Anti-syphon fluid control valve apparatus and method

An anti-syphon valve for fluid transfer comprising:

• an elongate inlet channel having first and second ends;
• an elongate outlet channel, disposed alongside the inlet channel, having first and second ends;
• a rotatable valve seat means laterally-disposed in the inlet and outlet channels between their ends, thereby dividing the inlet channel into a first section between its first end and the valve seat means and a second section between its second end and the valve seat means, and dividing the outlet channel into a first section between its second end and the valve seat means and a second section between its first end and the valve seat means, the valve seat means being rotatable about an axis substantially parallel to the inlet and outlet channels for selectively closing and opening the inlet channel while leaving the outlet channel at least partially open in all rotational positions;
• a float disposed near the second end of the inlet channel, adapted to cover the second end of the inlet channel when fluid pressure in the second section of the outlet channel exceeds or substantially equals fluid pressure in the second section of the inlet channel and uncover the second end of the inlet channel when fluid pressure in the second section of the inlet channel exceeds or substantially equals fluid pressure in the second section of the outlet channel.

An anti-syphon fluid valve comprising:

• an elongate inlet pipe leg with upper and lower ends;
• an elongate outlet pipe leg with upper and lower ends;
• wherein the inlet and outlet legs are joined together at their upper ends, forming a base pipe with their combination, each leg being approximately in the shape of a semi-circle and in volume substantially half of the base pipe;
• a separating wall between the inlet and outlet legs in the base pipe;
• a lower seat overlying the upper ends of the inlet and outlet legs, the lower seat comprising a semi-circular outlet opening overlying the upper end of the outlet leg and a quarter-circular inlet opening overlying the upper end of the inlet leg, with the rest of the upper end of the inlet leg being covered by a quarter-circular solid section of the lower seat;
• an upper seat overlying the lower seat, the upper seat being rotatable about a common axis extending through the approximate centers of the upper and lower seats, the upper seat comprising a circular section divided into oppositely oriented solid quarter-circular blocks and oppositely oriented quarter-circular openings and having a slot extending along its periphery;
• a peg extending through the slot in the upper seat and movably engaging the lower seat;
• an elongate valve stem post having an upper and lower end, the upper seat being affixed at the lower end, extending substantially parallel to the base pipe;
• an elongate inlet passage disposed within the valve stem post and having upper and lower ends, the lower end being situated over the inlet opening of the lower seat and the upper end being disposed in the approximate cross-sectional center of the valve stem post;
• an elongate outlet passage disposed within the valve stem post and having upper and lower ends, the lower end being situated over the outlet opening of the lower seat and the upper end being annular and disposed concentrically with the upper end of the inlet passage;
• a float disposed in the valve stem post above the upper end of the inlet passage and adapted to descend by force of gravity over the upper end and seal it in the absence of countervailing forces;
• a plurality of ribs extending laterally from the float to the valve stem post;
• a float block disposed over the float and secured within the valve stem post such that the float presses against the float block when forced from its position on the upper end of the inlet passage;
• a vent hole disposed in the float block within the area of contact of the float against the float block;
• a substantially cup-shaped handle disposed over the upper end of the valve stem post, the handle comprising vent passages in fluid communication with the vent hole in the float block, and being adapted for lengthwise movement along the valve stem post;
• a plurality of first splines arranged substantially annularly around the valve stem post and protruding outwardly therefrom toward the handle;
• a plurality of second splines arranged substantially annularly around the handle and protruding inwardly therefrom toward the valve stem post, being adapted selectively to engage the first splines such that a user can rotate the valve stem post through the handle.