Microsoft Word - SOP - Hands-On Sessions

Rev. 2 - Final

LINE BREAKING

PART A:

STEP NUMBER

SAFETY AND HEALTH HAZARDS/ STEPS TO AVOID DEVIATION

DESCRIPTION

1

Ensure that PPE is worn at all times and a full-face respirator equipped with NH 3 cartridges is always within reach when working with ammonia. Verify water source is nearby and operational. Determine isolation valve locations and develop a pumpdown procedure which may need to be approved by the service project manager, depending on project size or equipment that is being pumped out. Inform all affected personnel of intentions to perform a pump out and verify your supervisor is aware of your intentions. Follow pumpout procedure carefully in order to isolate the desired piping, valves or equipment from the system. Then re-walk the isolated section to verify that all valves have been closed and there are no other valves requiring attention. (see steps 5-9 for basic order of pumpout) First, stop liquid flow and then remove all liquid ammonia from piping or equipment according to pumpdown procedure. Drop pressure as much as possible and then close suction (or downstream) isolation valves. Connect an ammonia rated transfer hose to service valve on isolated piping or equipment and blow down remaining pressure into a bucket of water or through a Jetpump. Remove hose from water source as soon as pressure has dropped to 0 psig to prevent water from being pulled into the system by a vacuum or ammonia vapors. Monitor open service valve for 15 minutes to verify that all valves are holding and there is no pressure coming from the valve. If there is no pressure rise, work may begin on the cleared portion of the system.

Line breaks must only be performed by authorized and trained refrigeration technicians.

2

3

Informing others that may be affected will reduce the chance of false leak reports and lets others know where you are while working by yourself. Before actual line breaking occurs, cordon off work area from any traffic if necessary.

4

5

Water may be applied to help boil out remaining liquid.

6

May lower compressor setpoints or purge pressure into other parts of the system.

7

Depending on volume of vapor to be blown down.

8

Condensing vapors can cause a vacuum to form.

9

If pressure is still present, repeat valve isolation tasks to assure tightness of the valves and repeat the pump out. Leave service valve open to atmosphere to prevent pressure from building up and tagout.

Procedure: Line Breaking Reviewed: 10/26/2023

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