Abstract: The valve consists of a closing device (7) pushed by a spring (8) to press the sealing face (9) against its seat (13). The closing device (7) can only be moved by action on the handle (18) provided the magnetic core (32) is attracted to the left, to enable the rod (35) to move the part (26) against the opposing action of a spring-loaded (39) bush (38). When the handle (18) is then operated, the rod (20) moves the part (26) downwards, which in turn presses down the rod (30) and allows the spring (8) to move the closing device (7) downwards. The part (26) is then locked by the engagement of its lip (42) beneath the end of a pin (40). If the excitation current is interrupted, the core (32) and the part (26) return to their original position, which releases the moving part (26) and the rod (30).The spring (31) then returns the closing device (7) to the position illustrated.