Expo Releases a Deluge of Valve Info
In the case of a couple of manufacturers exhibiting at the 2007 Air Conditioning, Heating, Refrigerating Exposition (AHR Expo), opening those kits unleashed a flood of valve-related technology. Those once basic components have become a whole lot more complex.
Danfoss (www.danfoss.com) introduced the Universal TR6 thermostatic expansion valve, designed to increase the efficiency of older air conditioners and heat pumps regardless of the manufacturer, and reduce energy costs.
The company said the TR6 retrofit could boost system efficiency 10-15 percent on older equipment, depending on the age and capacity of the system.
“Research has demonstrated that a thermostatic expansion valve offers the most timely, most cost efficient, and least risky method to regulate refrigerant flow and increase the efficiency of older residential air conditioning systems,” said Mark White, aftermarket business de-velopment manager at Danfoss.
Temperature and pressure sensors open or close the diaphragm as needed, as the TR6 meters refrigerant flow to maintain proper gas saturation in the coil. An internal check valve, adjustable superheat, and adaptable inlet and outlet ports allow the contractor to install the valve after selecting the refrigerant, tonnage, and connection type. The TR6 valve fits Aeroquip, Chatliff, and a variety of other connections, the company said.
Parker Hannifin-Sporlan (www.parker.com) introduced the Brass (M) E35S1 Series solenoid valve, featuring a corrosion-resistant brass body and stainless steel bolts. The valve’s large main piston allows full-open operation at low pressure drop. When the coil is de-energized, a strong spring provides shutoff force even at low- and no-flow conditions, the company said.
The company’s new ESX step motor expansion valve provides flow control for supermarket refrigeration, air conditioning, and heat pump applications, as well as self-contained refrigeration systems. “The exceptional capacity range makes it an ideal choice for more complex systems that use variable compressor capacity or multiple evaporators,” the company said.
The ESX combines a proportional expansion device, shutoff, and electronic positioning into one valve. It also features a hermetic design and includes a removable dry stator, which rotates to fit into the required cabinet space.
The unipolar step motor is designed to work with Sporlan ESX interface boards or controllers. This 500-step biflow valve provides tight shutoff capability, which can eliminate the need for a liquid line solenoid valve in high-efficiency air conditioners and supermarket refrigeration, the company said. Sporlan’s electronic suction control valves, the CDS-9, -16, and -17, respond to signals in an electronic controller and sensor, then regulate the proper temperature in the evaporator.
Standard 12-V DC step motors regulate the valves. These valves are said be able to replace mechanical EPR valves, suction stop solenoid valves, and conventional thermostats. In most applications, the CDS-9, -16, and CDS-17 valves can control multiple evaporators.
SDR Series electric discharge bypass valves can be interfaced with direct digital controls (DDCs) or other building management systems, eliminating the need for cylinder unloaders. And, they can be set to automatically maintain a desired minimum evaporating temperature regardless of the decrease in evaporator load, the company said. A controller that rotates a step motor electronically modulates the valves.
Sporlan’s Temperature Control Board (TCB) is a single-point controller that senses temperature, calculates valve position, and drives the step motor to the position needed to control a CDS or SDR valve. The TCB can also be used as an interface to an external DDC or PID controller.
The SMA-12 is a useful accessory to step motor valves. This diagnostic tool is connected to the wires in the valve cable and troubleshoots at four different step rates. In case of controller failure, the SMA-12 can be set manually to open or close the valve, or step the valve to any position. Two 9-V alkaline cells extend the life of the unit.
Parker Hannifin-Sporlan also showcased the Kelvin electronic valve controller, a “set-and-forget” electronic superheat control. It is set by the manufacturer to the tested, optimum superheat. Field changes may be performed with the approval and support of the manufacturer through the use of proprietary software.
The Kelvin can control all Sporlan EEVs as part of a system that consists of the Kelvin electronic controller, one or two temperature sensors, a Sporlan electric expansion valve, and a pressure transducer, the company said. The Kelvin may be DIN rail or screw mounted in the enclosed condensing unit, for packaged equipment, or in the control area of the evaporator or air-handling unit.
Publication date: 02/19/2007