Model: NL-PZF-2

The problem

The electronic expansion valve is the throttling throat of an inverter air conditioner: when the flow characteristic drifts, cooling capacity, energy efficiency and superheat control all suffer. Measuring open-pulse, port leakage and operating pressure differential by hand with a nitrogen bottle and a digital gauge takes tens of minutes per valve and never produces a complete flow-versus-pulse curve; T-type and U-type valves on one mixed line make changeover slower still.

Capability

Two stations (one used when life testing) finish a valve within 60 seconds, hand loaded, one clamping per test item. Five tests are covered: internal leakage, flow characteristic, maximum operating pressure differential forward and reverse, and fatigue. For the flow characteristic the valve inlet receives 0.1MPa nitrogen with the outlet open to atmosphere; at 500 pulses five points are measured in each direction with every flow-versus-pulse value recorded. For the open pulse the valve is driven fully closed at DC12V with the specified 1-2 phase excitation at 83.3PPS; nitrogen at 1MPa enters the inlet and the valve is opened one pulse at a time while the software automatically captures the flow-break point - the pulse count there is the open pulse. Port leakage is read directly at 1MPa with the valve fully closed. Instrumentation meets the standard: digital pressure gauge 0-6MPa within 0.5 percent, digital gas flow meter 0-10000L/H within 2 percent, voltage and current within 0.5 percent. Pressure, flow and pulse count are sampled live and sudden changes are identified automatically. Test products, methods and reports are stored in a database, printable and programmable, compatible with Office.

Key specifications

• Application: comprehensive performance of electronic expansion valves
• Stations: 2 (1 used during life testing)
• Cycle: within 60 seconds per valve, hand loaded
• Tests: internal leakage, flow characteristic, forward/reverse max operating differential, fatigue
• Flow characteristic: 0.1MPa nitrogen inlet, open outlet, 5 points forward and reverse at 500 pulses
• Open pulse: DC12V, 1-2 phase excitation, 83.3PPS, 1-pulse stepping with automatic breakpoint capture
• Leakage: 1MPa nitrogen at fully closed state, flow sensor at outlet
• Pressure gauge: 0-6MPa digital, better than 0.5 percent
• Gas flow meter: 0-10000L/H digital, better than 2 percent
• Voltage and current: digital, better than 0.5 percent
• Drive: pulse count freely settable, excitation and frequency settable, pressure ratio adjustable
• Gas supply: clean high-purity nitrogen at 6MPa or above

Applications

Outgoing inspection and sampling of electronic expansion valves on inverter AC lines; flow characteristic and life type testing at valve plants; incoming verification of full-pulse count, open pulse and leakage by appliance makers; development testing in refrigeration valve laboratories

About the manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd provides non-standard customization, drawing confirmation, factory acceptance, on-site installation and commissioning, operation training and long-term technical service; 12-month warranty and long-term spare parts supply. Tel: 0760-88500902 / 13416787649. Web: en.zsnaili.com.