Guangdong Endurance Electronic Equipment Co., LtdMain products: testing machine
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Hot and cold showers traced to the water servo valve? A six-station bench judges the Q-alpha curve by envelope in 45 seconds

Popularity:3Time of publication:2026/11/3 20:47:43

Model: NL-SFW-6

The problem

The constant-temperature comfort of a gas water heater depends on the water servo proportional valve: if the flow-frequency characteristic in the low-flow band drifts, winter showers alternate hot and cold and complaints land on the appliance maker. Before shipment every valve needs its flow-frequency characteristic measured point by point in both the low-flow and high-flow bands, with curves stored for traceability. Manual gauge readings cannot produce a complete curve, and with seven valve interface variants mixed on one line, changeover wiring wastes the takt.

Capability

Six stations arranged in two groups of three run independently without interference at 45-50 seconds per piece. Forty-two quick-change pneumatic fixtures match seven interface variants, with adjustable clamping stroke and separately replaceable connector tips. Six precision pressure-rated electronic flow meters cover 2-25 L/min (machine range 3-30 L/min) at 1 percent accuracy with 4 percent flow stability and 0.1 L display resolution. Frequency measurement spans 0-500Hz with 0.1Hz resolution and 0.5 percent full-scale accuracy, capturing up to ten flow points in one run and plotting the frequency-flow curve. Water pressure is held by a variable-frequency pump: 0-0.6MPa settable in multiple points (piping rated 0.75MPa), static and dynamic modes switchable, each pressure point with its own stability band, so the flow sweep pauses automatically if pressure drifts and resumes when it recovers. Driving the servo motor from maximum to minimum flow and back draws the complete Q-alpha dynamic curve, one set under static and one under dynamic pressure. The standard database stores up to five upper and lower envelope boundaries per model, connected from key points, and the curve inside the envelope passes automatically. Servo opening spans 20-6000 pulses with an adjustable DC 0-24V supply and a 24V 300mA constant-current source; one-inlet two-outlet circuits and connectors follow the valve interface. After each test compressed air blows out residual water at 90 percent or better drainage, with settable blow time and rust-free stainless water paths. A laser barcode scanner logs the serial number and recalls historical curves on repeat tests; the database holds 100000 records with full replay. Data interfaces follow factory IoT and MES requirements, with face-recognition check-in and 4G gateway upload available as options; faults raise an alarm and return the motor to zero.

NL test equipment

NL test equipment

Key specifications

  • Application: flow-frequency performance of water servo proportional valves
  • Stations: 6 (two groups of three), independent operation
  • Quick-change fixtures: 42 sets for 7 interface variants, adjustable stroke
  • Water pressure: 0-0.6MPa variable frequency constant pressure, piping rated 0.75MPa
  • Pressure hold: up to 1.75MPa at 1 percent accuracy, hold time settable
  • Flow range: 2-25 L/min (machine 3-30 L/min), accuracy 1 percent, stability 4 percent
  • Flow meters: 6 pressure-rated electronic meters, 0.75MPa, 0.1L display
  • Frequency: 0-500Hz, 0.1Hz resolution, 0.5 percent F.S accuracy
  • Curves: 0-10 flow points per run; Q-alpha dynamic curves for static and dynamic pressure
  • Envelope judgement: 1-5 upper and lower boundary sets per model in the standard library
  • Servo supply: DC 0-24V adjustable, 24V 300mA constant-current source, 20-6000 pulses
  • Water circuit: 100L tank, variable frequency supply, stainless steel paths

Applications

On-line full inspection and sampling of water servo proportional valves on gas water heater lines; outgoing inspection at constant-temperature valve cartridge and proportional valve plants; incoming flow-frequency verification by appliance makers; development and type testing in 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.

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