An apparatus (10, 110, 1000, 2000, 3000, 4000) for a urinal (20, 1020), comprising: a plate member (32, 1040, 4040) adapted to form a seal with a urinal outlet (38, 1060), the plate member (32, 1040, 4040) defining a throughbore (16, 1080) permitting the passage of liquid, in use, from the urinal (20, 1020) to a soil pipe (24, 1100, 3100); a diaphragm (26, 1160, 2160, 3160) removably located in the plate member throughbore (16, 1080), the diaphragm (26, 1160, 2160, 3160) adapted to permit the passage of liquid through the throughbore (16, 1080) in one direction only from the urinal (20, 1020) to the soil pipe (24, 1100, 3100), and the diaphragm (26, 1160, 2160, 3160) is adapted to be removed through the plate member throughbore (16, 1080); and a collar (48, 1200) releasably located within the throughbore (16, 1080) and adapted to prevent axial movement of the diaphragm (26, 1160, 2160, 3160) with respect to the throughbore (16, 1080); wherein the diaphragm (26, 1160, 2160, 3160) comprises a polymeric duckbill shaped valve having a first flexible wall and a second flexible wall, the first and second flexible walls being arranged to define a diaphragm throughbore, the first and second flexible walls being arranged to normally lie in a diaphragm throughbore closed position in which the diaphragm throughbore is sealed; wherein the diaphragm (26, 1160, 2160, 3160) comprises a flange (46, 1220), the flange (46, 1220) extending radially outwards from a diaphragm inlet, the diaphragm inlet being held open by the diaphragm flange (46, 1220) connected to an upper portion of the first and second flexible walls; the apparatus, (10, 110, 1000, 2000, 3000, 4000) further comprising a filter and/or deodorising unit (12, 112, 1180); and wherein the diaphragm (26, 1160, 2160, 3160) is adapted to be removed, in use, upwardly through the plate member throughbore (16, 1080). a plate member (32, 1040, 4040) adapted to form a seal with a urinal outlet (38, 1060), the plate member (32, 1040, 4040) defining a throughbore (16, 1080) permitting the passage of liquid, in use, from the urinal (20, 1020) to a soil pipe (24, 1100, 3100); a diaphragm (26, 1160, 2160, 3160) removably located in the plate member throughbore (16, 1080), the diaphragm (26, 1160, 2160, 3160) adapted to permit the passage of liquid through the throughbore (16, 1080) in one direction only from the urinal (20, 1020) to the soil pipe (24, 1100, 3100), and the diaphragm (26, 1160, 2160, 3160) is adapted to be removed through the plate member throughbore (16, 1080); and a collar (48, 1200) releasably located within the throughbore (16, 1080) and adapted to prevent axial movement of the diaphragm (26, 1160, 2160, 3160) with respect to the throughbore (16, 1080); wherein the diaphragm (26, 1160, 2160, 3160) comprises a polymeric duckbill shaped valve having a first flexible wall and a second flexible wall, the first and second flexible walls being arranged to define a diaphragm throughbore, the first and second flexible walls being arranged to normally lie in a diaphragm throughbore closed position in which the diaphragm throughbore is sealed; wherein the diaphragm (26, 1160, 2160, 3160) comprises a flange (46, 1220), the flange (46, 1220) extending radially outwards from a diaphragm inlet, the diaphragm inlet being held open by the diaphragm flange (46, 1220) connected to an upper portion of the first and second flexible walls; the apparatus, (10, 110, 1000, 2000, 3000, 4000) further comprising a filter and/or deodorising unit (12, 112, 1180); and wherein the diaphragm (26, 1160, 2160, 3160) is adapted to be removed, in use, upwardly through the plate member throughbore (16, 1080).