LST EN 12050-4-2002 Wastewater lifting plants for buildings and sites - Principles of construction and testing - Part 4: Non-return valves for faecal-free wastewater and wastewater containing faecal matter
2015LST EN 12050-4-2015 Wastewater lifting plants for buildings and sites - Part 4: Non-return valves for faecal-free wastewater and wastewater containing faecal matter
2002LST EN 12050-4-2002 Wastewater lifting plants for buildings and sites - Principles of construction and testing - Part 4: Non-return valves for faecal-free wastewater and wastewater containing faecal matter