Abnormal shutdown analysis and technical transformation of ESD block valve - A case study of initial compressor station of Trans-Asia Gas Pipeline

Abnormal shutdown of ESD block valve occurred in the initial compressor station of Trans-Asia Gas Pipeline. At the time of on-site check, it was discovered that the muffler of SHAFER pneumatic-hydraulic actuator ceaselessly sprayed hydraulic oil outward. In addition, at the time of restoration to the ESD, it was found that the ESD block valve automatically opened abnormally. Thorough investigation revealed that the abnormal shutdown of ESD block valve resulted from the transfinite operating temperature of control module in the remote ESD cabinet due to high temperature, whereas the control logic defect of ESD and the poor contact of ESD switch of SHAFER actuator were the primary causes for the automatic open of ESD block valve at the time of ESD restoration and the oil spray of muffler of SHAFER actuator at the time of on-site check. Finally, by means of corresponding technical transformation and defect rectification, the potential risk of abnormal shutdown of ESD block valve in the initial station was completely eliminated, which guarantees the safe and smooth running of Trans-Asia Gas Pipeline.