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 leads to a harmful failure. Solenoid valves in oil and fuel functions management the actuators that transfer large 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 each time sensors detect a dangerous process situation. These valves should be quick-acting, durable and, above all, reliable to forestall downtime and the associated losses that happen when a course of isn’t running.
And that is much more necessary for oil and gasoline operations the place there’s limited energy out there, similar to distant wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to operate appropriately can’t solely trigger costly downtime, but a upkeep call to a remote location also takes longer and costs more than a local repair. Second, to reduce the demand for energy, many valve producers resort to compromises that actually reduce reliability. This is dangerous enough for course of valves, but for emergency shutoff valves and other safety instrumented methods (SIS), it’s unacceptable.
Poppet valves are typically higher suited than spool valves for distant areas as a end result of they are much less advanced. For low-power applications, 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 dependable low-power solenoid
Many factors can hinder the reliability and efficiency of a solenoid valve. เพรสเชอร์เกจลม , media move, sticking of the spool, magnetic forces, remanence of electrical current and materials characteristics are all forces solenoid valve manufacturers have to beat to construct essentially the most reliable valve.
High spring force is key to offsetting these forces and the friction they trigger. However, in low-power functions, most producers have to compromise spring drive to allow the valve to shift with minimal power. The discount in spring drive ends in a force-to-friction ratio (FFR) as little as 6, although the widely accepted security degree is an FFR of 10.
Several parts of valve design play into the quantity of friction generated. Optimizing every of these allows a valve to have greater spring drive whereas nonetheless maintaining a high FFR.
For example, the valve operates by electromagnetism — a present stimulates the valve to open, allowing the media to flow to the actuator and move the method valve. This media could also be air, however it might even be natural fuel, instrument gas and even liquid. This is particularly true in remote operations that must use whatever media is available. This means there is a trade-off between magnetism and corrosion. Valves in which the media comes in contact with the coil should be made from anticorrosive supplies, which have poor magnetic properties. A valve design that isolates the media from the coil — a dry armature — allows using highly magnetized materials. As a result, there is not any residual magnetism after the coil is de-energized, which in turn allows quicker response times. This design additionally protects reliability by preventing contaminants in 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 strength. Integrating the valve and coil into a single housing improves efficiency by preventing power loss, allowing for using a low-power coil, resulting in less energy consumption without diminishing FFR. This integrated coil and housing design also reduces heat, preventing spurious trips or coil burnouts. A dense, thermally efficient (low-heat generating) coil in a housing that acts as a warmth sink, designed with no air gap to lure heat across the coil, nearly eliminates coil burnout considerations and protects process availability and safety.
Poppet valves are usually better suited than spool valves for remote 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 typically have giant dynamic seals and lots of require lubricating grease. Over time, especially if the valves aren’t cycled, the seals stick and the grease hardens, resulting in larger friction that have to be overcome. There have been reports of valve failure because of moisture in the instrument media, which thickens the grease.
A direct-acting valve is the solely option wherever attainable in low-power environments. Not solely is the design much less advanced than an indirect-acting piloted valve, but also pilot mechanisms typically have vent ports that may admit moisture and contamination, resulting in corrosion and permitting the valve to stick in the open place even when de-energized. Also, direct-acting solenoids are specifically designed to shift the valves with zero minimum stress necessities.
Note that some larger actuators require high move rates and so a pilot operation is important. In this case, you will want to verify that each one parts are rated to the identical reliability ranking as the solenoid.
Finally, since most distant places are by definition harsh environments, a solenoid installed there will have to have sturdy building and be capable of stand up to and operate at excessive temperatures whereas nonetheless sustaining the identical reliability and safety capabilities required in less harsh environments.
When deciding on a solenoid management valve for a distant operation, it’s attainable to discover a valve that doesn’t compromise performance and reliability to reduce energy demands. Look for a excessive FFR, easy dry armature design, nice magnetic and warmth 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 model components for energy operations. He provides cross-functional experience in application engineering and business development 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 important thing account manager for the Energy Sector for IMI Precision Engineering. He presents experience in new business improvement and buyer relationship administration to the oil, gas, petrochemical and energy industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).
Share