If a valve doesn’t function, your process doesn’t run, and that is cash down the drain. Or worse, a spurious trip shuts the process down. Or worst of all, a valve malfunction results in a dangerous failure. Solenoid valves in oil and fuel applications control the actuators that move large 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 each time sensors detect a dangerous course of scenario. These valves must be quick-acting, durable and, above all, reliable to stop downtime and the associated losses that occur when a course of isn’t running.
And that is even more necessary for oil and gas operations the place there might be limited power obtainable, corresponding to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability problem. First, a failure to operate accurately can’t only cause costly downtime, but a maintenance call to a remote location also takes longer and costs greater than an area repair. Second, to scale back the demand for energy, many valve producers resort to compromises that really scale back reliability. This is bad enough for course of valves, however for emergency shutoff valves and other safety instrumented methods (SIS), it’s unacceptable.
Poppet valves are usually better suited than spool valves for remote places as a outcome of they are less complicated. For low-power purposes, 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 elements can hinder the reliability and performance of a solenoid valve. Friction, media move, sticking of the spool, magnetic forces, remanence of electrical current and material traits are all forces solenoid valve manufacturers have to overcome to construct probably the most reliable valve.
High spring drive is vital 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 power. The reduction in spring pressure results in a force-to-friction ratio (FFR) as low as 6, though the widely accepted security level is an FFR of 10.
Several parts of valve design play into the quantity of friction generated. Optimizing each of those permits a valve to have greater spring pressure while nonetheless sustaining a high FFR.
For example, the valve operates by electromagnetism — a current stimulates the valve to open, allowing the media to flow to the actuator and move the method valve. This media may be air, however it may even be pure gas, instrument gas and even liquid. This is especially true in distant operations that must use no matter media is available. This means there is a trade-off between magnetism and corrosion. Valves during which the media comes in contact with the coil must be manufactured from anticorrosive materials, 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 no residual magnetism after the coil is de-energized, which in flip allows faster response instances. This design also protects reliability by stopping contaminants within the media from reaching the inside workings of the valve.
เพรสเชอร์เกจ4นิ้ว 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, permitting for the utilization of a low-power coil, leading to much less power consumption without diminishing FFR. This built-in coil and housing design additionally reduces warmth, stopping 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, just about eliminates coil burnout considerations and protects process availability and security.
Poppet valves are typically higher suited than spool valves for distant operations. The decreased complexity of poppet valves will increase reliability by reducing sticking or friction factors, and reduces the number of components that can fail. Spool valves typically have massive dynamic seals and heaps of require lubricating grease. Over time, especially if the valves are not cycled, the seals stick and the grease hardens, leading to greater friction that have to be overcome. There have been stories of valve failure as a result of moisture within 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 much less complex than an indirect-acting piloted valve, but also pilot mechanisms typically have vent ports that may admit moisture and contamination, resulting in corrosion and allowing the valve to stick within the open place even when de-energized. Also, direct-acting solenoids are particularly designed to shift the valves with zero minimum pressure requirements.
Note that some larger actuators require excessive move rates and so a pilot operation is important. In this case, you will need to confirm that each one parts are rated to the same reliability ranking as the solenoid.
Finally, since most distant places are by definition harsh environments, a solenoid put in there must have sturdy building and be capable of face up to and function at excessive temperatures while still sustaining the same reliability and security capabilities required in much less harsh environments.
When deciding on a solenoid management valve for a remote operation, it’s attainable to find a valve that doesn’t compromise efficiency and reliability to scale back power calls for. Look for a high FFR, easy dry armature design, great magnetic and heat conductivity properties and sturdy building.
Andrew Barko is the sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion brand parts for power operations. He presents cross-functional experience in software engineering and business improvement to the oil, gas, petrochemical and power 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 provides experience in new business growth and buyer relationship management to the oil, gas, petrochemical and power industries and is certified as a pneumatic specialist by the International Fluid Power Society (IFPS).