The Importance of a PSSR

PSSR inspectors looking at air conditioning system

Lacking the understanding of how to work with pressure systems can pose serious safety hazards.

From steam boilers and autoclaves to compressed air systems and hydraulic presses, pressure vessels and equipment are ubiquitous across many industries.

Failure or misuse of these systems can lead to catastrophic explosions, damage, injuries, and even loss of life.

two PSSR inspectors in high vis safety uniforms discussing

Pressure Systems Safety Regulations for Beginners

In this blog post, we aim to provide a helpful guide to Pressure Systems Safety Regulations (PSSR) for non-specialists. We clearly cover fundamentals like definitions of pressure systems, explanations of risk areas, overviews of current regulatory standards in various jurisdictions, and more. Additionally, we detail practical steps that operators, installers, and maintainers of pressure systems must take to ensure full compliance with all applicable PSSR codes and provisions.

Whether you own a facility with boilers and steam pipes or are a technician responsible for servicing and testing compressors and cylinders, understanding the safe installation, operation, maintenance, and repair requirements for the pressure systems you work with is essential. Use this PSSR guide to improve your working knowledge of critical safety protocols and better prevent avoidable pressure system failures at your workplace. With vigilance and proper precautionary measures, the inherent risks of working with gases and liquids under pressure can be effectively reduced.

Risk Assessment

Risk assessments are an integral component of PSSR. Risk assessments ensure employee and equipment safety during facility start-up and identify any potential hazards that must be addressed. It is vitally important that these risks are assessed efficiently, as any delays could result in costly accidents or equipment damage.

An effective PSSR process must involve a multidisciplinary team. This should include employees from engineering, operations, quality, and safety departments; their expertise will help identify any potential safety concerns that need addressing and mitigation. A multidisciplinary team can also identify inefficiencies or potential areas for process improvements that would benefit from more thorough addressing.

An effective PSSR checklist must include a thorough walk-through of process equipment to verify compliance with design specifications. Furthermore, all safety, operating, maintenance, and emergency procedures must be in place and checked against an ongoing Process Hazard Analysis (PHA), with action items resolved prior to start-up as well as staff training on safe process operation.

The walk-through should involve inspection of tanks, vessels, reactors, mixers, piping, and instrumentation, as well as reviewing any applicable operator and safety manuals for each piece of equipment. Prior to proceeding with the walk-through, it is important to review and approve any action items raised from PHA/MoC systems.

BP’s Texas City refinery and two other sites had previously experienced incidents that resulted in severe injuries, financial loss, and disruptions to production. These incidents were due to improperly conducted safety critical checks; one such valve caused steam release, which caused an explosion and fire, while in another incident, an alarm failed to activate due to portable trailers being too close.

An effective PSSR checklist can reduce risks and help avoid accidents, saving both time and money. A regular review ensures the checklist remains relevant by reflecting changes to processes, equipment, and regulations, plus it ensures its ability to identify and mitigate employees’ health and safety threats effectively.


An effective PSSR checklist can be an invaluable way to verify that equipment and systems are ready to go online. The process identifies any issues that must be corrected prior to starting, as well as providing all of the required documents. Ideally, a review should be conducted by a team with various backgrounds and experiences so as to cover every angle.

Start by collecting all relevant information, such as operating instructions, P&IDs and maintenance records. It is also beneficial to familiarise yourself with your equipment and system so as to recognise any potential hazards and risks.

Prioritise items according to their level of risk. Prioritising items according to their level of risk will help ensure that the most essential safety issues, especially those containing hazardous chemicals or energies, are not overlooked and that thorough and accurate inspections are conducted.

At the time of an inspection, it’s a good idea to conduct a PSSR walk of the equipment in operation and identify any potential issues not evident during the static inspection. You should also test equipment controls and emergency shutdown procedures to ensure their correct function before compiling a written report outlining their results.

Once the inspection is complete, you can close the Process Safety Master File and begin bringing online any equipment identified through inspection or review. Any corrective actions identified should be implemented prior to starting up and documented accordingly in the Process Safety Master File. You should also note any lessons learned and provide recommendations for improvements for future reviews.

An efficient PSSR process depends on having the proper tools to streamline its execution, increasing both productivity and overall efficiency. A caFM (computer-aided facility management) solution can help schedule inspections, document results, track action items, and reduce downtime while increasing safety in the workplace.


As with any process, it’s essential that specific procedures and protocols be in place during PSSR. This includes creating tailored checklists specific to the equipment or facility being surveyed, conducting walk-throughs, testing controls to detect hazards and risks, and prioritising items based on risk; this ensures the most critical safety aspects are attended to first.

