2020 Tech Report Jan-Feb

Task # 2.a.: Cleaning a Strainer in a Configuration “A” Control Group: Drain Valves

ACTION

COMMENT

13.

When pressure has bled off, close Valve “C.”

14. 15.

Remove hose from Valve “C.”

Check for any remaining pressure by carefully opening Valve “C.” If any pres- sure exists as evidenced by a strong am- monia odor, reattach the hose to Valve “C” and repeat the pumpout procedure (Steps 12 through 15) of this Mainte- nance Procedure. Verify that the strainer and / or strainer and control group has been isolated and pumped out. Ensure that all ammonia refrigerant in the isolated section with the strainer is pumped out to 0 PSIG. 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.

If pressure continues to exist, it may be neces- sary to repeat this task to ensure all valves are tightly closed. If the problem persists, inform your supervisor or facility contact.

NOTE: The strainer control group should re- main under Refrigeration Operator / Techni- cian control throughout this procedure. If not, the possibility exists that conditions may have been altered after isolation, requiring the rep- etition of this Task.

16.

17.

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

18.

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

19.

20.

21.

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

22.

Fully close Valve “C.”

23.

Reinstall the plug in Valve “C.”

RETA TECHNICAL REPORT PAGE 9