PSV and Flare Analysis

Vega Oil and Gas Consulting team executed pressure relief device and flare header analysis for numbers of gas processing and fractionation plants in Louisiana, Oklahoma, Ohio, and Texas. In addition, Vega Oil and Gas Consulting evaluated relief devices on various vessels and storage tanks for a specialty chemical / pharmaceutical company in Utah.

Performed relief device and system sizing requirements for a new cryogenic gas processing plant

Vega Oil and Gas Consulting worked with the EPC company to perform the engineering analyses and assist in developing specifications for relief devices and the system. Specifically, this involved the following:

• Identifying overpressure scenario analysis
• Quantifying required relief rate for each applicable overpressure scenarios
• Developing global overpressure scenario analysis
• Proposing inlet and outlet piping limitations to meet API 520/521 criteria.
• Preparing PRV datasheets for procurement.
• Analyzing flare header design (sub-headers and header size / length)
• Performing knockout drum (KOD) sizing analysis
• Performing flare radiation analysis to determine placement of flare at the site.

Evaluation of relief device and system sizing for a gas fractionation plant

As part of a plant debottlenecking effort, Vega Oil and Gas Consulting evaluated the existing relief device, Knock Out Drum (KOD) and flare sizes
relative to the higher plant throughput rate. Specifically, this effort involved:

• Reviewing existing relief valve analyses and flare header analysis
• Re-evaluating rate dependent overpressure scenarios at higher throughput rate including inlet and outlet pressure drop analyses
• Determining “pinch” reboiler duties associated with various column to estimate realistic relief rates
• Re-evaluating KOD and flare radiation
• Proposing mitigation options to resolve deficiencies to meet higher throughput rate

Evaluation of flare header modification

As part of a client’s project to reroute the existing underground flare piping to a newly constructed, aboveground header system and add relief valves to existing flare system, Vega Oil and Gas Consulting evaluated the relief
devices and new header system. Specifically, this effort involved:

• Performing backpressure analyses for all PSVs discharging to flare based on re-configured piping
• Proposing changes to several PSV types based on total backpressure analyses
• Re-evaluating the existing global relief scenarios and added relief valves as required
• Identifying and proposing necessary changes to prevent liquid pockets in flare headers
• Proposing new Knock Out Drum sizing

Performed relief device and vent header analysis for specialty chemical / pharmaceutical plant

Vega Oil and Gas Consulting performed pressure relief devices, specifically, rupture disks and vent header system analysis. Specifically, this involved the following:

• Identifying overpressure scenario analysis
• Quantifying required relief rate for each applicable overpressure scenarios
• Performing total back pressure analysis to meet API 520/521 criteria
• Developing global overpressure scenario analysis
• Analyzing vent header design (sub-headers and header size / length)
• Providing mitigation options to meet API 520/521 standard and/or RAGAGEP