Pilotregulatorer

Pilotregulatorer, or pilot-operated regulators, are a class of pressure regulators that use a small pilot valve to control a larger main valve. The design enables high flow capacity and stable downstream pressure across varying supply conditions. The regulator maintains a set downstream pressure by adjusting the main valve opening in response to changes in demand and inlet pressure.

Operating principle: a spring sets the nominal pressure. Downstream pressure is sensed and used to position the pilot valve; the pilot creates a control pressure that acts on a diaphragm or piston connected to the main valve. If the downstream pressure rises above the setpoint, the pilot reduces the control pressure, causing the main valve to close slightly; when demand increases, the main valve opens more, allowing flow until the downstream pressure returns to the setpoint.

Two main configurations exist: direct-acting regulators (no separate pilot) and pilot-operated regulators (main valve controlled by a pilot). Pilot-operated regulators offer higher capacity and tighter control, suitable for large flows and fluctuating inlet pressures.

Key components include the main valve and seat, the pilot valve, an actuator (diaphragm or piston), springs for setpoint and return, a sensing/feedback line, and an adjustment mechanism.

Typical applications include natural gas distribution, compressed air systems, water and process industries, and chemical plants where stable downstream pressure is required despite variations in supply or flow demand.

Advantages include high flow capacity, improved regulation under fluctuating inlet pressure, and compact size for large capacities. Limitations include greater complexity, need for regular calibration, and potential pilot-line leakage if not properly maintained. Installation considerations include proper orientation, filtration to protect the pilot, and adherence to applicable standards for gas or liquid service.