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 fuel functions control the actuators that move massive course of valves, together with in emergency shutdown (ESD) systems. The solenoid needs to exhaust air to allow the ESD valve to return to fail-safe mode whenever sensors detect a dangerous course of scenario. These valves should be quick-acting, durable and, above all, reliable to stop downtime and the associated losses that occur when a course of isn’t running.
And this is even more important for oil and fuel operations where there is restricted energy available, similar to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to operate accurately can not only trigger costly downtime, but a upkeep call to a remote location additionally takes longer and costs more than an area repair. Second, to reduce the demand for energy, many valve producers resort to compromises that really reduce reliability. This is bad enough for course of valves, however for emergency shutoff valves and other security instrumented techniques (SIS), it is unacceptable.
Poppet valves are usually better suited than spool valves for remote places because they are 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 performance of a solenoid valve. Friction, media flow, sticking of the spool, magnetic forces, remanence of electrical current and materials characteristics are all forces solenoid valve manufacturers have to beat to construct probably the most dependable valve.
High spring drive is vital to offsetting these forces and the friction they trigger. However, in low-power applications, most manufacturers have to compromise spring drive to allow the valve to shift with minimal energy. The reduction in spring force results in a force-to-friction ratio (FFR) as low as 6, though the commonly accepted security level is an FFR of 10.
Several parts of valve design play into the amount of friction generated. Optimizing each of these permits a valve to have greater spring pressure whereas nonetheless maintaining a high FFR.
For instance, the valve operates by electromagnetism — a current stimulates the valve to open, permitting the media to circulate to the actuator and move the method valve. This media may be air, however it might even be natural gasoline, instrument fuel or even liquid. This is especially true in remote operations that must use no matter media is on the market. This means there is a trade-off between magnetism and corrosion. Valves during which the media is out there in contact with the coil should 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 usage of highly magnetized material. As a result, there is no residual magnetism after the coil is de-energized, which in flip permits faster response occasions. 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 overcome the spring power. Integrating the valve and coil into a single housing improves effectivity by stopping vitality loss, permitting for the use of a low-power coil, resulting in less energy consumption without diminishing FFR. This integrated coil and housing design also reduces warmth, preventing spurious trips or coil burnouts. A dense, thermally environment friendly (low-heat generating) coil in a housing that acts as a warmth sink, designed with no air hole to entice heat around the coil, nearly eliminates coil burnout issues and protects course of availability and security.
Poppet valves are generally higher suited than spool valves for remote operations. The reduced complexity of poppet valves will increase reliability by lowering sticking or friction points, and decreases the variety of parts that may fail. Spool valves typically 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 must be overcome. There have been reviews of valve failure as a end result of moisture within the instrument media, which thickens the grease.
A direct-acting valve is the best choice wherever possible in low-power environments. Not solely is the design much less complex than an indirect-acting piloted valve, but in addition pilot mechanisms typically have vent ports that may admit moisture and contamination, resulting in 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 stress requirements.
Note that some larger actuators require excessive move rates and so a pilot operation is necessary. In ราคาpressuregauge , it could be very important confirm that each one elements are rated to the identical reliability rating as the solenoid.
Finally, since most remote locations are by definition harsh environments, a solenoid put in there must have robust construction and have the power to stand up to and function at extreme temperatures while still maintaining the same reliability and safety capabilities required in less harsh environments.
When deciding on a solenoid management valve for a remote operation, it’s possible to find a valve that does not compromise performance and reliability to reduce energy demands. Look for a high FFR, easy dry armature design, nice magnetic and heat conductivity properties and robust development.
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 power operations. He offers cross-functional expertise in software engineering and enterprise improvement to the oil, gasoline, petrochemical and energy industries and is licensed as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the key account manager for the Energy Sector for IMI Precision Engineering. He presents experience in new business growth and buyer relationship administration to the oil, fuel, petrochemical and power industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).
Share