ASME VIII Div.1 & TEMA Class C Tube Bundle for Geothermal Power Plants

ASME VIII Div.1 & TEMA Class C Tube Bundle for Geothermal Power Plants

We are a professional manufacturer of shell and tube heat exchangers and replacement tube bundles, serving the global energy, petrochemical, and industrial markets. We hold ASME U and U2 stamps, and our workshop is equipped to handle large-diameter shells and heavy bundles up to 120 tons. Every bundle is produced under strict quality control, with full traceability, hydrostatic testing, and third-party inspection available upon request.

Product Attributes

1. Tube Count & Geometry: 3,510 seamless or welded carbon steel tubes, 15.875 mm OD × 2.11 mm min. wall, 7,000 mm straight length, laid out in 30° triangular pattern with 19.844 mm pitch.

2. Design Codes: ASME Section VIII Div. 1 with TEMA Class C, plus applicable client specifications for geothermal service.

3. Pressure & Temperature Ratings: Tube side design 42 bar(g) at 110°C, shell side design 11 bar(g) at 130°C; operating temperatures 50°C tube side / 65°C shell side.

4. Materials: Carbon steel shell, channel, tubesheet, baffles, and tube bundle; gaskets KAMPROFILE 316L + flexible graphite.

5. Corrosion Allowance: 1.6 mm on both shell and tube sides, with full radiographic examination (100% RT) on shell and channel butt welds.

6. Weight & Dimensions: Empty shell weight 67,500 kg, bundle weight 57,000 kg, full of water 114,000 kg; designed for horizontal mounting with saddle supports.

Application

This high-pressure recuperator tube bundle is specifically designed for use in binary cycle geothermal power plants, where it recovers heat from butane vapor (shell side) to preheat butane liquid (tube side).

Tube Bundle Configuration

The bundle contains 3,510 carbon steel tubes, each measuring 15.875 mm in outside diameter with a minimum wall thickness of 2.11 mm. The tubes are 7,000 mm long and arranged in a 30-degree triangular pattern at a pitch of 19.844 mm. This dense layout maximizes the number of tubes within the given shell diameter while still allowing adequate clearance for cleaning and maintenance. The tube side is configured with two passes, directing the butane liquid through half the tubes in one direction and returning through the remaining half, thereby increasing fluid velocity and enhancing heat transfer coefficient.

Design Conditions and Performance

The bundle is designed for a tube side pressure of 42 bar(g) at 110°C and a shell side pressure of 11 bar(g) at 130°C. Operating conditions are milder: tube side butane liquid at 50°C and shell side butane vapor at 65°C. A corrosion allowance of 1.6 mm is applied to both sides to extend service life. The design code is ASME Section VIII Div. 1 together with TEMA Class C, and the vessel carries the ASME U stamp. Joint efficiency is taken as 1.0 for all full-penetration welds.

Fabrication and Quality Control

Every tube-to-tubesheet joint is strength-welded and then subjected to a leak test followed by a hydrostatic test on the completed bundle. The shell side and tube side are tested separately. Non-destructive examinations include 100% radiographic testing on all shell and channel butt welds, ultrasonic testing on plates as required, and magnetic particle or penetrant testing on nozzle welds. Post-weld heat treatment is not required per code for the selected materials and thicknesses.

Conclusion

This HP Recuperator tube bundle represents a robust, high-performance solution for geothermal ORC applications. Built to stringent international codes and backed by full documentation, it delivers reliable long-term service in demanding cyclic duty. For inquiries about similar bundles for your project, please contact our sales engineering team.