Smith Flow Control - The common sense approach to valve safety
08 July 2014
Working in the oil and gas industry can be tiring and stressful, especially in extremely hot environments like the Persian Gulf. Workers operating valves are exposed to constant heat and noise and undertake dangerous, repetitive tasks that often require intensive labour.
Contractual staffing arrangements combined with hazardous working conditions can result in physical injury and an increased risk of accidents and loss of product. 70% of accidents in the Oil & Gas industry are attributed to the ‘human factor’.
Human Factors Engineering (HFE) is the design of work processes and systems to ensure the safe and efficient functioning of workers by taking into account human capabilities, limitations and requirements.
Valve systems must be designed for safety, rather than placing sole responsibility on the operator. Distractions, misunderstandings, shift change-overs or simple blunders can all lead the operator to make catastrophic errors. Simply relying on operator adherence is not enough – safety must be applied to the process itself. The focus then becomes accident prevention, not accident management.
Mechanical interlocks remove the ‘human factor’ by ensuring dangerous processes happen only in a designated sequence. They are simple mechanical locks designed as integral-fit attachments to the host equipment such as valves and closures – any equipment needing human intervention. Workers transfer specific keys from lock to lock (equipment to equipment) in a particular sequence. Each step in the process is only allowed once the previous step has been completed and the sequence must be followed in the exact order to completion.
Mechanical interlocks are ideally suited to integrate with permit-to-work procedures. Indeed, the Cullen Report on the Public Inquiry into the Piper Alpha Disaster (1990) strongly recommended the use of locking systems integrated with permit-to-work procedures, especially where routine procedures cannot be accomplished in the time-scale of a single work shift. They ensure safety, rather than place responsibility on the operator. Well-designed key interlock systems are always operator-friendly – they require no additional effort than normal procedures would require and, most importantly, should never permit more than one key to be free (available) at any one time.
Principles of HFE can be applied to the physical operation of valves onsite. Some valves can require over a hundred turns using excessive, sustained force by several operators at once. Portable valve operating systems such as the EasiDrive can reduce the stress on workers and improve productivity, especially with valves that require a high number of turns or are otherwise difficult to operate because of high torque or where excessive heat makes operations more challenging.
Valves may also be located in dangerous or inaccessible areas and require permanent access. But unavoidable constraints on accessibility mean that operators have difficulty ensuring valves in critical service are properly open or closed. Remote valve operating systems are the common sense approach to these valves, ensuring that operators are kept at a safe distance while valves are actuated efficiently. Remote valve operators, such as the FlexiDrive can pass through walls and floors and operate valves via a drive cable at distances up to 30m. It allows workers to stay in safe designated areas while critical valves are operated remotely.
Many routine procedures are potentially dangerous if executed incorrectly or in unsafe conditions. By taking simple steps to integrate safety into valve operating systems, workers are protected and operations proceed in a designated, safe way. Interlocks are versatile building blocks that can be configured to meet almost any simple or complex procedure. In addition, portable or remote valve drive systems are cost-effective ways to operate difficult to open and/or hard to reach valves, protecting personnel while increasing efficiency. It really is common sense!
About Smith Flow Control
Smith Flow Control is a British company specialising in mechanical valve control equipment. This includes procedural control using mechanical valve Interlocks and activity management systems, EasiDrive portable valve actuators, and FlexiDrive mechanical valve linkage systems for remote and/or simultaneous valve operation.
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