Our White Papers

Compliance with the Process Safety Management (PSM) Standard is challenging for even the most sophisticated operators because of the broad scope and highly technical nature of the 14 PSM elements. This paper provides guidance on how to comply with the three elements

This paper reviews the potential causes leading to the incident, as well as summarizing the lessons that can be learned from the video clip. Additionally, it emphasizes the need for a complete and thorough Process Safety Management program.

The process industries are primarily concerned with the reliability, availability, auditability, and maintainability of relief and flare systems data. These data are critical component of process safety information and its lifecycle must be properly managed to ensure sound process safety management and loss prevention programs.

A detailed risk-based approach is proposed for addressing flammable and toxic dispersions impacting occupied buildings. The approach is based on the results from a complete quantitative risk-based assessment (QRA), which provides the following information per each outcome impacting the target location under analysis

QRA as a technique for managing and understanding risks dates back to the 1970s, initially applied in the aerospace, electronics, and nuclear power industries.

Effective design of emergency relief systems requires accurate modeling. In particular, the PVT relation of such systems is fundamental and unique. This relation must be accurately represented during direct scale-up or computerized simulation. Variables which can significantly alter the PVT behavior of a system should be quantified, and included in the design.

Challenges associated with PRV stability issues for existing installations are not unique to any particular segment of the chemical process industry. This is an industry wide problem that has received a lot of attention from both OSHA and industry associations such as API, ACC, and AFPM. A consistent definition of what constitutes an Engineering Analysis is currently being proposed by API/ACC/AFPM for inclusion in the upcoming revision to API 520.

In this paper we provide a simplified model for the assessment of PRV stability where the inlet line geometry is simple and/or where the inlet line acoustic length can be established. This simplified model has also been proposed in the 3rd ballot of API-520 part II.

How to avoid the singing PRV problem. Excitation of acoustic standing waves in a main process flow line closed side branch, such as the inlet line of a pressure relief valve (PRV), can occur due to vortex shedding generated by increased flow in the main process line. The flow velocity for process lines where pressure relief devices are mounted via a side branch should be limited to where ce is the effective isentropic speed of sound of the main process flow pipe fluid system, u is the maximum allowable fluid flow velocity in the main process line, and d/L is the pressure relief device inlet line diameter to length ratio. This limit can be very restrictive for flashing two phase flow.

An independent and accurate estimation of the speed of sound can provide an important quality check for a multitude of single and multi-phase flow applications. More recently, proposed screening methods for the calculation of pressure relief valve (PRV) stability require an accurate estimate of the speed of sound for the fluid/piping system. This paper outlines

Get a handle on PRV stability. There is general agreement that the 3% inlet pressure loss rule (IPL3) is not sufficient to guarantee PRV stability and does not work all the time. This is confirmed by recent findings from actual PRV stability measurements and dynamic modeling. IPL3 only considers irrecoverable pressure loss. IPL3 assumes that the fluid dynamic pressure is ultimately recovered at the disk surface as the PRV is closing.

Even before the adoption of ISA-S84.013 as a national standard, safety instrumented systems (SIS) were used to mitigate the risks of process hazards. With the establishment of the standard, there is now a framework for defining Safety Integrity Levels (SIL) for such systems and the associated reliability requirements.

Asset Integrity (also referred to as Mechanical Integrity) findings remain on top of OSHA’s citation list during PSM inspections. Violations most frequently found include failure to address equipment deficiencies, lack of AI written procedures, and failure to perform internal AI inspection(s) and test performance.

Ever since OSHA implemented their National Emphasis Program in 2007, facility’s pressure relief systems design basis have come under increasing scrutiny. Recognizing that they may not be fully compliant, many companies are conducting audits of their relief systems design basis to determine their current state, identify gaps, and establish a path forward for compliance.

Properly conducted interviews of witnesses following an incident are as important to understanding what occurred, as is saving data and information following an incident (presented in the first paper of this series).