If a valve doesn’t operate, your course of doesn’t run, and that’s cash down the drain. Or worse, a spurious journey shuts the method down. Or worst of all, a valve malfunction results in a dangerous failure. Solenoid valves in oil and gas applications management the actuators that move giant process valves, including in emergency shutdown (ESD) techniques. The solenoid must exhaust air to enable the ESD valve to return to fail-safe mode each time sensors detect a dangerous process scenario. These valves should be quick-acting, sturdy and, above all, reliable to forestall downtime and the related losses that occur when a course of isn’t working.
And that is much more necessary for oil and gasoline operations the place there might be restricted energy obtainable, similar to distant wellheads or satellite offshore platforms. Here, solenoids face a double reliability problem. First, a failure to function correctly can not solely cause costly downtime, but a upkeep call to a distant location additionally takes longer and costs more than an area restore. Second, to reduce the demand for energy, many valve producers resort to compromises that truly cut back reliability. This is bad enough for course of valves, but for emergency shutoff valves and different safety instrumented techniques (SIS), it’s unacceptable.
Poppet valves are typically higher suited than spool valves for distant places as a outcome of they are less complex. For low-power applications, 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 reliable low-power solenoid
Many components 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 the most dependable valve.
High spring force is key to offsetting these forces and the friction they cause. However, in low-power purposes, most manufacturers need to compromise spring pressure to allow the valve to shift with minimal energy. The reduction in spring drive leads to a force-to-friction ratio (FFR) as little as 6, though the generally accepted security level is an FFR of 10.
Several elements of valve design play into the amount of friction generated. Optimizing each of those allows a valve to have larger spring force while still maintaining a excessive FFR.
For example, the valve operates by electromagnetism — a current stimulates the valve to open, permitting the media to circulate to the actuator and transfer the method valve. This media could additionally be air, but it could even be pure gas, instrument gasoline or even liquid. This is especially true in distant operations that should use whatever media is on the market. This means there is a trade-off between magnetism and corrosion. Valves by which the media is obtainable in contact with the coil must be manufactured 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 extremely magnetized material. As a result, there is not a residual magnetism after the coil is de-energized, which in turn allows faster response times. เกจวัดแรงดันน้ำ10บาร์ 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 beat the spring power. Integrating the valve and coil right into a single housing improves efficiency by stopping power loss, allowing for the use of a low-power coil, leading to much less energy consumption with out diminishing FFR. This built-in coil and housing design additionally reduces warmth, stopping 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 around the coil, nearly eliminates coil burnout concerns and protects process availability and safety.
Poppet valves are usually higher suited than spool valves for distant operations. The reduced complexity of poppet valves increases reliability by lowering sticking or friction points, and reduces the number of elements that can fail. Spool valves usually have large dynamic seals and heaps of require lubricating grease. Over time, particularly if the valves usually are not cycled, the seals stick and the grease hardens, leading to greater friction that should be overcome. There have been reports of valve failure as a result of moisture in the instrument media, which thickens the grease.
A direct-acting valve is your finest option wherever attainable in low-power environments. Not only is the design less complex than an indirect-acting piloted valve, but additionally pilot mechanisms typically have vent ports that may admit moisture and contamination, resulting in corrosion and allowing 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 pressure requirements.
Note that some larger actuators require excessive flow rates and so a pilot operation is necessary. In this case, it is essential to ascertain that every one elements are rated to the identical reliability ranking because the solenoid.
Finally, since most distant locations are by definition harsh environments, a solenoid put in there will must have strong construction and have the power to withstand and function at extreme temperatures whereas nonetheless sustaining the identical reliability and security capabilities required in much less harsh environments.
When deciding on a solenoid management valve for a distant operation, it is possible to discover a valve that does not compromise efficiency and reliability to reduce back energy calls for. Look for a excessive FFR, simple dry armature design, great magnetic and heat conductivity properties and sturdy building.
เกจ์วัดแรงดันลม is the sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion model parts for power operations. He provides cross-functional experience in application engineering and enterprise improvement to the oil, fuel, 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 supervisor for the Energy Sector for IMI Precision Engineering. He presents expertise in new enterprise improvement and buyer relationship administration to the oil, gasoline, petrochemical and power industries and is certified as a pneumatic specialist by the International Fluid Power Society (IFPS).
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