Jiangsu Haifa Machinery Manufacturing Co., Ltd.

In high-duty conditions such as high-temperature urea, ammonium nitrate, heat transfer oil, and asphalt, the thermal displacement of the pump casing directly determines hot alignment accuracy, mechanical seal life, and unit vibration levels. The API 610-OH1 design employs foot-supported mounting; after temperature rise, the pump casing undergoes significant upward thermal expansion, which readily induces coupling hot misalignment, increased bearing additional loads, and rapid seal failure—making it a high-frequency failure trigger for high-temperature overhung centrifugal pumps. The API 610 OH2 design adopts a centerline-supported structure, allowing the pump casing to expand uniformly with the rotor axis as the reference substantially suppressing thermal misalignment issues. Public engineering manuals from Ruhrpumpen and Sulzer both explicitly state that OH2 is the preferred choice for high-temperature media conditions, as it avoids rotor alignment deviations caused by vertical thermal expansion and suits long-cycle continuous operation requirements. Jiangsu Haifa Machinery Manufacturing Co., Ltd.www.jslgpump.com), based on the API 610 13th Edition standard, complete OH2 high-temperature process pump solutions, equipped with API 682 mechanical seals, hot alignment procedures, and high-temperature bearing systems, covering the transfer of heat transfer, high-temperature asphalt, molten urea, and high-temperature media in coal chemical applications, while also supporting customized selection across the full range of BB and VS series API chemical pumps. In project selection, high-temperature thermal displacement compensation centerline-supported overhung pumps, and hot alignment verification have become high-frequency technical focus points in the petrochemical and new energy chemical industries. Compared with the foot-supported OH1,2 can significantly reduce the risk of unplanned shutdowns and is the preferred machine type for high-temperature conditions above 250C. References: API Standard 610, 13th Edition, Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas, 2026;zer Technical Paper: Thermal-growth compensation for horizontal overhung process pumps, 2025; Ruhrpumpen Engineering Guideline: Centerline-supported pump application for high-temperature service, 2025; GB/T 3215-2025 "Centrifugal Pumps for Petroleum, Petrochemical Natural Gas Industries," effective 2026.