Model: NL-STF-1

The problem

The four-way valve is the master switch of heat-pump heating and cooling: when the worst batch fails to reverse in winter or summer the whole lot is written off. The five checks - maximum and minimum operating pressure differential, internal leakage, mid flow and endurance - done by hand on ad-hoc rigs rigs measure only a few valves a day; with a dozen port sizes from 1P to 20P mixed in, fixture changeover is chaos and nobody can watch the pressure drift of a life test all night.

Capability

One performance station plus two endurance stations run at the same time. The performance station runs the five checks in one automatic sequence: minimum operating differential reversal, maximum operating differential reversal, internal leakage and mid flow. The two life stations run reversing endurance with or without a 1.5L surge tank, with automatic oil refill at a controllable 30mL per hour. Ranges follow the assessment points: maximum differential 0-5MPa (covering the 2.3-3.1MPa reversal test), minimum differential 0-0.6MPa with the 0.23-0.34MPa criterion, internal leakage air 0-2.5MPa, sample maximum 3.5MPa. Digital gauges 0-6MPa x2 and 0-1.6MPa x1 within 0.5 percent; electronic flow meter to 20000 cubic cm per minute at 2 percent, mid flow 0-200L/min. The coil supply is 0-300V continuously variable with a built-in 50/60Hz inverter and supports the minimum operating voltage check (reversal below 85 percent of rated voltage). Reversal time 1-12s settable; timed air-tightness 0-6MPa for 0-5min with automatic relief. Every line is monitored, over-pressure stops the test with the count recorded; test time and cycles are recallable and survive power loss. Fixtures cover five sizes from 1P to 20P, extruded aluminium and Q235A with O-ring seals, expandable to samples. A 15-inch industrial PC with Mitsubishi FX3U and 4AD module runs manual and automatic modes; outline 1600x900x1750mm, 220V, about 2kW.

Key specifications

• Application: comprehensive performance of four-way reversing valves
• Stations: 1 performance + 2 endurance, running together
• Tests: internal leakage, max/min operating differential, mid flow, endurance
• Max differential: 0-5MPa settable (reversal test 2.3-3.1MPa)
• Min differential: 0-0.6MPa settable, criterion 0.23-0.34MPa
• Internal leakage air: 0-2.5MPa settable; sample max 3.5MPa
• Pressure display: 0-6MPa digital x2, 0-1.6MPa x1, better than 0.5 percent
• Flow: to 20000 cubic cm/min, 2 percent; mid flow 0-200L/min
• Coil supply: 0-300V variable, built-in 50/60Hz inverter; 85 percent rated voltage reversal check
• Reversal time: 1-12s settable
• Air-tightness: 0-6MPa timed 0-5min, automatic relief
• Life modes: with or without 1.5L surge tank, oil refill 30mL/h controllable

Applications

Outgoing and type testing at four-way valve plants; incoming reversal verification by heat pump and AC makers; differential and endurance development in valve laboratories; commissioned testing at refrigeration parts institutions

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.