Outer Tub Passes Static Pressure Yet Weeps at the Weld in Year Two? NL-WOT-4 Washing Machine Tub Pressure-Cycling Fatigue Bench (washing machine test equipment)

The washing machine outer tub leaves the line with one check: fill, hold static pressure for a few minutes, no drip, release. The duty at home is not static. Every drain-pump start is a pressure pulse, the spin cycle throws a water film against the tub wall, and the suspension rods tug the tub mouth in a repeating pattern. A tub that holds static pressure can still weep at the weld after a year or two, crack at a suspension-rod mount, or seep at the shaft-seal bore toward the bearing. The user sees a puddle under the machine; service traces it to an out-of-warranty tub. The gap between a static pass and a cyclic life is where these complaints keep coming from.

What the NL-WOT-4 pressure-cycling bench measures

• Six stations with programmable cyclic pressure from 0 to 0.15 MPa, pulse frequency and ramp settable, reproducing the combined load of drain-pump pulses and spin-phase water loading (the structural branch of our washing machine test equipment range)
• Weld leak monitoring: per-station humidity and drip sensing during cycling, leak moment, position and cycle count logged automatically, life curves plotted against cycles
• Suspension-rod mounts and damper feet: off-centre loading reproduces spin imbalance, weld cracking and growth made visible
• Shaft-seal bore and bearing housing: coaxiality measurement combined with pressurised leak check, so micro-seepage after seal fitting is not missed
• Tub mouth seal face: laser measurement of deformation under cyclic pressure, seal compression change quantified
• Temperature alternation: 8 °C cold fill against 75 °C wash cycles, thermal stress at the welds stacking with seal shrinkage
• Detergent medium: solution mixed to real wash concentration, passivation layer and elastomer compatibility verified together
• Deformation mapping: radial and axial tub distortion swept against pressure, assembly interference surfaced early
• Barcode binding, leak cycles, positions and deformation exported per part for stamped and moulded lot comparison

Applicable standards

GB/T 4288 (household electric washing machines) with the structural and sealing clauses of GB 4706.1 and GB 4706.24, on the same basis as IEC 60335-2-7; cyclic pressure windows, cycle counts and leak criteria can follow the customer standard, sampling to GB/T 2828.

Stations and throughput

Six stations cycling overnight deliver tens of thousands of cycles, replacing “fill it and watch” with fatigue records of leak cycle counts, positions and deformation curves. Incoming tubs, assembly validation and after-sales seepage re-tests share one bench, moving a year-two complaint back onto the line where it shows up in hours.

Manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd. — a non-standard testing equipment manufacturer of washing-machine tub cycling benches, washing machine test equipment, dishwasher test equipment, pump test bench and pump performance test systems and level sensor life test machines.

Keywords: pump test bench, pump performance test, level sensor life test, dishwasher test equipment, washing machine test equipment.