Static Pressure Held at the Factory, Seam Weeping Two Years Later? NL-DPF-4 Dishwasher Tank Seam Pressure Fatigue Bench (dishwasher test equipment)

A dishwasher tank is a drawn stainless body joined to welded flanges. Factory acceptance is usually one cold static hold: pressure steady, unit passed. The duty in a kitchen is anything but static — fill surge, heat-up pressure rise, drain collapse, several cycles a day, thousands a year, with 60 to 70 °C water soaking the seams throughout. Residual stress and intergranular attack at the weld heat-affected zone work together, and the flange sealing face slowly loses preload. By the time the weep is noticed, the cabinet base and the floor are already wet. A static tightness test finds the unit that leaks now; it cannot find the unit that leaks after thirty thousand cycles. Those are two different questions, and they need two different benches.

What the NL-DPF-4 seam and flange pressure fatigue bench measures

• Four stations, cyclic pressure: 0.02 to 1.2 MPa square and trapezoidal profiles, ramp rate and hold time set independently, tens of thousands of cycles per sample (the structural strength branch of our dishwasher test equipment range, complementing the cold static tightness bench)
• Zone-based leak localization: sensing points on seams, flanges and port bosses, pressure-decay and humidity channels judged together, the leak placed in a zone rather than by eye
• Hot water duty: loop tank controlled from 20 to 85 °C, thermal cycling and cold-hot alternation run as separate programs, heat-affected zones exposed first
• Pressure waveform record: peak, trough and ramp slope archived for every cycle, anomalous waveforms flagged automatically
• Strain and deformation: gauges near critical seams, stress amplitude and plastic accumulation visible through the campaign
• Door seal in step: door cycling alternated with tank pressure cycles, seal face following under dynamic duty checked as well
• Post-cycle verification: back to cold static hold at the target cycle count, leak rate and deformation logged per unit
• Barcode and batch binding, cycle count, leak zone and strain peaks exported per unit for sheet and welding process lot comparison

Applicable standards

GB 4706.1 (household appliances – general safety), GB 4706.25 (dishwashers – particular requirements), IEC 60335-2-5, GB/T 20290 (methods for measuring the performance of household dishwashers) and the relevant clauses of IEC 60436; pressure band, cycle count and leak criteria can follow the customer standard and tank specification, sampling to GB/T 2828.

Stations and throughput

Four stations running continuously extend “one static hold” into a full record of pressure waveforms, leak zones, strain history and post-cycle verification. Incoming tanks, welding process validation and end-of-line sampling share one bench, keeping the seam weep that shows up a year or two later out of the field.

Manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd. — a non-standard testing equipment manufacturer of dishwasher tank seam pressure fatigue benches, dishwasher test equipment, washing machine 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.