A new pneumatic valve on the market this month proposes to save users up to 30% in compressed air compared to traditional directional control valves. A unique spool configuration and on-board microelectronics help achieve this savings by recycling compressed air. (See a video about this valve here.)
Launched by Nexmatix, based in St. Louis, the new valves are designed for use in the majority of applications employing double-acting cylinders. The highest savings will be seen in applications with any of the following: long air line lengths (greater than 3 ft), fast cycle times (less than 4 sec), those operating multiple hours per day, or those with large air volume (large diameter or long stroke cylinders).
Nexmatix valves have been tested by Oak Ridge National Laboratory, which has reported on the feasibility and testing of the lightweight, energy-efficient, additive manufactured pneumatic control valve. The lab’s results confirmed that Nexmatix valves “are as energy efficient as stated.” The report went on to say “measuring air consumption per work completed, the Nexmatix valve was as much as 85% better than” the valve to which it was compared.
According to Victoria Gonzalez, Nexmatix CEO, “Our mission is to lower customers’ cost by delivering technology that reduces compressed air, minimizes inventory and delivers relevant data to help manage maintenance of pneumatic systems. Nexmatix is efficient pneumatics, intelligently simple.”
Conventional 5/2 and 5/3 valves actuate or extend a double-acting cylinder by connecting supply pressure to one side of the cylinder while simultaneously exhausting the other side. To reverse or retract the motion of the cylinder, the connection is simply reversed: the side of the cylinder that was exhausted is connected to supply and the pressurized side is now exhausted. In this situation, all of the compressed air used to produce actuation is lost on each stroke.
“Conventional directional control valves exhaust 50% of air used during every valve cycle, effectively creating the largest compressed air leak in the plant,” Gonzalez said. “Nexmatix valves recycle compressed air using a unique body and spool design, saving manufacturers 10 to 45% of compressed air.”
Nexmatix valves employ proprietary technology that briefly connects the two cylinder ports before exhausting the pressurized side. This effectively precharges the port before it is connected to supply, saving on average, 30% of the compressed air. In milliseconds, the two sides equilibrate, recycling the compressed air left in the pressurized lines. Afterward, a small amount of air is vented and the source air completes the cycle.
For a 5/3 pneumatic valve, the center position behavior or exhaust-centered, is maintained during power down.
Nexmatix has launched ISO 15407-1 and 15407-2 26-mm valves and ISO manifolds. Later this year, the company expects to launch an 18-mm size and ISO 5599-1 and 5599-2 Size 1. Forthcoming Nexmatix technology, due for release in late 2016, will provide similar compressed air savings when used with single-acting cylinders.
Nexmatix valves are developed as plug-and-play for existing ISO valves, offering a seamless changeover, with no programming or wiring changes required by the end-users.
The company is targeting industrial, food and packaging manufacturers. In addition to the research done at Oak Ridge, it is currently implementing test manifolds at various industrial sites. Several small tests using in-line flow meters to measure air showed a 28.9% reduction in compressed air used when comparing a manifold of conventional valves with a similar manifold of Nexmatix valves, Gonzalez said.
The company got its start at the university level, with research that was done at Vanderbilt University by Dr. Michael Goldfarb. Nexmatix negotiated an exclusive world-wide license to the pneumatic valve technology in 2012 and developed the technology by incorporating it into conventional valves with National Science Foundation grant money. In March 2014, Nexmatix decided to launch its own line of ISO valves to maximize the effectiveness of the technology.
As Gonzalez put it, the technology is now in place to create these valves and it’s time to exploit a seemingly obvious source of energy savings.
“Nexmatix technology has been made more feasible by the recent availability of ultra-compact, low-cost microcontroller technology, which enable our valves to provide significant compressed gas savings without compromising on cost, compatibility, or performance. The value proposition of Nexmatix technology is further strengthened by the growing interest in reducing environmental impact in the industrial sector,” Gonzalez said. “The Nexmatix valve is a 21st century concept—enabled by 21st century technology, and created in the context of 21st century sensibilities.”