These custom designed pipe shoes were fabricated for main steam piping in a gold mine project. A total of forty-three pipe shoes ranging in size from 20″ to 36″ diameter were designed for temperatures up to 650°F. The shoes ranged in length from 17″ to 24″, width from 20″ to 32″ and height from 3″ to 7″. They are manufactured from carbon steel and have a two-coat paint system to protect against corrosion.

251 variable furnace springs were designed and fabricated for fertilizer production at a chemical plant in Virginia. The furnace cans are carbon steel and painted with red-oxide primer to avoid any potential hazards where exposed to high temperatures. This project included figures: PTP-1-120, PTP-2-150, PTP-2-180, PTP-4-100 and PTP-4-200 variable furnace springs with operating loads ranging from 1,042 lb. to 15,512 lb. A load test on all variable springs was conducted prior to shipment.

A total of eight big ton spring supports, “mega tons” were designed and manufactured to support two reactors in a power plant weighing approximately three million pounds each. The mega ton pictured incorporated eighteen individual spring coils to produce a load capacity of approximately 602,000 lb. and a spring rate of 112,500 lb./in. It was designed with eight Bronzphite® slide plates that measured 12″ x 12″. The 12″ x 12″ slide plate selection was based upon the ability to position individual squares across the load flange surface while simultaneously providing the total slide plate surface area required to support the operating loads.

By using individual slide plate squares, the fabrication and assembly time was reduced because a standardized mounting procedure could be incorporated and repeated as necessary for each big-ton load flange subassembly. Overall, the slide plates were incorporated into the design to reduce the horizontal forces which would be imparted onto the big-ton spring’s load flange during lateral deflection (movement) of the reactor.

Bronzphite® slide plates, in particular, were selected because these big-tons will be used in a location which will see continuous “cold-to-hot” operating cycles and as a result, the robust nature of Bronzphite® proved more advantageous than other types of slide plates. The other two designs used nine slide plates, one with fifteen individual coils to produce a operating load of 594,000 lb. and a spring rate of 250,050 lb./in. The other design had an operating load of 300,000 lb. and a spring rate of 106,000 lb./in.

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 david.baker@pipingtech.com 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.