In spite of the various mandatory equipment (helmet, gloves, goggles, safety shoes...) that a valve operator must wear, incidents are still frequent in industries or municipalities.
Why are these interventions risky? What are the causes of these incidents and how can they be reduced?
Every valve operator is trained to have a thorough knowledge of the valve environment (handling, control, inspection). This training is especially crucial when workers operate in hazardous areas.
Approximately 50% of the valves are manually operated, in most cases the required torque is greater than the operator's capacity.
In order to open a valve it is often necessary to exert a high torque to initiate valve movement, often blocked by various deposits or too infrequent use of the valve, this torque can sometimes be so high that the operator cannot open/close the valve by himself. In this case the risks are multiple:
When an operator operates a valve without tools, the valve may be opened and closed by judgment. When the operator senses that the force on the handwheel is high enough, the operation is considered complete. However, over time, valves wear out and no longer require the same torque. The closing or opening of the valve will therefore be incomplete, which can lead to risks and losses for the company.
In various cases, whether in industry (petrochemicals, mining ...) or in municipal water management centres, it is common to find valves that are difficult to access. The operator is in an uncomfortable position and sometimes has to turn a handwheel through a balustrade above the vacuum. In this case he puts his safety at risk and cannot carry out his task efficiently and accurately.
The refinery operator is confronted on a daily basis with tasks in an environment where large quantities of gas or oil are processed. These products are flammable and explosive but also toxic and polluting, a simple leak in a pipe can become a major incident.
Some valves can guide the flow of odourless, invisible and non-irritating gas, if the valve is mishandled the operator may be in an environment where highly toxic gas is released.
Some valves are coupled to a gearbox, the opening and closing operation requires a very large number of turns of the handwheel. The work is very long, repetitive and physical. This effort necessarily leads to muscular fatigue of the operator(s) in charge of these valves.
In case of poorly maintained equipment, or when a valve is not exercised often enough, the risk of premature failure increases.
We know that the operators' environment is risky, which is why it is necessary to prioritise safety in the choice of tools and new technologies to be used.
Solutions exist to turn a steering wheel remotely via a system of pulleys and long cables. These sometimes very expensive systems seem to be the ideal solution to reduce the costs of operations that are sometimes under water, or in inaccessible environments. But this solution cannot be considered complete, as it does not guarantee the safety of the operator.
In fact, the system produces significant resistance due to the length of the rope and the friction in the pulleys. This resistance is an additional difficulty for the operator who will have to force more on the steering wheel, which leads in the short term to muscular pain and then musculoskeletal disorders.
It's common to see self-taught people getting into the business of building tools to help them with their daily tasks. They create hand tools using pneumatic drills that generate a very high torque to turn their valves faster. However, these tools are not designed to be reliable, and the operator has to contain the force generated by the tool at arm's length, resulting in a very violent shock when the valve reaches the end of its stroke (musculoskeletal disorders).
This tool is used to generate a larger lever arm on a steering wheel. Usually used on valves that are difficult to operate, the user tends to force too much on them. This leads to over-stressing the handwheel, which can twist, but also damage the valve. The operator has to exert a lot of force, which can also lead to musculoskeletal disorders.
Inserting a long metal bar through the steering wheel to turn it is also not a good solution. This requires a lot of effort for the operator(s) turning the valve. There is a large amount of elbow pain for valve operators who use this technique. In addition to the safety of the operator, this technique is very damaging to the handwheels as well as to the valves.
There are many ideas, sometimes simple and effective, but always make a compromise between operator safety, valve life and operating time. In high-risk industries, it is not possible to use unreliable, and/or poorly dimensioned technologies.
The modec range of actuators has been designed for valve operators. Safety is our priority! They are ingenious tools allowing safety for the operator but also for the installation; and this without any compromise in performance. The modec actuators are extremely efficient and considerably reduce operating times.
Read also: "3 reasons to use a portable rotary actuator on water distribution networks" to find out how to protect distribution network operators with portable valve actuators.