Valve Criticality Analysis (VCA) Service In Oman

Human Factors Engineering (HFE)

Human Factors Engineering is vital in the oil and gas industry for enhancing safety, efficiency, and overall system performance. By focusing on the human element in system design and operation, HFE helps
mitigate risks, optimize operations, and ensure the well-being of personnel.

Human Factors Engineering (HFE) ensures that designs consider human abilities, limitations, and expectations. This is crucial when designing products, workplaces, or systems like industrial plants, as it directly impacts safety, efficiency, and operational performance. HFE aims to create environments where people can work safely and effectively, reducing costs and enhancing overall system performance

The Problem of Poor Valve Placement:

If HFE principles aren't applied when designing a plant or equipment, crucial items like manual valves might end up in positions that are hard or dangerous to access. This can lead to several problems:

1. Operational Issues: If a valve is hard to reach, it might not be operable in emergencies, like during a fire or leak.
2. Maintenance Challenges: Inaccessible valves might not be maintained properly, leading to equipment failure or accidents.
3. Increased Costs: If special access methods (like scaffolding) are needed to reach a valve, maintenance becomes more expensive and time-consuming.
4. Safety Risks: Workers might injure themselves trying to reach these valves, which could involve stretching, crawling, or using ladders in unsafe ways.

Valve Criticality Analysis (VCA):

Given the complexity and space limitations of modern plants, it's impossible to place every valve in an ideal position. Therefore, VCA is used to make the best possible compromises. VCA is a method that evaluates the importance of each valve and helps decide where it should be placed.

What is Valve Criticality Analysis (VCA):

Valve criticality analysis is a systematic approach used to assess and prioritize valves in a system based on their potential impact on safety, operations, environment, and maintenance. The goal is to identify critical valves that require more rigorous inspection, maintenance, or even redesign to prevent failures that could lead to significant consequences

Purpose of Valve Criticality Analysis

Valve Criticality Analysis provides structure to the decisions that determine the location and accessibility of valves. The main goal of Valve Criticality Analysis VCA

• Ensure that safety-critical or frequently used valves are easy to access.
• Make sure that people can interact with valves comfortably and safely.
• Reduce the physical effort needed to operate valves by the people.

VCA not only improves safety and operability but also ensures that maintenance tasks are easier and quicker to perform, reducing the likelihood of human errors.

VCA is typically applied in the Front-End Engineering and Design (FEED) and Detailed Design phases of a major project, or as soon as initial layouts are available.

Key inputs to Valve Criticality Analysis are a good understanding of the tasks that people are required to perform, (in normal operations and in emergency situations), as well as an understanding of the capabilities and limitations of the people who will perform these tasks.

Benefits of Valve Criticality Analysis:

• Operational Reliability: Ensures that key processes remain operational, minimizing downtime.
• Environmental Protection: Helps prevent incidents that could lead to environmental harm.
• Structured Decision-Making: VCA formalizes the decision-making process, making it easier and quicker to decide valve placement without lengthy debates.
• Cost Efficiency: By applying VCA early in the design process, costly rework can be avoided, and unnecessary components like extra piping or platforms can be eliminated.
• Improved Human Performance: By designing with human interaction in mind, plants become safer and easier to operate and maintain. We can reduce the risk of accidents and injuries.

How VCA Works: Valves are categorized into three groups based on their criticality:

1. Category 1 (C-1): These are the most critical valves. They are essential for safety or operations and are used frequently. For instance, emergency shutdown valves or control valves fall into this category. These valves must be easily accessible, ideally from ground level or a permanent platform, to ensure quick and safe operation.
2. Category 2 (C-2): These valves are less critical but still need to be accessed occasionally. Examples include service oil valves or manual valves for normal startup/shutdown. While they should ideally be at ground level, it's acceptable to use fixed ladders or temporary platforms if needed.
3. Category 3 (C-3): These are the least critical valves, rarely used except during commissioning or special maintenance tasks. Their placement is less stringent, and permanent access is not always necessary.

The lower the criticality rating, the more freedom that a designer has in determining the layout and access requirements. Based on the Company’s standard HFE, the access and positioning requirements for each Category of valve should be clearly specified, along with the clearances around each Category of valve, labelling requirements, maximum forces required to operate etc. For example, Category 1 valves should be placed at waist/chest height, rather than below the knees or above the shoulders

The lower the criticality rating, the more freedom that a designer has in determining the layout and access requirements. Based on the Company’s standard HFE, the access and positioning requirements for each Category of valve should be clearly specified, along with the clearances around each Category of valve, labelling requirements, maximum forces required to operate etc. For example, Category 1 valves should be placed at waist/chest height, rather than below the knees or above the shoulders.

VCA Process:

Typically, VCA is conducted in workshops with input from various experts, including operations, maintenance, and safety personnel. Here's how it usually goes:

1. Preparation: Before the workshop, agree on which valves typically belong to each criticality category. This helps streamline the decision-making process during the workshop.
2. Review: Participants review the plant area using drawings or 3D models to understand the layout. Review drawings that contain proposed piping and instrumentation (PFDs and P&IDs).
3. Assessment: Each valve is then assigned a criticality rating (C-1, C-2, or C-3) based on its importance and frequency of use.
4. Documentation: A summary table is created, listing each valve's criticality, frequency of use, and any special notes. Drawings are also annotated with criticality ratings.
5. Implementation: The workshop's findings guide the final design and layout of the plant. If certain design aspects can't meet the VCA requirements, they are discussed with the client or company for resolution.
6. Ongoing Compliance: As the project progresses, the design is checked against the VCA outcomes to ensure compliance.

Training and Scale: In large projects, it might not be feasible for a human factors expert to review every valve. In such cases, design teams are trained on VCA principles to identify and raise potential issues with human factors professionals.

By understanding and applying VCA, engineers and designers can make informed decisions that enhance the safety, efficiency, and maintainability of complex industrial systems.