Abstract:

 The structure characteristics and working principle of transfer line valve in the cracking furnace of the 220 kt/a ethylene plant at PetroChina Dushanzi Petrochemical Company are analyzed. The effect of anti-scorching steam on transfer line valve and the causes of the blockage of anti-scorching steam line are analyzed. By taking a series of measures including installing flanges downstream the steam line valve and upstream the injection point hand valve, installing heat tracing for steam lines and strengthening daily maintenance, the hidden danger of anti-scorching steam line blockage of transfer line valve was successfully eliminated.

Key words: pyrolysis gas valve')">pyrolysis gas valve,  ')">anti-scorching , ')">steam, daily maintenance