ACID RESISTANCE TESTS ACID-RESISTANCE TESTS CHEMICAL ANALYSIS AND TESTING CHEMICAL TESTS PIPES PIPEWORK SYSTEMS PIPING PLASTIC PIPES PLASTIC TUBES PLASTICS POLYVINYL CHLORIDE PRODUCTION CONTROL PRODUCTION PLANNING QUALITY CONTROL RESISTANCE SULPHURIC ACID TESTING TESTS UNPLASTICIZED POLYVINYL CHLORIDE CHEMICAL ANALYSIS AND TESTIN PIPES : TUBES PIPELINES