Dear All,

Please be informed the following regarding startup of ASP after shutdown started from 24th.

Before shutdown it was informed that ASP main air compressor bypass valve was not

functioning properly.During shut down we checked the valve and positioner was

replaced by E&A dept and trial taken. Foud Ok.ASP was started on 27th night after resuming the Electric Power and following activities

done incourse of time.During that time found chiller outlet valve not functioning properly. Same valve

overhauled and serviced and then taken in circuit.Thawing operation started on 28th morning and completed on 30th. During thawing it

was observed that main air compressor bypass valve not closing 100% as per

requirement. During 2 hrs short shutdown of Power Supply the bypass valve removed

from pipe line and found that valve seat got damaged physically. Same replaced by

spare valve available with us(with same actuator) after taking trial outside.ASP operation started after resuming power on 30th night at 20:00hrs.On 2nd July at 3:30pm ASP taken under shutdown because bypass valve was not closing

100% and there was huge loss in system pressure.Bypass valve removed and found similar damage in valve seat as earlier. Now we

replaced with original valve seat after modifying the valve mounting

arrangement matching with the existing actuator.After taking trial same fixed back.ASP started at 20:45hrs on 2nd July.Found everything normal.