Challenge
A pipeline company in Northern California needed to blow down their natural gas pipeline for repairs and inspection. The 18” line was initially depressured to the minimum possible pressure, which still left 90 PSI of natural gas. Also, the zero-liquid condition could not be determined prior to operation.

Solution
Envent efficiently mobilized a high pressure separator and a thermal oxidizer to blow down the pipeline within a short period of time. After destructing the remaining gas in the line with the EMTOS unit, four volume line sweeps were performed to leave the piping free of residual gas. After the blow-down, the customer could reroute the interconnecting piping, hydrotest the new portion and recharge the lines back up to 400 PSI.

Benefits
Due to Envent’s sound planning and efficient engineering approach, the pipeline company could finish their modification on schedule and safely in environmental compliance of the local air board. A great saving was achieved when the downtime was reduced by Envent operations.

Four volume line sweeps were performed to leave the piping free of residual gas.