Solenoid valve reliability in lower power operations

If a valve doesn’t operate, your course of 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 dangerous failure. Solenoid valves in oil and fuel purposes management the actuators that transfer large process 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 process state of affairs. These valves have to be quick-acting, durable and, above all, dependable to stop downtime and the associated losses that occur when a process isn’t operating.
And this is much more essential for oil and fuel operations where there could be restricted power out there, similar to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability problem. First, a failure to function correctly can not solely trigger costly downtime, however a maintenance name to a remote location additionally takes longer and costs more than an area restore. Second, to reduce back the demand for energy, many valve producers resort to compromises that really scale back reliability. This is unhealthy sufficient for process valves, however for emergency shutoff valves and other safety instrumented systems (SIS), it’s unacceptable.
Poppet valves are generally better suited than spool valves for distant areas as a outcome of they are much 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 factors can hinder the reliability and performance of a solenoid valve. Friction, media circulate, sticking of the spool, magnetic forces, remanence of electrical current and materials characteristics are all forces solenoid valve manufacturers have to overcome to build the most reliable valve.
High spring pressure is vital to offsetting these forces and the friction they cause. However, in low-power applications, most manufacturers should compromise spring force to permit the valve to shift with minimal energy. The discount in spring force leads to a force-to-friction ratio (FFR) as little as 6, although the commonly accepted security level is an FFR of 10.
Several elements of valve design play into the quantity of friction generated. Optimizing every of those allows a valve to have larger spring drive while nonetheless sustaining a excessive FFR.
For instance, the valve operates by electromagnetism — a current stimulates the valve to open, allowing the media to flow to the actuator and transfer the process valve. This media may be air, but it could even be pure fuel, instrument gas and even liquid. This is very true in remote operations that must use whatever media is on the market. This means there’s a trade-off between magnetism and corrosion. Valves by which the media comes in contact with the coil should be made from anticorrosive materials, which have poor magnetic properties. A valve design that isolates the media from the coil — a dry armature — allows the utilization of highly magnetized materials. As a result, there is no residual magnetism after the coil is de-energized, which in flip allows faster response instances. 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 beat the spring energy. Integrating the valve and coil right into a single housing improves efficiency by preventing power loss, allowing for the use of a low-power coil, resulting in less energy consumption without diminishing FFR. This integrated coil and housing design additionally reduces warmth, stopping 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 gap to entice warmth around the coil, just about eliminates coil burnout issues and protects process availability and safety.
Poppet valves are generally better suited than spool valves for distant operations. The lowered complexity of poppet valves increases reliability by reducing sticking or friction points, and reduces the number of elements that can fail. Spool valves typically have giant dynamic seals and lots of require lubricating grease. Over time, particularly if the valves usually are not cycled, the seals stick and the grease hardens, resulting in higher friction that should be overcome. There have been เกจวัดแรงดันราคา of valve failure due to moisture in the instrument media, which thickens the grease.
A direct-acting valve is the solely option wherever potential in low-power environments. Not only is the design less complicated than an indirect-acting piloted valve, but in addition 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 particularly designed to shift the valves with zero minimal stress requirements.
Note that some bigger actuators require high circulate rates and so a pilot operation is critical. In this case, you will want to ascertain that each one elements are rated to the same reliability score because the solenoid.
Finally, since most distant locations are by definition harsh environments, a solenoid installed there must have sturdy building and have the flexibility to face up to and operate at excessive temperatures whereas nonetheless maintaining the same reliability and security capabilities required in much 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 efficiency and reliability to reduce energy calls for. Look for a excessive FFR, easy dry armature design, nice magnetic and heat conductivity properties and sturdy construction.
Andrew Barko is the 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 offers cross-functional experience in software engineering and enterprise growth to the oil, gasoline, petrochemical and power industries and is certified as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the key account supervisor for the Energy Sector for IMI Precision Engineering. He provides experience in new business growth and customer relationship management to the oil, gas, petrochemical and energy industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).
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