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 results in a dangerous failure. Solenoid valves in oil and gasoline purposes control the actuators that move massive process valves, together with in emergency shutdown (ESD) systems. The solenoid must exhaust air to allow the ESD valve to return to fail-safe mode whenever sensors detect a dangerous process scenario. These valves have to be quick-acting, durable and, above all, dependable to prevent downtime and the associated losses that occur when a process isn’t working.
And that is even more necessary for oil and fuel operations the place there’s restricted power out there, corresponding to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to operate appropriately can not solely trigger costly downtime, however a upkeep name to a distant location additionally takes longer and prices greater than an area restore. Second, to scale back the demand for power, many valve producers resort to compromises that really reduce reliability. This is unhealthy sufficient for process valves, however for emergency shutoff valves and different security instrumented techniques (SIS), it’s unacceptable.
Poppet valves are typically higher suited than spool valves for distant locations as a result of they’re less advanced. 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 dependable 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 materials characteristics are all forces solenoid valve manufacturers have to beat to construct essentially the most reliable valve.
High spring pressure is key to offsetting these forces and the friction they cause. However, in เกจวัดอาร์กอน -power applications, most producers need to compromise spring pressure to permit the valve to shift with minimal power. The reduction in spring pressure ends in a force-to-friction ratio (FFR) as low as 6, although the widely accepted safety stage is an FFR of 10.
Several elements of valve design play into the quantity of friction generated. Optimizing each of these permits a valve to have larger spring force whereas nonetheless sustaining a excessive FFR.
For instance, the valve operates by electromagnetism — a present stimulates the valve to open, permitting the media to circulate to the actuator and transfer the process valve. This media may be air, but it may also be pure fuel, instrument fuel or even liquid. This is particularly true in remote operations that should use whatever media is out there. This means there is a trade-off between magnetism and corrosion. Valves in which the media is available in contact with the coil must be made from anticorrosive materials, which have poor magnetic properties. A valve design that isolates the media from the coil — a dry armature — permits the utilization of extremely magnetized material. As a end result, there isn’t a residual magnetism after the coil is de-energized, which in flip allows faster response times. This design additionally protects reliability by preventing contaminants within the media from reaching the inner workings of the valve.
Another factor is the valve housing design. Usually a heavy (high-force) spring requires a high-power coil to beat the spring strength. Integrating the valve and coil into a single housing improves effectivity by stopping energy loss, allowing for the usage of a low-power coil, leading to less power consumption with out diminishing FFR. This built-in coil and housing design also reduces warmth, preventing spurious trips or coil burnouts. A dense, thermally efficient (low-heat generating) coil in a housing that acts as a heat sink, designed with no air gap to trap heat around the coil, just about eliminates coil burnout concerns and protects process availability and safety.
Poppet valves are usually better suited than spool valves for distant operations. The decreased complexity of poppet valves increases reliability by lowering sticking or friction points, and reduces the number of parts that may fail. Spool valves often have massive dynamic seals and many require lubricating grease. Over time, especially if the valves usually are not cycled, the seals stick and the grease hardens, resulting in larger friction that have to be overcome. There have been reports of valve failure as a end result of moisture in the instrument media, which thickens the grease.
A direct-acting valve is your greatest option wherever potential in low-power environments. Not solely is the design much less advanced than an indirect-acting piloted valve, but additionally pilot mechanisms usually have vent ports that can admit moisture and contamination, leading to corrosion and permitting the valve to stick in the open position 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 circulate rates and so a pilot operation is critical. In this case, it is important to confirm that each one parts are rated to the same reliability rating because the solenoid.
Finally, since most remote places are by definition harsh environments, a solenoid installed there will need to have robust building and be capable of withstand and function at extreme temperatures while nonetheless sustaining the same reliability and security capabilities required in much less harsh environments.
When choosing a solenoid control valve for a remote operation, it’s possible to discover a valve that does not compromise efficiency and reliability to scale back energy demands. Look for a excessive FFR, easy dry armature design, great magnetic and warmth conductivity properties and robust construction.
Andrew Barko is the gross 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 provides cross-functional experience in application engineering and enterprise improvement to the oil, gasoline, petrochemical and energy industries and is certified as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the important thing account supervisor for the Energy Sector for IMI Precision Engineering. He offers expertise in new business growth 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).
Share