Scope

This standard specifies the terms and definitions, requirements, test methods, inspection rules, marking, packaging, transportation and storage of polyester tubes for lead‑acid batteries.It applies to tubes for tubular plates of lead‑acid batteries.

Main Changes

• Chapters, sections and clauses have been rearranged according to content changes.

• Terms and definitions have been added.

• Appearance quality requirements for tubes have been revised.

• D.C. resistance measurement has been revised.

• Test method for deformation under force has been revised.

• Inspection classification has been revised.

Tubes

Technical Requirements

• Gas Tightness: Maintain sealing within the rated pressure range to prevent electrolyte leakage or back‑flow of external air.

• Corrosion Resistance: After immersion in sulfuric acid electrolyte, the mass loss rate, surface morphology change and mechanical strength degradation shall be within specified limits; no embrittlement or cracking shall occur during long‑term service.

• Dimensional Accuracy: Key dimensions such as bore diameter, spacing and channel length shall comply with GB/T series standards or the manufacturer's technical specifications.

• Mechanical Strength: Resist fracture under external impact, verified by drop‑weight impact test and bending fatigue test.

• Gas Discharge Efficiency: Ensure timely discharge of hydrogen, oxygen and other gases, while preventing acid mist emission and environmental pollution.

• Flame Resistance: Verify that the material flame‑retardant grade meets safety requirements by vertical burning test in accordance with UL94.

Test Methods

• Gas Tightness: Verified by helium mass spectrometry leak detection or pressure decay method.

• Corrosion Resistance: Evaluate corrosion resistance in sulfuric acid electrolyte by acid immersion test.

• Dimensional Accuracy: Precisely measure key dimensions of the tube using a coordinate measuring machine (CMM) or optical projector.

• Mechanical Strength: Conduct drop‑weight impact test and bending fatigue test.

• Gas Discharge Efficiency: Simulate battery charge–discharge cycles in a closed test chamber, and measure the exhaust flow rate, pressure threshold and gas diffusion uniformity of the tube.

• Flame Resistance: Conduct accelerated aging test on the tube in a high‑temperature environment (e.g. 70 °C–90 °C) to evaluate dimensional stability and performance retention; perform vertical burning test in accordance with UL94.