Which component should be removed when pressure testing a vessel?

When pressure testing a vessel, the relief valve should be removed to ensure accurate test results and maintain safety. The primary function of a relief valve is to vent excess pressure, which is essential for protecting the vessel from overpressure scenarios during normal operation. However, during testing, the relief valve could prematurely open due to the applied pressure, leading to inaccurate measurements of the vessel's integrity and pressure holding capability.

By removing the relief valve, you prevent this premature opening, ensuring that the pressure test reflects the true strength and sealing capability of the vessel without interference. This step is critical for verifying that the vessel can safely handle its intended operating pressures without any risk of leaks or failures. Other components, while essential for the functioning of the vessel, do not impact the pressure testing process in the same way, which is why they remain in place during the test.