If a valve doesn’t function, your course of doesn’t run, and that is money down the drain. Or worse, a spurious trip shuts the process down. Or worst of all, a valve malfunction results in a harmful failure. Solenoid valves in oil and gasoline applications control the actuators that move massive course of valves, including in emergency shutdown (ESD) systems. The solenoid needs to exhaust air to allow the ESD valve to return to fail-safe mode every time sensors detect a harmful course of situation. These valves should be quick-acting, durable and, above all, reliable to prevent downtime and the associated losses that occur when a course of isn’t working.
And this is even more necessary for oil and gas operations where there’s restricted energy obtainable, similar to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to operate correctly cannot only cause pricey downtime, but a maintenance name to a remote location additionally takes longer and prices greater than a local repair. Second, to reduce back the demand for energy, many valve producers resort to compromises that actually scale back reliability. This is bad enough for course of valves, but for emergency shutoff valves and different safety instrumented systems (SIS), it’s unacceptable.
Poppet valves are usually better suited than spool valves for remote locations because they’re 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 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 present and material traits are all forces solenoid valve producers have to overcome to construct the most reliable valve.
High spring drive is essential to offsetting these forces and the friction they trigger. However, in low-power functions, most manufacturers need to compromise spring force to allow the valve to shift with minimal power. The discount in spring pressure results in a force-to-friction ratio (FFR) as little as 6, although the widely accepted security degree 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 drive while nonetheless sustaining a high FFR.
For instance, the valve operates by electromagnetism — a current stimulates the valve to open, permitting the media to move to the actuator and transfer the method valve. This media may be air, but it might even be pure gasoline, instrument fuel and even liquid. This is very true in distant operations that should use no matter media is on the market. This means there’s a trade-off between magnetism and corrosion. เกจวัดแก๊สlpg in which the media is available 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 using extremely magnetized materials. As a end result, there is no residual magnetism after the coil is de-energized, which in turn allows quicker response occasions. This design additionally protects reliability by preventing contaminants within the media from reaching the internal 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 energy loss, allowing for the use of a low-power coil, resulting in much less energy consumption with out diminishing FFR. This integrated coil and housing design additionally reduces heat, preventing 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 gap to trap heat across the coil, nearly eliminates coil burnout concerns and protects process availability and safety.
Poppet valves are typically better suited than spool valves for remote operations. The reduced complexity of poppet valves increases reliability by lowering sticking or friction points, and decreases the variety of parts that can fail. Spool valves typically have giant dynamic seals and many require lubricating grease. Over time, especially if the valves aren’t cycled, the seals stick and the grease hardens, leading to larger friction that must be overcome. There have been stories of valve failure as a outcome of moisture within the instrument media, which thickens the grease.
A direct-acting valve is the finest choice wherever attainable in low-power environments. Not solely is the design less advanced than an indirect-acting piloted valve, but in addition pilot mechanisms typically have vent ports that can admit moisture and contamination, leading to 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 minimal stress necessities.
Note that some larger actuators require high move rates and so a pilot operation is necessary. In this case, it could be very important confirm that every one elements are rated to the identical reliability ranking because the solenoid.
Finally, since most remote areas are by definition harsh environments, a solenoid put in there should have robust construction and be in a position to face up to and operate at excessive temperatures whereas nonetheless maintaining the same reliability and security capabilities required in less harsh environments.
When selecting a solenoid control valve for a remote operation, it’s potential to discover a valve that doesn’t compromise efficiency and reliability to reduce power demands. Look for a high FFR, easy dry armature design, great magnetic and warmth conductivity properties and robust development.
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 power operations. He offers cross-functional expertise in application engineering and business development to the oil, gas, 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 presents expertise in new business development and buyer relationship administration to the oil, fuel, petrochemical and energy industries and is certified as a pneumatic specialist by the International Fluid Power Society (IFPS).