The purpose of a refrigeration valve is to regulate the flow of refrigerant in a cooling system. This is achieved through a series of mechanisms. First, the refrigerant expands within the valve. This causes the pressure inside to rise and travel through the capillary tube and chamber above the diaphragm. As the refrigerant expands, it pushes the diaphragm down, and the pin, which controls the flow of refrigerant through the orifice assembly, moves downward. When the pin pushes down on the stop, the valve opens, increasing the flow of refrigerant to the outlet and causing superheat.

A refrigeration valve has many important functions and parts. Each piece of equipment functions to achieve the desired efficiency. The main body houses the functional parts of the valve. The orifice controls the flow of liquid refrigerant. The diaphragm exerts pressure on the operational pin. This prevents the refrigerant from overflowing the system. The diaphragm is the most important component of a refrigeration valve. Despite its name, it contains many different parts.

A multi-position valve is a common confusion for residential technicians. A multi-position valve allows full flow through the valve body while closing its access port. In a conventional refrigeration system, this valve does not have a Schrader port. However, the multi-position valve's ribbed coil design prevents back pressure from building up on the port. This makes it necessary to understand the function of the valve before installing it in a system.

Thermostatic expansion valve (TEV) regulates the flow of liquid refrigerant based on the cooling load of the system. This type of valve is typically found on larger capacity systems. When the evaporator warms, the TEV provides a higher flow rate and decreases the flow rate when the system cools. These three forces work together to maintain a constant flow of refrigerant according to the load.

A three-way valve includes an intermediate member, a first and second axial end bell, and a minor outlet connected to the suction side of a refrigerant compressor. The removably-removable cartridge includes all movable and stationary parts of a three-way valve. The axially extending cavity is sealed by a gasket member. The three-way valve has a lateral opening defined by the shaft.

Another type of valve is the magnetic check valve, which controls the direction of refrigerant flow. This type of valve is primarily used in large and medium-sized refrigeration units. This type is characterized by low differential pressure and has two floats. The low-side float is used to control the flow of liquid refrigerant, while the high-side float controls the flow of gaseous refrigerant. This type of valve also allows for reversal of flow.