FIELD OF THE INVENTION

The present invention relates generally to indicators adapted to be coupled to valves. More particularly, the present invention relates to indicators that provide a visual indication of whether a pressure relief valve has been activated.

BACKGROUND

Pressure relief valves are commonly used in many industries, such as the refrigeration industry. Pressure relief valves are used to control the amount of pressure within systems and containers, and flow through such systems and into and out of containers. For example, if pressure within a system or container increases too high, the pressure relief valve is activated and provides a mechanism for reducing the amount of pressure, thus protecting the system or container from pressure related failure. In general, pressure relief valves are replaced every five years, or sooner if the pressure relief valve is activated prior to the five years. However, it can be difficult and time consuming to identify whether a pressure relief valve has been activated, and thus should be replaced.

Solenoid-type valves are also commonly used in many industries as a type of pressure reduction valve. However, fluid pressure can build up in a system and may require a bleed off operation to be performed. It can be difficult to identify whether a bleed off operation should be performed to remove fluid (liquid or gas) from the system.

SUMMARY OF THE INVENTION

The present invention relates broadly to indicators adapted to provide a visual indication of whether a pressure relief valve has been activated due to an over pressure situation in a system. In an embodiment, the indicator (also referred to as a pop indicator), includes a main body, a piston disposed in the main body, and one or more O-rings disposed around the piston. Initially, the piston is in a first position, wherein the piston is retracted into the body, thus providing an indication that an over pressurization event has not occurred. However, when an over pressure situation occurs, the increased pressure causes the piston to move in a direction outwardly from the main body and against a friction force created by the O-ring. When the piston is moved—i.e., popped outwardly—an end of the piston extends outwardly of the body, thus providing a visual indication that an over-pressurization event has occurred. For example, the indicator may also be coupled to a pressure relief valve, and provide an indication that the pressure relief valve has been activated. In another example, the indicator may be coupled to a solenoid valve, and indicate that a system has experienced an overpressure situation, and fluid (liquid or gas) should be removed from the system to decrease the pressure.

An embodiment of the present invention broadly comprises an indicator adapted to be coupled to a valve, such as a pressure relief valve. The indicator includes a body having opposing first and second body ends, wherein the second body end is adapted to be coupled to the valve. A bore extends through the body between the first and second body ends. A piston having opposing first and second piston ends is disposed in the bore. The piston is movable between a retracted position, wherein the first piston end is disposed proximal to the first body end, and an extended position, wherein the first piston end is extended out of the body to provide a visual indication that an over-pressurization event, and thus activation of the pressure relief valve, has occurred.

Another embodiment of the present invention broadly comprises an indicator adapted to be disposed in a pressurized system. The indicator includes a body having opposing first and second body ends, wherein the second body end is adapted to be coupled to and be in either direct or indirect fluid communication with the system. A bore extends through the body between the first and second body ends. A piston having opposing first and second piston ends is disposed in the bore. The piston is movable between a retracted position, wherein the first piston end is disposed proximal to the first body end, and an extended position, wherein the first piston end is extended out of the body to provide a visual indication that pressure in the system has reached a threshold value.

