Pressure Sciences' expertise includes all aspects of high energy piping (HEP) systems. We have performed piping and hanger condition assessments at many power plants, and at chemical and food process plants in conjunction with OSHA 1910.119 requirements. We have expert knowledge and abilities in both the ANSI/ASME B31.1 & B31.3 piping codes, and API design and in-service inspection codes, including the recently enacted API-570 Standard.

Some examples of recent work include:

Fossil Power Plant Assessment and Remediation

Pressure Sciences' Sr. Piping Specialist, John Breen, has worked with the City of Austin, TX, for several years in HEP projects at the Decker Creek Power Station Units 1 and 2, including providing outage support for repair of systems requiring remediation. System distress in Unit 1 occurred as a result of differential settlement of the turbine-generator foundation and the plant buildings, resulting in many hanger failures. In addition, the seam welded Hot Reheat system was found to be defective, and John provided design and construction surveillance support for its replacement.

In Unit 2, hanger failures occurred, and John performed in-plant computer stress analyses that included actual piping wall thickness and insulation thickness to establish the basis for stress and dead and live weight analyses. This revealed significant underdesign of the hangers, which caused interferences and potentially excessive nozzle loads on sensitive equipment, such as the boiler header and turbine. We provided piping design remediation, hanger modification specifications, construction surveillance, outage support and hanger settings for this project.

Chemical Plant Piping System Exposed to High Seismic Loads

Union Carbide engaged Pressure Sciences to evaluate and qualify the large diameter reaction gas recycle piping system for their licensee's plant in the Far East. The need for this evaluation was prompted by the very high seismicity in the region. Pressure Sciences' work included evaluation of soil conditions and development of soil-springs for soil-structure interaction analysis, and for use as boundary condition input to the TRIFLEX® computer model.

Based on the ground acceleration of 0.29 g's, horizontal and vertical response spectra were developed for the dynamic (response spectrum) seismic analysis. Parametric studies were performed to assess the sensitivity of the results to calculated soil-spring stiffness, in order to verify that the high calculated stresses were, in fact, a result of the piping system design, and not induced by the computer model itself. Finally, recommendations were provided for modifications (including a redesign of the pipe supports) that would alleviate excessive pipe stresses and loads on rotating equipment.

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