Abstract: A self-contained control device for a system having a first source provided with a changeable fluid pressure value and a second source provided with a changeable vacuum value and having a pressure operated control unit that changes its operating condition in relation to the value of the pressure signal directed thereto, the control device having pneumatically operated control means adapted to be operatively interconnected to the sources and the control unit for increasing the pressure signal from the first source to the unit as the pressure value from the first source increases from a first value thereof to a second value thereof and for thereafter decreasing the pressure signal from the first source to the unit as the pressure value from the first source further increases from the second value thereof to a third value thereof. The control means are adapted to produce the signal in substantially the same manner but at different values for different levels of vacuum at the second source.

Abstract: A pneumatic indicator device having a housing carrying a movable flag that in one position thereof visually indicates one pneumatic condition of the device and in another position thereof visually indicates another pneumatic condition of the device, the housing also carrying an electrical switch which is operatively associated with the movable flag so that the switch electrically indicates the positions of the flag for remote indication purposes.

Abstract: A fluid mixing valve construction having a housing provided with a pair of inlets respectively interconnected by a pair of valve seats to an outlet and with a valve member operated by a condition responsive unit for controlling the valve seats in accordance with the condition of fluid passing to the outlet and sensed by the condition responsive unit. A second condition responsive unit is operatively interconnected to the valve member to close one of the valve seats with the valve member if the first mentioned condition responsive unit does not close the one valve seat with the valve member even though the same is sensing a condition that would require the first mentioned condition responsive unit to close the one valve seat whereby the fluid mixing valve construction is substantially fail-safe.

Abstract: An indicator construction having a housing carrying a movable flag member and a movable plunger operatively associated with the flag member to cause movement thereof upon movement of the plunger, a spring member being operatively interconnected to the plunger and operatively interconnected to the movable flag member to cause movement thereof upon movement of the plunger.

Abstract: A pneumatic indicator device having a housing carrying a movable flag that in one position thereof visually indicates one pneumatic condition of the device and in another position thereof visually indicates another pneumatic condition of the device, the housing also carrying an electrical switch which is operatively associated with the movable flag so that the switch electrically indicates the positions of the flag for remote indication purposes.

Abstract: A fluid mixing valve construction having a housing provided with a pair of inlets respectively interconnected by a pair of valve seats to an outlet with a valve member operated by a condition responsive unit for controlling the valve seats in accordance with the condition of fluid passing to the outlet and sensed by the condition responsive unit. A second condition responsive unit is operatively interconnected to the valve member to close one of the valve seats with the valve member if the first mentioned condition responsive unit does not close the one valve seat with the valve member even though the same is sensing a condition that would require the first mentioned condition responsive unit to close the one valve seat whereby the fluid mixing valve construction is substantially fail-safe.

Abstract: A valve construction having a housing provided with an inlet and an outlet and a movable valve seat disposed between the inlet and the outlet. A movable valve member is provided for opening and closing the valve seat. A condition responsive unit is operatively associated with the valve member to move the valve member relative to the valve seat in response to the conditions sensed by the condition responsive unit. A snap opening unit is interconnected to the valve seat to rapidly move the valve seat away from the valve member when the valve member has initially opened the valve seat a certain amount.