Abstract: An anti-syphon valve comprises a base pipe having inlet and outlet legs and a valve seat, disposed at the top of the base pipe within a valve stem post, which can be rotated selectively to block the inlet leg (closed position) or open it (open position). A metering peg extends from the valve stem post into a receptacle in the valve seat. Inlet and outlet passages corresponding to the inlet and outlet legs are disposed above the seat, and a float located at the top of the inlet passage allows fluid flow from the inlet passage into the outlet passage in the open position while blocking fluid flow from the outlet passage to the inlet passage in the closed position. Vent passages are provided above the float to enable communication of the outlet passage to atmosphere in the closed position. A handle is provided on the valve stem post to selectively rotate the latter to place the valve in open or closed position.

Abstract: An anti-syphon valve comprises a base pipe having inlet and outlet legs and a valve seat, disposed at the top of the base pipe within a valve stem post, which can be rotated selectively to block the inlet leg (closed position) or open it (open position). A metering peg extends from the valve stem post into a receptacle in the valve seat. Inlet and outlet passages corresponding to the inlet and outlet legs are disposed above the seat, and a float located at the top of the inlet passage allows fluid flow from the inlet passage into the outlet passage in the open position while blocking fluid flow from the outlet passage to the inlet passage in the closed position. Vent passages are provided above the float to enable communication of the outlet passage to atmosphere in the closed position. A handle is provided on the valve stem post to selectively rotate the latter to place the valve in open or closed position.

Abstract: An anti-syphon valve comprises a base pipe having inlet and outlet legs and a valve seat, disposed at the top of the base pipe within a valve stem post, which can be rotated selectively to block the inlet leg (closed position) or open it (open position). A metering peg extends from the valve stem post into a receptacle in the valve seat. Inlet and outlet passages corresponding to the inlet and outlet legs are disposed above the seat, and a float located at the top of the inlet passage allows fluid flow from the inlet passage into the outlet passage in the open position while blocking fluid flow from the outlet passage to the inlet passage in the closed position. Vent passages are provided above the float to enable communication of the outlet passage to atmosphere in the closed position. A handle is provided on the valve stem post to selectively rotate the latter to place the valve in open or closed position.