tubesheet

A tubesheet is a thick, flat plate with a precisely arranged pattern of holes that receive and secure the ends of tubes in vessels such as shell-and-tube heat exchangers, condensers, reboilers, and boilers. The tubesheet provides structural support for the tubes and establishes a seal between the tube side and the shell side. Tubes are joined to the tubesheet by methods such as mechanical expansion, welding, or soldering to form leak-tight tube-to-tubesheet joints.

In shell-and-tube equipment, tubesheets are commonly designed as single or double configurations. A single tubesheet anchors the tubes to one side, with the opposite end either free or terminated. A double tubesheet arrangement uses two plates with a shell-side space between them to provide an additional barrier against leakage and to accommodate thermal expansion. Some designs employ a floating tubesheet to permit differential expansion between the shell and tube bundle, while others use a fixed tubesheet.

Materials for tubesheets depend on service conditions and typically include carbon steel, stainless steel, or nickel-based alloys. Hole patterns may be square or triangular, and the number, size, and spacing of holes are chosen to meet heat-transfer and pressure requirements. Tolerances, plate thickness, and joint integrity are critical for reliable operation. The tube-to-tubesheet joint is usually formed by tube expansion or welding; the tubesheet may also be integral to the shell in some designs, with the shell-tubesheet interface sealed by gaskets or mechanical clamping.

Standards and practice for tubesheets are described in boiler and pressure-vessel codes and heat-exchanger guidelines, such as the ASME Boiler and Pressure Vessel Code and TEMA recommendations, which address design, fabrication, and inspection considerations. Regular inspection guards against corrosion, cracking, and leakage.