Flare Header & Knock Out Drum Redesign


knock out drum

A refinery-wide flare study revealed a substantial deficiency in the capacity of a knock out drum in one of our client’s units. Without sufficient capacity or retention time, there was a threat of liquids being sent to the flare tip or vapors being routed to the facility's slop line in the event of system over-pressurization. The existing knock out drum was located underground, which also reduced the ability to inspect and maintain the system. Any modification needed to be completed within an existing turnaround schedule.


Valdes got to work evaluating layout options and performed front-end and detailed design services to properly size the refinery flare header and knock out drum. Our design included placing the tank above ground and elevating the pressure safety valves (PSVs) to prevent any back pressure, while rerouting the header across a 70’ long pipe bridge spanning a refinery access road. Valdes also selected and specified multi-stage vertical can pumps, with seal pots and several flow, pressure, level and temperature instruments and a closed loop flare sample station, as well as provided layout and stress analysis of large bore flare header piping.


Valdes delivered a design to install the flare header and knock out drum in three phases to coincide and be completed within the facility’s turnaround schedule. Hydraulic analysis was conducted on the existing slop line to ensure compatibility with the new system. The design incorporated various elements to ensure safe and reliable system operation.






Instrumentation & Controls

Pipe Stress Analysis

Piping & Plant Layout

Laser Scanning & Surveying

Project Management

Procurement Services