What should you do last after adjusting the high pressure on the 51-AF-4 valves pressure relief controls before leaving the area?

The final step after adjusting the high pressure on the 51-AF-4 valves' pressure relief controls is to cap and seal them. This action is crucial because it ensures that the adjustments made cannot be tampered with or inadvertently altered after you leave the area. Properly capping and sealing the controls also helps maintain their integrity and functionality, preventing any unintended pressure changes that could occur due to environmental factors or accidental contact.

While securing other components such as jam nuts or adjusting screws is important—these actions contribute to the stability of the adjustments—capping and sealing them ultimately protects the entire system from potential issues. Turning off solenoid switches is typically a separate procedure that deals with system operation rather than the adjustments made to the pressure relief controls.

In summary, capping and sealing the adjustments is the final protective measure that ensures the system remains safe and functions as intended after the adjustments have been made.