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 leads to a harmful failure. Solenoid valves in oil and gas applications management the actuators that transfer massive process valves, including in emergency shutdown (ESD) methods. The solenoid must exhaust air to allow the ESD valve to return to fail-safe mode whenever sensors detect a harmful course of situation. These valves have to be quick-acting, durable and, above all, dependable to forestall downtime and the associated losses that happen when a process isn’t operating.
And that is even more necessary for oil and fuel operations where there’s restricted energy out there, similar to remote wellheads or satellite offshore platforms. Here, solenoids face a double reliability challenge. First, a failure to function accurately can’t only cause costly downtime, however a maintenance call to a distant location also takes longer and costs greater than a neighborhood restore. Second, to cut back the demand for power, many valve producers resort to compromises that truly reduce reliability. This is unhealthy sufficient for process valves, but for emergency shutoff valves and different security instrumented systems (SIS), it is unacceptable.
Poppet valves are generally better suited than spool valves for remote areas as a outcome of they are less complicated. 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 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 present and materials traits are all forces solenoid valve manufacturers have to beat to construct the most reliable valve.
High spring drive is key to offsetting these forces and the friction they cause. However, in low-power functions, most manufacturers have to compromise spring force to permit the valve to shift with minimal power. The reduction in spring pressure leads to a force-to-friction ratio (FFR) as low as 6, though the widely accepted safety level is an FFR of 10.
Several elements of valve design play into the amount of friction generated. Optimizing every of those allows a valve to have greater spring pressure while still sustaining a excessive FFR.
For instance, the valve operates by electromagnetism — a present stimulates the valve to open, allowing the media to circulate to the actuator and move the method valve. This media may be air, however it might even be pure fuel, instrument gasoline or even liquid. This is especially true in distant operations that must use whatever media is on the market. This means there is a trade-off between magnetism and corrosion. Valves by which the media comes in contact with the coil should 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 use of extremely magnetized materials. As a result, there isn’t a residual magnetism after the coil is de-energized, which in flip permits quicker response instances. This design additionally protects reliability by preventing contaminants within the media from reaching the inside workings of the valve.
Another factor 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 effectivity by stopping energy loss, allowing for the utilization of a low-power coil, leading to less power consumption without diminishing FFR. This built-in coil and housing design additionally reduces warmth, stopping spurious journeys or coil burnouts. A dense, thermally efficient (low-heat generating) coil in a housing that acts as a heat sink, designed with no air hole to trap heat around the coil, nearly eliminates coil burnout concerns and protects course of availability and security.
Poppet valves are generally higher suited than spool valves for remote operations. The reduced complexity of poppet valves increases reliability by reducing sticking or friction factors, and reduces the variety of elements that can fail. Spool valves typically have giant dynamic seals and heaps of require lubricating grease. Over time, especially if the valves aren’t cycled, the seals stick and the grease hardens, leading to greater friction that should be overcome. There have been reviews of valve failure because of moisture in the instrument media, which thickens the grease.
เกจวัดความดันน้ำ -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 also pilot mechanisms usually have vent ports that can admit moisture and contamination, leading to corrosion and permitting 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 strain requirements.
Note that some larger actuators require excessive move charges and so a pilot operation is important. In this case, it may be very important confirm that all elements are rated to the identical reliability ranking as the solenoid.
Finally, since most distant places are by definition harsh environments, a solenoid installed there should have sturdy building and be ready to face up to and operate at extreme temperatures whereas still maintaining the same reliability and safety capabilities required in much less harsh environments.
When selecting a solenoid control valve for a distant operation, it is potential to discover a valve that doesn’t compromise efficiency and reliability to reduce power demands. Look for a excessive FFR, easy dry armature design, nice magnetic and warmth conductivity properties and strong construction.
Andrew Barko is the gross sales engineer for the Energy Sector of IMI Precision Engineering, makers of IMI Norgren, IMI Maxseal and IMI Herion brand components for power operations. He provides cross-functional expertise in utility engineering and business improvement 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 key account manager for the Energy Sector for IMI Precision Engineering. He offers experience in new enterprise development and customer relationship administration to the oil, gasoline, petrochemical and power industries and is licensed as a pneumatic specialist by the International Fluid Power Society (IFPS).