2020 Tech Report Jan-Feb

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Task # 3.c.: Returning an Alternate Control Group Configuration to Service

ACTION

COMMENT

NOTE: Work quickly and do not stop the procedure as there is a possibility of a hydro- static lock, which can result in ruptured piping and a release of ammonia!

Remove locks and tags and slowly open the Upstream hand valve isolating the section of the Ammonia Refrigeration System. Check for ammonia odor. If a small ammonia leak is observed, the source of the leak should be inves- tigated and the leak repaired. If a large leak occurs, perform emer- gency isolation, secure the area to prevent unauthorized personnel from entering; Close, lock and tag upstream hand valve, notify safety personnel and pumpout the isolated section. See Task # 2.c. If automatic valves are located within the section of the Ammonia Refrigeration System being worked on, change the au- tomatic valve(s)’s manual operating stem to the “AUTOMATIC” operating position for any automatic valve in the isolated piping.

NOTE: Do not stop the procedure at this point. this can create a hydrostatic lock and can result in ruptured piping and a release of ammonia! NOTE: If any of the automatic valves is a mo- torized valve, a special tool may be required to change the position of the valve when it is de-energized. Please see the manufac- turer’s Operation and Maintenance manuals for specific requirements. See the Operation and Maintenance Manuals in the PSM / RMP Program.

10.

11.

Remove locks and tags and slowly open the downstream hand valve isolating the section of the Ammonia Refrigeration System. Remove PPE, clean, perform any re- quired preventive maintenance and stow. Secure all tools and equipment utilized. Complete the work order and return it to the Senior Mechanic.