A total of three rectangular fabric expansion joints and six round fabric expansion joints were custom designed for an offshore oil extraction and natural gas project. The rectangular joints are 56″ x 81″ I.D. x 25″ O.A.L. and the round joints are 105″ dia. x 24″ O.A.L. 309 stainless steel was used for the duct, 310 for the liners, 316 for the covers, 321 for the studs, 309 for the flanges. The fabric belt was a three layer belt with an inner layer of glass cloth, a layer of KO wool and an outside layer of reinforced PTFE. The expansion joints were designed for 1 psig at a temperature of 1100°F. The rectangular joints were designed for 2″ axial compression, a 1″ extension, and a 1″ lateral offset. The round joints were designed for 4″ axial compression, a 1″ extension, and a 0.5″ lateral offset. All welds were dye penetrant examined.
B31.1 Operations and Maintenance
According to ASME B31.1 Chapter VII Par. 140 a program shall be established for the assessment and documentation of the condition of all CPS (Covered Piping Systems) in power plants.
CPS Systems are defined in Chapter 1 Par 100.2, as systems on which condition assessments are to be conducted. This includes the following systems as a minimum.
NPS 4 and larger main steam, hot reheat steam, cold reheat steam, and boiler feedwater piping.
NPS 4 and larger systems that operate above 750°E (400°C or above 1,025 psi (7,100 kPa)
Other systems may be included as CPS by an Operating Company, based on their judgment. Appendix V of the code is titled ‘Recommended Practice for Operation, Maintenance, and Modification of Power Piping Systems’. This addendum is non-mandatory; however many Power Industry operating companies’ insurance carriers are now invoking Appendix V with increasing frequency, and this is affecting conditions of their agreements with the operating companies.
Piping Technology and Products Inc. (PT&P) has for some time been performing surveys and assessments in accordance with part H of Par. 140, that requires hot and cold walk-down readings and assessment of pipe supports, operated within the creep regime of the pipe. These assessments are helpful in identifying, sagging lines, deformation of supports, and damage caused by upset conditions, and/or incidents, attributable to operational malfunctions, dynamic/thermal or hydraulic events.
PT&P has been performing this service for many power generation companies. Preparation of documentation, retrieval and compilation of files for a CPS assessment, has just been completed for a major U.S power generation company. Ten large power plants were involved, and the original predominantly high-energy pipe support drawings, all engineered and designed by PT&P, were retrieved from PT&P archives dating back ten years.
Please feel free to contact us at firstname.lastname@example.org and we will be happy to answer any of your technical questions about our survey capabilities, as well as any other engineering or field services that your organization may need.
U.S. Bellows 101: Expansion Joint Basics Webinar
This Webinar is over… to view the recording, go to http://www.usbellows.com/news/webinar_index.html
* Live Webinars are approved for 1 PDH credit for TX P.E.’s
This presentation will briefly touch on the basics of fabric expansion joints; however, is mainly focused on the various designs, material details, and applications. Learn how fabric expansion joints are engineered and fabricated for various applications and the many factors that influence those designs. View the abundance of materials used, including Fluoroplastic and Fluoroelastomer, and their respective capabilities. Take a journey through a Fossil Fired Power Plant and see exactly where fabric expansion joints are required.
U.S. Bellows, Inc., a division of PT&P, has more than 50 years of experience designing and manufacturing expansion joints, along with replacement and repair services.
The two assemblies shown, a mitered elbow duct work and fabric expansion joint and duct work assembly, are designed for a sulfuric acid plant. Both assemblies are fabricated from 1/4" thick 304L stainless steel. They are designed for a 15" water column with a temperature of 180°F, axial compression of 3/4", and lateral movement of 3/4". A dye penetrant examination is performed on all welds prior to shipment.
Are there fabric expansion joints in your future? Are you looking to design or purchase a fabric expansion joint or just curious about the assortment of available frames? View different types of metal attachment styles for fabric expansion joint designs.
Metal Attachment Frames with Baffles and Insulation Pillows
These expansion joints have PTFE-lined rubber convolutions with Inconel® 625 liners and stainless steel covers. They measure 10″ I.D. x 5-1/4″ OAL. The expansion joints are designed for 46 psig and temperatures up to 210°F, with 1/2″ axial compression.
We recently added new diagrams to the U.S. Bellows website. Check out all of the different components that make up a custom fabric expansion joint versus a standard expansion joint.
Diagram of High Temperature, 3-Layer Expansion Joint
Diagram of Standard Fabric Expansion Joint
This rectangular fabric expansion joint is designed for high air circulation flow for an air cooling loop duct in a power plant. It measures 81″ L x 18″ W x 16″ face-to-face, and is fabricated with stainless steel angle, frame ends and internal liner. The fabric belt material is reinforced silicone fabric cloth, which can withstand temperatures up to 550°F. This expansion joint is rated for axial movement of +/- 1″ with a 1/2″ lateral offset. A dye penetrant test on all welds was conducted prior to a quality assurance inspection prior to shipment.
The externally pressurized expansion joints are 37.5″ in diameter and 36″ face-to-face. The bellows are 304 stainless steel, and the flange and ring are carbon steel. This expansion joint is rated for 232 psig with 5″ axial compression and temperatures up to 189°F. All bellows longitudinal welds were 100% x-rayed, all carbon steel welds were dye penetrant examined and each unit was hydro-tested to 348 psig. A total of 56 units were fabricated for a cooling system in a new university for women in the middle east.
This 48-3/4″ diameter single metallic expansion joint will be used in a heat exchanger. The bellows are 321 stainless steel and the pipe is 304 L stainless steel. This expansion joint is rated for 145 psi with 1″ compression and temperatures up to 600°F. The unit was 100% x-ray tested, hydro-tested and 100% dye penetrant tested.