Training employees on how to correctly utilise checklists and identify issues is an important step. This will ensure they use them fully and optimally, improving safety and compliance in turn.

As per the project scope, it may also be beneficial to include third-party participants in the review for technical expertise and input into the PSSR process. It’s essential that any action items and recommendations generated during PSSR be monitored to ensure all issues have been effectively addressed prior to the beginning of the operation of facilities or equipment.

Undergoing a PSSR before opening or modifying an existing facility helps ensure its as-built condition is in line with design specifications, all associated processes are safe for operation and all necessary permits have been secured. When making modifications to an existing process, it is important to conduct a PSSR to keep its process safety information updated and relevant.

Implementing a comprehensive PSSR checklist from the beginning of operations sends a strong signal to employees that safety is of utmost importance, helping create a culture of safety throughout an organisation and leading to lower workplace accidents, equipment damage, regulatory fines, and ultimately increased productivity. A safe working environment also results in lower absenteeism rates and improved morale, which has direct ramifications on company bottom lines. With proper PSSR implementation, companies can reap all these advantages while remaining compliant with industry regulations, ultimately making any investment well worth it!


Companies dealing with hazardous fluids and chemicals need Process Safety Systems Review (PSSR), or Facility and Equipment Review, as part of their Process Safety Management (PSM) programme to ensure safe operations before starting up new or modified processes. This means examining designs, construction, and installation to identify any potential hazards or risks that could cause accidents, employee injuries, or prevent unexpected downtime due to equipment failure. This process helps avoid accidents as well as downtime due to equipment failure.

PSSRs can protect workers and the environment by preventing hazardous materials from entering the atmosphere or water bodies and by protecting both facilities and equipment from fires, explosions, or any other environmental hazard. A PSSR requires a multidisciplinary team comprised of members from engineering, maintenance, operations, and safety to perform an in-depth review of processes and associated equipment. As this may take several weeks to complete, it is vital that it be planned ahead to allow enough time for this review process to take place.

Clearly define the roles and responsibilities of your PSSR team and give the leader enough authority to defer starting a process if significant deficiencies are identified. Failure to do this could cause substantial financial loss, so it’s imperative that they possess both skills, knowledge, and the willpower to resist pressure to allow a deficient process to commence operation.

The PSSR process not only ensures all the required documents are present but also performs checks for safety systems to make sure they are functional and functioning effectively, inspects equipment to make sure it’s ready for use, and checks to see that construction and equipment conform with safety, environmental, and health regulations and standards.

PSSRs are an integral component of PSM programmes and are required by both OSHA and the EPA. Successful PSSRs can prevent incidents, equipment damage, employee injuries, and downtime. ProcessMAP’s PSSR app provides configurable checklists with built-in functionality for identifying deficiencies or suggesting recommendations, as well as tracking action items until their completion.

Application of the Pressure Systems Safety Regulations Explained

PSSR applies to pipework, equipment, and protective devices that form pressure systems operating under pressure and contain relevant fluids, whether that be steam, gas, or liquid under pressure; transportable pressure receptacles, etc.

Regulation 9 of the PSSR stipulates a written scheme of examination that the user or owner must ensure complies with. The scope and scale of such schemes depend on the size and complexity of the systems being examined.

Identifying a Pressure System

Pressure systems refer to any vessel or other equipment that encloses fluid at more than 0.5 bar pressure and stores this pressure in either an enclosed container or surrounding pipework; should anything go amiss, it could result in serious injuries or even fatalities.

Pressure systems in the workplace are typically designed for specific tasks, such as filling a car or cooking food. Safety devices may include pressure relief valves or other means of relieving pressure, such as bursting discs. They are typically made of metal, such as steel, with interlocked, overlapping elements.

At sea level, atmospheric pressure remains constant; this is known as atmospheric pressure. However, high and low pressure systems arise regularly around the globe as a result of water/air interactions in oceans, lakes, and rivers; these high and low pressure systems appear on weather maps as areas with relatively steep pressure gradients that may produce storms or tropical depressions.

The PSSR applies to most types of pressure systems; however, there are exceptions. These include systems that are pressurised unintentionally or solely during leak testing; pipelines under 2 bar atmospheric pressure; steam generators; beer kegs or containers similar in size up to a maximum capacity of 0.252 m3 at 12 bar atmospheric pressure; heat exchangers and refrigeration plants; as well as vacuum compression refrigerators that don’t exceed 30 bar working pressure with temperatures not exceeding 300 °C for steel vessels or 1000 °C for aluminium vessels, respectively.

