire components, mechanical/industrial rubber goods (including membrane roofing, automotive rubber parts)
  • Metal ore mining

The expansion joint is a conical design and is 42” x 36” and 12” face-to-face. The fabric belt is made from reinforced neoprene and the framework is made from stainless steel and incorporates the use of stainless steel bolting to prevent corrosion. Units can be supplied with several different bolting patterns and configurations to accommodate various operation/installation requirements or allow access for periodic maintenance. They are designed for an operating temperature range from-30-120°F with a +/- 100” water column and 1” of axial compression and 1.25” lateral deflection. A 100% dye-penetrant test was performed before shipment. US Bellows, a subsidiary of Piping Technology and Products, has a long history of providing neoprene and fabric type expansion joints to meet the parameters, temperatures, and flow rates of gases and can be designed to operate when there are abrasive solids that could be suspended in the gases. Due to our experienced staff, we offer the special ability to both assist in the design and development of expansion joints along with the ability to manufacture these units at our 450,000 Square feet facility to meet your specifications. Our expansion joint capability has been greatly expanded production and allowed us to meet customer expectations on the most demanding projects from refurbishments to replacements, to new innovative designs for emerging verticals such as waste-to-energy plants aimed at reducing carbon footprint. In the last 6 months, we shipped over 40% of our expansion joints in two weeks or less to meet customer timelines and deliverables.

Expansion Joint with “Testable” Bellows for Auxiliary Column Overhead Line

Custom Universal Tied Expansion Joint with 2-Ply "Testable" Bellows for an Auxiliary Column Overhead Line

U.S. Bellows, a division of PT&P, custom-designed universal tied expansion joints with oversized, testable bellows for an auxiliary column overhead line in a refinery. This design can also be used in BioFuels plants, Wastewater Treatment Plants, and various Green Energy facilities. The expansion joint pictured is 100″ long and fabricated with carbon steel flanges, liner, cover, and hardware. The bellows are 36″ diameter and formed utilizing Inconel-625 LCF material. The expansion joints are designed for an operating temperature of 650°F at 50 psig with 2.75″ lateral movement. Tests included dye Penetrant examination of all welds, x-ray test of butt-welds, and bellows long seams. We conducted PMI tests on all alloys along with the welds, as well as, a pneumatic test and bellows ply leak test.

The bellows, being two-ply, provide for 100% redundancy; therefore, if a leak occurs in the inner ply (which can be detected by a leak detection system), the outer ply is designed for the full pressure and temperature. Pipe strain, misalignment, and vibration can affect the lifecycle of expansion joints located near pumps, compressors, and other rotating equipment. This design allows for the critical piping system to continue operating while plans for replacement can be formulated. This can prevent unexpected shut-downs saving field maintenance valuable time and money. Two-ply bellows also make it possible to pressure test (using the installed test ports) and inspect for leaks during field inspections and in some cases, if conditions permit, the expansion joint can be tested while in service. Most expansion joints in oil refineries, especially FCC units use two-ply bellows, but they are also ideal for regenerated catalyst standpipe, spent catalyst standpipe, recirculation cooled catalyst flue gas piping, and hot gas expanded piping.


It is the force generated by the expansion joint due to the pressure inside. As shown in the picture, we have seen several incorrect ways to calculate the thrust force of an expansion joint. Per the EJMA  Standards, as well as ASME Section VIII B&PV Codes, the Pressure thrust is calculated by multiplying the Bellows Effective Area, corresponding to the mean diameter of the convolutions of the Bellows by the Pressure of the line.

