Solenoid valve reliability in lower energy operations

If a valve doesn’t function, your course of doesn’t run, and that’s cash down the drain. Or worse, a spurious journey shuts the process down. Or worst of all, a valve malfunction leads to a dangerous failure. Solenoid valves in oil and fuel applications management the actuators that transfer large process valves, together with in emergency shutdown (ESD) techniques. The solenoid must exhaust air to enable the ESD valve to return to fail-safe mode every time sensors detect a dangerous course of state of affairs. These valves must be quick-acting, sturdy and, above all, reliable to forestall downtime and the associated losses that occur when a course of isn’t working.
And this is much more necessary for oil and gas operations where there is restricted energy out there, such as remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to function accurately cannot solely trigger expensive downtime, however a maintenance call to a remote location also takes longer and prices more than an area restore. Second, to reduce the demand for energy, many valve manufacturers resort to compromises that truly scale back reliability. This is bad sufficient for process valves, however for emergency shutoff valves and different safety instrumented systems (SIS), it is unacceptable.
Poppet valves are typically higher suited than spool valves for distant places as a result of they’re much 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 components can hinder the reliability and performance of a solenoid valve. ขนาดpressuregauge , media flow, sticking of the spool, magnetic forces, remanence of electrical present and material traits are all forces solenoid valve manufacturers have to overcome to build the most reliable valve.
High spring pressure is essential to offsetting these forces and the friction they cause. However, in low-power purposes, most producers have to compromise spring pressure to permit the valve to shift with minimal energy. The discount in spring drive leads to a force-to-friction ratio (FFR) as low as 6, although the commonly accepted safety degree is an FFR of 10.
Several elements of valve design play into the amount of friction generated. Optimizing every of those permits a valve to have higher spring force whereas nonetheless maintaining 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 move the process valve. This media may be air, but it could also be natural gas, instrument gas or even liquid. This is very true in distant operations that should use no matter 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 must be made from anticorrosive materials, which have poor magnetic properties. A valve design that isolates the media from the coil — a dry armature — permits using extremely magnetized material. As a end result, there isn’t a residual magnetism after the coil is de-energized, which in flip permits faster response occasions. This design additionally protects reliability by stopping contaminants in the media from reaching the internal 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 strength. Integrating the valve and coil right into a single housing improves efficiency by stopping vitality loss, permitting for the use of a low-power coil, leading to much less power consumption without diminishing FFR. This integrated coil and housing design also reduces heat, stopping spurious journeys or coil burnouts. A dense, thermally efficient (low-heat generating) coil in a housing that acts as a warmth sink, designed with no air hole to entice warmth around the coil, just about eliminates coil burnout considerations and protects course of availability and safety.
Poppet valves are usually better suited than spool valves for remote operations. The decreased complexity of poppet valves increases reliability by reducing sticking or friction points, and reduces the number of components that may fail. Spool valves usually have giant dynamic seals and plenty of require lubricating grease. Over time, especially if the valves are not cycled, the seals stick and the grease hardens, leading to higher friction that must be overcome. There have been reviews of valve failure because of moisture in the instrument media, which thickens the grease.
A direct-acting valve is the only option wherever attainable in low-power environments. Not only is the design less complex than an indirect-acting piloted valve, but also pilot mechanisms usually have vent ports that can admit moisture and contamination, leading to corrosion and permitting the valve to stay in the open place even when de-energized. Also, direct-acting solenoids are particularly designed to shift the valves with zero minimal strain requirements.
Note that some larger actuators require high flow rates and so a pilot operation is critical. In this case, it is very important ascertain that every one parts are rated to the same reliability ranking as the solenoid.
Finally, since most distant places are by definition harsh environments, a solenoid installed there will have to have sturdy development and be succesful of withstand and operate at extreme temperatures while nonetheless maintaining the identical reliability and safety capabilities required in less harsh environments.
When selecting a solenoid control valve for a remote operation, it is attainable to find a valve that does not compromise performance and reliability to scale back power demands. Look for a excessive FFR, simple dry armature design, great magnetic and heat conductivity properties and strong 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 parts for vitality operations. He provides cross-functional expertise in software engineering and business development to the oil, fuel, petrochemical and power industries and is certified as a pneumatic Specialist by the International Fluid Power Society (IFPS).
Collin Skufca is the necessary thing account manager for the Energy Sector for IMI Precision Engineering. He offers experience in new business improvement and buyer relationship management to the oil, gasoline, petrochemical and power industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).

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