Since putting 3660 MW units into operation at Shajiao C Power Plant

troubles of high and medium pressure steam valves have frequently occurred.It is believed from analysis that the main causes resulting in said troubles are due to long-term exceedng set standard for the quality of fire-resistant oil

The main causes leading oil quality to be not up to standard are as follows: local overtemperature

local standstill of oil flow

and insufficient regeneration etc..Through many measures for decreasing the temperature of servomotor

and strictly according to stipulation for carrying out periodic limber-up test of the steam valve

as well as retrofitting the regeneration facility etc.

the quality of fire-resistant oil has been effectively controlled

making the acid value to be less than 0.03 mg/g in a long period

and the resistivity to be greater than 1010 Ω·cm

diminishing occurence of steam valve's trouble.