Universal Elbow Expansion Joints for Glycol Heat Transfer Piping

Universal Elbow Expansion Joints for Glycol Heat Transfer Piping
U.S. Bellows, a division of PT&P, custom-designed universal elbow expansion joints for glycol heat transfer piping for one of the largest chemical and refining companies in the world. Such industrial complexes produce chemicals such propylene oxide used for making plastic goods, tertiary butyl alcohol used in making flavors, perfumes, and as a solvent, ethylene oxide is used as an intermediate product in the production of fabrics and antifreeze, polypropylene is used for making consumer products such as those for automobiles, and Catalloy process resins which are used in packaging and automotive production. Glycol heat transfer enables effective process cooling. The bellows, flanges, plates, pipe, nuts, and threaded rods are all fabricated from 304 stainless steel and the units were painted for added protection. The expansion joints are designed for a 16” NPS and are 68-3/8” long. They are designed for an operating pressure of 67 psig at 378°F with 854 lb/in. axial spring rate and 0.2” of axial compression and with 205 in/lb lateral spring rate and 1.51 in lateral movements. Both expansion joints were hydro-tested at 101 psi and QC inspected before shipment. Generally, a universal expansion joint is composed of two bellows connected by a common pipe or center spool. This type of assembly allows any combination of the three basic movements: axial, lateral, and angular allowing for safe absorption of temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seismic activity. In addition to expansion joints, PT&P provides a full range of engineered pipe supports, pre-insulated supports, shock control, restraint, and support devices, ASME fabricated vessels, tanks, pig launchers, and more.

Externally Pressurized X-Flex Expansion Joints for a Overseas Facility

Externally Pressurized X-Flex Expansion Joints for a Overseas Facility

“Decarbonation” and “Carbon Neutral” are two key terms used to describe efforts to lower the amount of greenhouse gasses emitted into the atmosphere. Efforts are now underway to gradually convert existing Coal-Fired, HRSG (Heat Recovery Steam Generated or Natural Gas Powered) and other power plants utilizing fossil fuels onto plants that emit far fewer greenhouse gasses into the atmosphere. U.S. Bellows, Inc. received unique specifications to design and manufacture externally pressurized expansion joints for a facility overseas. The bellows are fabricated from 316 stainless steel and all other components are carbon steel. They are designed for a temperature of 200°F at 150 psig with 8″ axial compression. The units are 4″ NOP x 63″ L, 6″ NPS x 61.44″ L, and 12″ NPS x 64″ L.

3d drawing externally pressurized ej 171063Externally pressurized pipe expansion joints, also known as X-Flex expansion joints, are suited for piping systems that require large amounts of axial compression or extension. In externally pressurized pipe expansion joints, the bellows elements are arranged so that the media flow is on the external surface of the bellows. Externally pressurizing the bellows eliminates pressure instability as a limitation to the design and permits the absorption of large amounts of axial expansion. Our QC department conducted various NDT examinations (X-Rays, PMI, Penetrant Tests, and Hydro Tests). Also provided were “weld maps” and MTR’s for client review and inspection. At U.S. Bellows, we are constantly developing and assisting client engineers in this effort toward decarbonation by designing innovative products to accommodate new and unusual design specifications.

Custom Single Ply X-Flex Bellows Designed for a Manufacturing Company of Flooring Products

Custom Single Ply X-Flex Bellows Designed for a Manufacturing Company of Flooring Products

U.S. Bellows customized single-ply X-Flex bellows for the world’s largest manufacturer and supplier of flooring products with locations throughout the U.S. Flooring products such as carpet, ceramic tile, natural stone, laminate, vinyl, and hardwood require many of the same piping systems as traditional indoor plants for the automotive, food processing, semiconductor, textile, and pulp & paper industries. Plants that manufacture flooring are usually quite large requiring large tracks of land. As a result, the “pipe runs” can extend hundreds of feet requiring various types of expansion joints to accommodate the movement of the pipe while also relieving stresses in the piping system. Externally pressurized expansion joints are especially suited for piping systems that require large amounts of axial compression or extension. In externally pressurized pipe expansion joints, the bellows elements are arranged so that the media flow is on the external surface of the bellows. Externally pressurizing the bellows eliminates pressure instability as a limitation to the design and permits the absorption of large amounts of axial expansion. These expansion joints are fabricated with 304 stainless steel bellows, flanges, and pipe. They are designed for 300°F at 14.7 psig with an 8″ extension. The units are 3″ pipe x 40″ long, and 4″ pipe x 40″ long. The expansion joints were hydro-tested and underwent NDE quality control inspection tests such as liquid penetrate inspection (LPI) before shipment.