GB/T 23711.1-2019 "Test Methods for Pressure Vessels with Plastic Lining - Part 1: Spark Test" specifies the spark test method for the lining layer of pressure vessels with plastic lining, applicable to fluoroplastic lining products such as ETFE, FEP, PFA, PTFE, and PVDF. During the test, the detection voltage is set between 5 kV and 20 kV based on the lining thickness, and a probe is used to scan evenly along the lining surface. If defects such as pinholes or cracks are present, a breakdown alarm will be triggered. The test requires the use of a spark tester (which can be equipped with extension rods or rake-type probes to accommodate different container specifications). No specialized sample preparation is needed, as non-destructive testing is performed directly on the finished equipment. This method is a key means of evaluating the density of the lining layer.