DIN EN 917:1997-03 Plastics piping systems - Thermoplastics valves - Test methods for resistance to internal pressure and leaktightness; German version EN 917:1997
1997DIN EN 917:1997-03 Plastics piping systems - Thermoplastics valves - Test methods for resistance to internal pressure and leaktightness; German version EN 917:1997
1997DIN EN 917:1997 Plastics piping systems - Thermoplastics valves - Test methods for resistance to internal pressure and leaktightness; German version EN 917:1997