The definition of a modulating valve is an adjustable valve that can vary the flow rate through it depending on the situation. It is used in various fields, such as plumbing and HVAC. It works by using a mechanism to adjust the opening of the valve, allowing for the desired flow rate. This adjustment is done by using a remote switch or an automated device. The most common type of modulating valve is a ball valve, which works by using a ball to control the flow of the fluid. The ball is rotated by the remote switch or automated device to adjust the opening of the valve. The ball can be rotated to the desired position, allowing for the desired flow rate to be achieved. Modulating valves are used in a variety of applications, such as controlling the pressure of a gas or liquid, controlling the flow of air, and controlling the temperature of a liquid. They are also used in plumbing, HVAC, and other industrial applications. Modulating valves offer a quick