Key Inspection Points Before Commissioning a Shell-and-Tube Heat Exchanger

Initial Setup & Auxiliary Systems

The inspection begins with the fundamentals. Verify that the installation is fully compliant, has passed all necessary acceptance procedures, and that operators are properly certified. The work area must be clean and organized, with all auxiliary systems—such as water, electricity, ventilation, and fire protection—confirmed to be operational.

Physical Equipment Examination

A detailed physical examination of the equipment itself is next. Inspect the exchanger shell, flanges, nozzles, and supports for any visible defects like corrosion, deformation, cracks, or signs of leakage. Ensure all foundation and flange bolts are securely tightened and that gaskets are intact. Crucially, the exchanger must have successfully passed required pre-commissioning pressure tests (hydrostatic and/or pneumatic) to verify its structural strength and leak-tightness.

Safety Devices & Instrumentation

All safety devices and instrumentation must be checked for reliability. This includes confirming that safety valves are calibrated and within their valid certification period, and that pressure gauges, temperature indicators, and level glasses are properly installed, functional, and clearly legible. The associated piping and valve arrangement requires careful verification. Every valve—including inlet, outlet, vent, drain, and bypass—must be checked to ensure it operates smoothly and is set in the correct position (open or closed) for startup. Strainers or filters in the lines should be cleaned to prevent debris from entering and blocking the tubes.

Auxiliary Equipment & System Filling

For auxiliary equipment like circulation pumps, perform a rotation check by hand to confirm free movement without binding. Verify adequate lubrication and proper electrical grounding. Before introducing process fluids, the system should be slowly filled, typically with treated water, while diligently venting all air from the high-point vents of the exchanger and piping.

Startup Sequence & Thermal Management

Finally, the startup sequence itself must follow strict thermal and pressure management principles. Always begin by flowing the cooler medium first, followed by the warmer medium. Pressure and temperature should be increased gradually and smoothly according to established procedures. Avoiding sudden thermal shock is paramount to preventing damage from excessive stress. For units restarting after a prolonged shutdown, additional checks for internal cleanliness, corrosion, and insulation condition are necessary, and an even more conservative, slow heat-up profile is often required. The entire inspection process serves as a vital preventive measure, ensuring a controlled and safe transition from a static state to full operation.