If a valve doesn’t function, your process doesn’t run, and that’s cash down the drain. Or worse, a spurious trip shuts the method down. Or worst of all, a valve malfunction results in a harmful failure. Solenoid valves in oil and gasoline functions management the actuators that move giant course of valves, together with in emergency shutdown (ESD) techniques. The solenoid must exhaust air to allow the ESD valve to return to fail-safe mode whenever sensors detect a harmful course of scenario. These valves should be quick-acting, durable and, above all, dependable to forestall downtime and the related losses that happen when a course of isn’t working.
And that is even more necessary for oil and gas operations the place there could be limited energy obtainable, similar to distant wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to function appropriately cannot solely trigger costly downtime, however a upkeep name to a distant location also takes longer and prices more than a neighborhood repair. Second, to scale back the demand for power, many valve manufacturers resort to compromises that really cut back reliability. This is unhealthy enough for course of valves, but for emergency shutoff valves and different security instrumented techniques (SIS), it is unacceptable.
Poppet valves are usually higher suited than spool valves for distant areas because they’re less complicated. For low-power purposes, 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 factors can hinder the reliability and efficiency of a solenoid valve. Friction, media circulate, sticking of the spool, magnetic forces, remanence of electrical current and material traits are all forces solenoid valve manufacturers have to beat to construct essentially the most dependable valve.
High spring drive is vital to offsetting these forces and the friction they cause. However, in low-power purposes, most producers need to compromise spring drive to permit the valve to shift with minimal power. The discount in spring force ends in a force-to-friction ratio (FFR) as low as 6, though the commonly accepted security level is an FFR of 10.
Several components of valve design play into the amount of friction generated. Optimizing every of those permits a valve to have higher spring drive whereas nonetheless sustaining a excessive FFR.
For example, the valve operates by electromagnetism — a current stimulates the valve to open, allowing the media to circulate to the actuator and transfer the method valve. This media may be air, however it might also be natural gasoline, instrument gas and even liquid. This is very true in remote operations that should use whatever media is out there. This means there’s a trade-off between magnetism and corrosion. Valves in which the media comes in contact with the coil must be made of 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 ไดอะแฟรม , there isn’t a residual magnetism after the coil is de-energized, which in turn permits faster response times. This design additionally protects reliability by preventing contaminants in 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 overcome the spring energy. Integrating the valve and coil right into a single housing improves effectivity by preventing power loss, permitting for using a low-power coil, resulting in less power consumption with out diminishing FFR. This integrated coil and housing design additionally reduces warmth, preventing spurious journeys or coil burnouts. A dense, thermally environment friendly (low-heat generating) coil in a housing that acts as a heat sink, designed with no air hole to lure warmth across the coil, virtually eliminates coil burnout issues and protects process availability and safety.
Poppet valves are generally better suited than spool valves for remote operations. The reduced complexity of poppet valves increases reliability by reducing sticking or friction factors, and reduces the variety of components that may fail. Spool valves often have giant dynamic seals and tons of require lubricating grease. Over time, particularly if the valves aren’t cycled, the seals stick and the grease hardens, resulting in greater friction that should be overcome. There have been reviews of valve failure due to moisture in the instrument media, which thickens the grease.
A direct-acting valve is the best choice wherever possible in low-power environments. Not only is the design much less complicated than an indirect-acting piloted valve, but also pilot mechanisms often 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 minimum stress requirements.
Note that some bigger actuators require excessive flow charges and so a pilot operation is critical. In this case, you will need to verify that each one components are rated to the same reliability ranking because the solenoid.
Finally, since most remote locations are by definition harsh environments, a solenoid installed there should have sturdy building and be capable of face up to and operate at extreme temperatures whereas nonetheless maintaining the identical reliability and security capabilities required in less harsh environments.
When selecting a solenoid control valve for a distant operation, it’s possible to discover a valve that does not compromise efficiency and reliability to reduce back power demands. Look for a excessive FFR, easy dry armature design, nice magnetic and heat conductivity properties and robust development.
Andrew Barko is the sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion model elements for power operations. He presents cross-functional expertise in application engineering and enterprise growth to the oil, gas, 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 manager for the Energy Sector for IMI Precision Engineering. He offers experience in new enterprise improvement and customer relationship management to the oil, gasoline, petrochemical and energy industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).