Model: NL-KFAQF-2
The problem
The safety valve is the fuse of a coffee machine water circuit: at brew pressure above ten bar, a valve that fails to relieve at the set point leaves the boiler heating under residual pressure, while one that opens too early drops the extraction pressure and cup taste drifts. The part is not a simple on-off device - three ports, three pressure zones and three pass combinations: 0-3bar air through A-C, 5-14bar water through A-B, above 15bar relief through A-C. Manual checking means reconnecting gauges three times per valve with judgement by eye, and the line cannot keep the takt.
Capability
This bench compresses the three zones into one takt. Ports A, B and C are clamped once by pneumatic quick couplings; zone one checks A-C continuity at 0-3bar of air, zone two checks A-B continuity at 5-14bar of water, zone three checks A-C relief opening above 15bar, each zone timed independently for 5-10s, with automatic pressure release after the test. The air side filters and regulates to 0-0.3MPa; the water side uses a 0-2.5MPa booster pump with an accumulator, accuracy 0.01MPa. Water filling, internal-leak and external-leak times are each settable 0-99.99s, and the 0-999999 cycle counter with power-off memory doubles as an open-reseat endurance test. Mechanically the bench uses ADK pneumatic components, Hiwin/TBI guides and quick-change aluminium fixtures matched to the 40x44x14mm valve sample. Two stations run independent PLCs so loading one never stops the other; takt is 35-50s per piece, about 150-200 pieces per hour on two stations.
Applicable standards
The assessment follows the structural safety clauses (pressure vessels and over-pressure protection) of Chapter 22 of GB 4706.1 General requirements for household and similar electrical appliances, with whole-machine safety under GB/T 4706.19-2024 for liquid heating appliances; the three pressure values, pass combinations, hold times and opening/reseating criteria follow the customer technical agreement and the valve drawing.
Key specifications
- Stations: 2, independent control
- Test piece: coffee machine safety valve, 40x44x14mm (per sample)
- Zone 1: 0-3bar air, A-C continuity, 5-10s adjustable
- Zone 2: 5-14bar water, A-B continuity, 5-10s adjustable
- Zone 3: above 15bar water, A-C relief opening, 5-10s adjustable
- Timing: water filling, internal leak, external leak each 0-99.99s
- Pressure accuracy: 0.01MPa
- Cycles: 0-999999, open-reseat endurance with power-off memory
- Air side: filtered and regulated to 0-0.3MPa
- Water side: booster pump 0-2.5MPa with accumulator and solenoid switching
- Pneumatics: ADK brand; guides Hiwin / TBI
- Fixture: quick-change aluminium with automatic post-test relief
- Frame: mobile, water-tested bench with drainage
- Control: independent PLC and touch screen per station; Schneider low-voltage electrics
Applications
Incoming inspection and line sampling of safety valves at coffee machine plants; 100 percent shipment inspection at safety valve suppliers; pre-testing for machine safety compliance and re-judgement of returned parts
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.