Equipment Venting and Drainage

This section covers low point drains and high point vents, as well as connections 

Disposal of Drainage of Process Equipment Contents - When items of onsite process equipment are taken out of service, either individually during plant operation or for general turnaround, means of draining and safe disposal of the residual liquid hydrocarbon contents must be provided. The following are important considerations and terminology in the design  

The term vessels in refinery operations is generally meant to include towers, drums, and miscellaneous onsite equipment such as filters, strainers, separators, etc. Heat exchangers are normally considered separately. 

The term inventory refers to liquid hydrocarbon contents at the top of the working level range. Tray holdup is included, but piping contents are disregarded. 

Controlled release to the atmosphere should be at least 15 m from any continuous ignition source. 

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