Abstract: A valve includes a plunger which is movable by actuating means such as a solenoid coil, air pressure or other means to move a valve member toward and away from a valve seat. The fluid flow area of the valve is sealed from the actuating means by the diaphragm, O-rings or other forms of sealing structure. In order to insure against leakage past the diaphragm or seal and especially against leakage into the actuating means, the construction includes another diaphragm or seal spaced from the first seal providing a seal space between the first and second diaphragms or seals. In the event of leakage past the first sealing means, flow of the liquid into the space between the first and second sealing means causes an outward flow of the fluid through a detecting passage which thereby provides means which disclose the leakage past the first sealing means so that the first sealing means can be immediately replaced before any damage to the actuating means or to the system itself.

Abstract: This invention relates to a valve mechanism of a variety of uses. In one use the valve positively seals a line through which fluid flows against reverse or backflow of the fluids in any position in which the valve is disposed. In another use the valve mechanism functions as a vacuum breaker. In still another use it functions as a foot valve. The same valve structure is utilized in all of the aforesaid functions. Generally, the valve structure has a housing comprising an inlet member and an outlet member which are joined together. A flexible diaphragm is secured between the inlet and outlet members. One end of the inlet member is provided with a shoulder or flange adjacent the flexible diaphragm. One end of the outlet member is provided with a valve support seat adjacent the flexible diaphragm. The flexible diaphragm has apertures or orifices interiorly of its perimeter and a solid central portion.

Abstract: A valve includes a plunger which is movable by actuating means such as a solenoid coil, air pressure or other means to move a valve member toward and away from a valve seat. The fluid flow area of the valve is sealed from the actuating means by the diaphragm, O-rings or other forms of sealing structure. In order to insure against leakage past the diaphragm or seal and especially against leakage into the actuating means, the construction includes another diaphragm or seal spaced from the first seal providing a seal space between the first and second diaphragms or seals. In the event of leakage past the first sealing means, flow of the liquid into the space between the first and second sealing means causes an outward flow of the fluid through a detecting passage which thereby provides means which disclose the leakage past the first sealing means so that the first sealing means can be immediately replaced before any damage to the actuating means or to the system itself.

Abstract: A valve includes a plunger which is movable by actuating means such as a solenoid coil, air pressure or other means to move a valve member toward and away from a valve seat. The fluid flow area of the valve is sealed from the actuating means by the diaphragm, O-rings or other forms of sealing structure. In order to insure against leakage past the diaphragm or seal and especially against leakage into the actuating means, the construction includes another diaphragm or seal spaced from the first seal providing a seal space between the first and second diaphragms or seals. In the event of leakage past the first sealing means, flow of the liquid into the space between the first and second sealing means causes an outward flow of the fluid through a detecting passage which thereby provides means which disclose the leakage past the first sealing means so that the first sealing means can be immediately replaced before any damage to the actuating means or to the system itself.