Solenoid valve reliability in lower power operations

If a valve doesn’t operate, your process doesn’t run, and that is cash down the drain. Or worse, a spurious journey shuts the process down. Or worst of all, a valve malfunction results in a dangerous failure. Solenoid valves in oil and fuel purposes management the actuators that transfer massive process valves, including in emergency shutdown (ESD) systems. The solenoid needs to exhaust air to allow the ESD valve to return to fail-safe mode every time sensors detect a harmful course of scenario. These valves should be quick-acting, sturdy and, above all, dependable to prevent downtime and the associated losses that happen when a process isn’t running.
And that is much more necessary for oil and gasoline operations where there is limited energy available, similar to distant wellheads or satellite tv for pc offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to function accurately can’t solely cause expensive downtime, however a upkeep name to a distant location also takes longer and costs more than a neighborhood repair. Second, to cut back the demand for power, many valve producers resort to compromises that truly cut back reliability. This is bad sufficient for process valves, however for emergency shutoff valves and different safety instrumented systems (SIS), it’s unacceptable.
Poppet valves are typically better suited than spool valves for distant areas because they’re less complex. For low-power functions, search for a solenoid valve with an FFR of 10 and a design that isolates the media from the coil. (Courtesy of Norgren Inc.)
Choosing a reliable low-power solenoid
Many components can hinder the reliability and efficiency of a solenoid valve. Friction, media flow, sticking of the spool, magnetic forces, remanence of electrical present and material characteristics are all forces solenoid valve producers have to beat to construct probably the most dependable valve.
High spring drive is key to offsetting these forces and the friction they cause. However, in low-power functions, most manufacturers need to compromise spring drive to permit the valve to shift with minimal energy. The discount in spring force results in a force-to-friction ratio (FFR) as low as 6, though the commonly accepted safety degree is an FFR of 10.
Several components of valve design play into the amount of friction generated. Optimizing each of these allows a valve to have larger spring drive whereas nonetheless maintaining a excessive FFR.
For example, the valve operates by electromagnetism — a current stimulates the valve to open, allowing the media to move to the actuator and move the method valve. This media could additionally be air, but it may also be pure gasoline, instrument fuel or even liquid. This is very true in distant operations that must use no matter media is on the market. This means there’s a trade-off between magnetism and corrosion. Valves by which the media is out there in contact with the coil must be made from anticorrosive supplies, which have poor magnetic properties. A valve design that isolates the media from the coil — a dry armature — permits the usage of highly magnetized material. As a end result, there is no residual magnetism after the coil is de-energized, which in flip allows quicker response times. This design additionally protects reliability by stopping contaminants within the media from reaching the inner workings of the valve.
Another issue is the valve housing design. Usually a heavy (high-force) spring requires a high-power coil to beat the spring power. Integrating the valve and coil right into a single housing improves efficiency by stopping vitality loss, permitting for the use of a low-power coil, leading to much less energy consumption without diminishing FFR. This integrated coil and housing design also reduces heat, preventing spurious journeys or coil burnouts. A dense, thermally efficient (low-heat generating) coil in a housing that acts as a heat sink, designed with no air hole to entice warmth around the coil, virtually eliminates coil burnout issues and protects process availability and security.
Poppet valves are typically better suited than spool valves for remote operations. In record time lowered complexity of poppet valves increases reliability by lowering sticking or friction factors, and reduces the number of elements that can fail. Spool valves often have massive dynamic seals and heaps of require lubricating grease. Over time, especially if the valves are not cycled, the seals stick and the grease hardens, leading to higher friction that have to be overcome. There have been reviews of valve failure as a result of moisture within the instrument media, which thickens the grease.
A direct-acting valve is the solely option wherever attainable in low-power environments. Not only is the design less advanced than an indirect-acting piloted valve, but in addition pilot mechanisms often have vent ports that can admit moisture and contamination, leading to corrosion and allowing the valve to stay in the open place even when de-energized. Also, direct-acting solenoids are specifically designed to shift the valves with zero minimal pressure necessities.
Note that some larger actuators require excessive move rates and so a pilot operation is important. In this case, you will need to ascertain that every one elements are rated to the identical reliability rating as the solenoid.
Finally, since most remote areas are by definition harsh environments, a solenoid put in there will have to have sturdy construction and be in a position to face up to and operate at excessive temperatures while nonetheless sustaining the same reliability and safety capabilities required in less harsh environments.
When choosing a solenoid management valve for a distant operation, it’s potential to find a valve that does not compromise efficiency and reliability to reduce back power demands. Look for a high FFR, simple dry armature design, nice magnetic and heat conductivity properties and sturdy building.
Andrew Barko is the gross sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion model components for energy operations. He presents cross-functional experience in software engineering and enterprise improvement to the oil, gas, petrochemical and power industries and is certified as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the necessary thing account manager for the Energy Sector for IMI Precision Engineering. He presents expertise in new enterprise development and customer relationship management to the oil, gasoline, petrochemical and power industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).
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