If your system falls within any of these categories, be sure that an up-to-date written scheme of examination has been drawn up by a competent person and covers protective devices, pressure vessels, and sections of pipework that could fail and lead to dangerous situations if left without an examination plan.

Identifying the relevant fluid

If your pressure system contains fluids such as steam, gases under pressure, or liquids that become gases upon release into the atmosphere (for instance, liquids kept artificially under pressure and then released), you must have it evaluated in accordance with PSSR. A statutory examination conducted according to your written scheme ensures it remains suitable for its intended use while also detecting defects that could cause malfunction or create unsafe pressure conditions.

Safety limits of any pressure system must be clearly established and clearly marked on its vessels, for instance, including maximum safe operating pressures and temperatures, nature and volume of contents, operating timeframe, heat input or coolant flow rate, as well as any protective devices being properly functioning. In addition, its designer or supplier may need to provide more information in writing, including details regarding the operation of the pressure system, such as maximum and minimum pressures and temperatures, as well as the operating time, length, or emergency actions required during an incident.

Your system must also meet mechanical integrity criteria. Failure of any protective device shouldn’t lead to the sudden release of energy that poses risks for people or equipment. Installation processes should not impede maintaining and inspecting capabilities for the system; furthermore, no component should violate the PSSR-approved Code of Practice for Safety of Pressure Systems.

Make sure your duty holders and examiners are qualified to carry out their roles and responsibilities effectively, using criteria such as knowledge, skills, and independence from the operational functions of the organisation. Examiners in particular must be capable of recognising any potential safety issues related to pressure systems during examinations of these systems.

Identifying the equipment

Pressure systems can be broadly defined as any vessel, pipeline, or protective device containing fluid of interest that also houses it for safekeeping. They may also take the form of equipment (or a system of equipment such as a compressor or pump). A relevant fluid could include steam or any substance having a pressure greater than 0.5 bar above atmospheric (for instance, acetylene gas dissolving into liquid form is considered a relevant fluid) or hazardous or toxic substances that produce pressure within them (for instance, mercury).

Identification of pressure equipment within your system is critical when deciding how often and by whom it should be examined, as this determines when and who must examine it. Each piece falls into one of nine categories determined by fluid state and risk level; higher category numbers increase the risk of personal injuries or property damages from the failure of said equipment. A hazard chart can help you decide which category your pressure equipment falls into and the frequency of examinations.

Once you have identified the appropriate category of equipment for use, the next step will be drafting a Written Scheme of Examination (WSE). This legal document must be produced prior to starting up pressure systems; its creation or certification, as suitable, should be overseen by a “competent person,”, detailing both inspection frequency and nature.

WSE will cover all items within a pressure system that, should they fail, could pose potential danger. This includes vessels, pipework, and protective devices, but excludes transportable pressure receptacles (e.g., cylinders).

Make sure you’re fulfilling all of your PSSR obligations legally and properly by taking advantage of BCAS’ training courses. Our popular “Certificate in Understanding the Pressure Systems Safety Regulations” course gives in-depth knowledge of this key piece of legislation, helping meet compliance requirements for compressed air applications. Get in touch today; our friendly team is happy to assist!

Identifying the competent person

Identifying the competent person operating a pressure system is essential. Failing to do so could result in serious accidents and injuries; such events could involve large quantities of stored energy being released suddenly in an explosion-type incident or simply propel parts of equipment over long distances, potentially damaging people and buildings in their path.

Competent persons encompass people who possess relevant skills, knowledge, and experience; this could include engineers, technicians, or anyone working on the equipment on an everyday basis; employers or self-employed people responsible for operating or maintaining systems, as well as those providing repairs or maintenance services, are included within this definition.

A Written Scheme of Examination (WSE) is necessary for most systems, and an appropriately competent person must draw it up and certify its suitability. WSEs must also exist for all pressure systems within the scope of PSSRs (see paragraph 98).

It is vital that the scope of a written scheme adequately encompasses every part of a system that could pose any threat, such as protective devices and pressure vessels as well as parts of pipework that, should they fail, could release potentially dangerous levels of stored energy into the environment. Furthermore, an examination plan must identify both nature and frequency, as well as any special measures necessary for preparation prior to an exam being performed on an examinee system.

WSEs are required for all systems and should remain up-to-date at all times, even if the system is out of service. When systems undergo modifications or faults are revealed during inspection, the WSE should also be amended.

After each examination, the competent person must report back on the actual state and settings of a pressure system, as well as its safety components and settings, along with the safe operating limits of its components and settings. They will advise the owner or user if their perception of risk indicates unsafe operating limits for the system or suggest changes to operating limits or the frequency of examinations where needed.