2020 Tech Report Jan-Feb

Task # 2.c.: Cleaning a Strainer in an Alternate Control Group Configuration: No Drain Valves

ACTION

COMMENT

See the appropriate drawings. CAUTION: Opening the purge / drain valve too fast or too far can cause water / ammonia mixture to splatter from bucket. Refer to the equipment’s SOP and/or refrig- eration system P&ID’s. Refer to the equipment’s SOP and/or refrig- eration system P&ID’s. Refer to the equipment’s SOP and/or refrig- eration system P&ID’s.

13.

Slowly throttle open the purge / drain valve.

14.

When pressure has bled off, close the purge / drain valve. Remove hose from the purge / drain valve. Before opening the system/piping with the control valve, check for any remaining pressure by carefully opening the purge / drain valve. If any pressure exists as evidenced by strong ammonia odor, reat- tach the hose to the purge / drain valve, and repeat pump out procedure (Steps 13 16) of this Maintenance Procedure. If pressure continues to exist, it may be necessary to repeat the isolation pro- cedure to ensure all valves are tightly closed, followed by the pump out proce- dure. If the problem persists, consult your supervisor or facility contact. Slowly remove the bottom cap of the strainer or filter, either unscrewing the hex bottom or loosening the cover bolts. Slowly remove the screen / filter assem- bly and clean with a good solvent; blow dry and inspect. Lightly oil and place the gasket on the bottom cap. Carefully align the screen assembly in the center body and replace the bottom cover. Tighten cover / bolts in the accept- able prescribed manner.

15.

16.

CAUTION: Be careful to avoid any refrigerant which may still be in the strainer or filter. See the strainer Manufacturer’s Operation and Maintenance Manual for instructions.

17.

NOTE: If the screen is damaged or debris / sludge / sediments cannot be removed and cleaned, replace the screen assembly.

18.

19.

20.

Per ANSI/IIAR-2, valve gasket materials shall match valve manufacturer’s specifications, and shall be of the thickness specified.

RETA TECHNICAL REPORT PAGE 16