When the level lowers, the floating valve opens to supply water; there is pressure inside the water in the pipe to hold the piston inside the valve up, then the sealing-face opens and the valve supplies water. When the level gets to the controlled line, the floating valve closes and the piston moves downwards to closes the sealing-face, at last the vale stops the water supply.

DN	40	50	65	80	100	125	150	200	250	300	350
D	145	160	180	195	215	245	280	335	405	460	520
D1	110	125	145	160	180	210	240	295	355	410	470
L	107	115	125	135	146	165	180	215	255	285	325
H	235	243	258	280	307	358	400	490	576	663	750