DIN EN 14451 E:2019 防止飲用水回流污染的裝置 在線防真空閥 DN 10 至 DN 50(含) D 系列 A 型 草案
Draft Document - Devices to prevent pollution by backflow of potable water - In-line anti-vacuum valves DN 10 to DN 50 inclusive - Family D, type A; German and English version prEN 14451:2019