Solenoid valve reliability in lower energy operations

If a valve doesn’t operate, your process doesn’t run, and that is cash down the drain. Or worse, a spurious trip shuts the process down. Or worst of all, a valve malfunction leads to a dangerous failure. Solenoid valves in oil and gas purposes control the actuators that transfer large course of valves, including in emergency shutdown (ESD) methods. The solenoid must exhaust air to allow the ESD valve to return to fail-safe mode every time sensors detect a harmful process situation. These valves should be quick-acting, durable and, above all, dependable to stop downtime and the associated losses that happen when a process isn’t running.
And this is even more essential for oil and fuel operations where there could be restricted energy available, such as remote wellheads or satellite tv for pc offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to operate correctly can’t solely cause costly downtime, but a maintenance call to a distant location also takes longer and prices more than a neighborhood repair. Second, to reduce the demand for power, many valve manufacturers resort to compromises that really scale back reliability. This is dangerous sufficient for process valves, however for emergency shutoff valves and other safety instrumented systems (SIS), it’s unacceptable.
Poppet valves are generally better suited than spool valves for distant locations as a result of they’re much less complex. For low-power functions, look 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 performance of a solenoid valve. Friction, media move, sticking of the spool, magnetic forces, remanence of electrical current and materials characteristics are all forces solenoid valve producers have to beat to construct probably the most dependable valve.
High spring pressure is key to offsetting these forces and the friction they trigger. However, in low-power purposes, most producers should compromise spring pressure to permit the valve to shift with minimal energy. The reduction in spring force results in a force-to-friction ratio (FFR) as little as 6, though the commonly accepted safety stage is an FFR of 10.
Several components of valve design play into the quantity of friction generated. Optimizing every of these permits a valve to have larger spring pressure while nonetheless maintaining a excessive FFR.
For example, the valve operates by electromagnetism — a current stimulates the valve to open, permitting the media to move to the actuator and move the method valve. This media could also be air, however it might also be pure gas, instrument gas or even liquid. This is particularly true in distant operations that must use whatever media is out there. 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 — allows the utilization of highly magnetized material. As a end result, there is not a residual magnetism after the coil is de-energized, which in turn allows faster response occasions. This design also protects reliability by stopping contaminants within the media from reaching the inside workings of the valve.
Another factor is the valve housing design. Usually a heavy (high-force) spring requires a high-power coil to overcome the spring energy. Integrating the valve and coil into a single housing improves efficiency by preventing energy loss, allowing for using a low-power coil, resulting in much less energy consumption without diminishing FFR. This built-in coil and housing design additionally reduces heat, stopping spurious trips or coil burnouts. เกจวัดแรงดัน1บาร์ , thermally environment friendly (low-heat generating) coil in a housing that acts as a heat sink, designed with no air hole to entice heat across the coil, nearly eliminates coil burnout considerations and protects process availability and security.
Poppet valves are generally better suited than spool valves for distant operations. The decreased complexity of poppet valves will increase reliability by decreasing sticking or friction points, and reduces the variety of parts that can fail. Spool valves usually have large dynamic seals and a lot of require lubricating grease. Over time, particularly if the valves aren’t cycled, the seals stick and the grease hardens, leading to greater friction that have to be overcome. There have been reviews of valve failure due to moisture within the instrument media, which thickens the grease.
A direct-acting valve is the greatest choice wherever attainable in low-power environments. Not only is the design less complicated than an indirect-acting piloted valve, but additionally pilot mechanisms usually have vent ports that may admit moisture and contamination, leading to corrosion and allowing the valve to stay within the open place even when de-energized. Also, direct-acting solenoids are specifically designed to shift the valves with zero minimum pressure requirements.
Note that some bigger actuators require high move rates and so a pilot operation is necessary. In this case, it could be very important confirm that every one components are rated to the identical reliability rating as the solenoid.
Finally, since most remote locations are by definition harsh environments, a solenoid installed there must have strong development and be capable of face up to and function at extreme temperatures whereas still sustaining the same reliability and security capabilities required in much less harsh environments.
When deciding on a solenoid control valve for a distant operation, it is possible to find a valve that does not compromise performance and reliability to scale back energy calls for. Look for a excessive FFR, simple dry armature design, nice magnetic and heat conductivity properties and robust building.
Andrew Barko is the sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion brand elements for energy operations. He presents cross-functional experience in utility engineering and enterprise growth to the oil, gas, petrochemical and energy industries and is licensed as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the vital thing account supervisor for the Energy Sector for IMI Precision Engineering. He provides experience in new business development and buyer relationship management to the oil, fuel, petrochemical and power industries and is certified as a pneumatic specialist by the International Fluid Power Society (IFPS).
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