The poppet of a pressure regulator is closed by which of the following?

The poppet of a pressure regulator is closed by downstream pressure. In a pressure regulator, the poppet is a critical component that helps maintain the desired outlet pressure. When the downstream pressure reaches the set point determined by the regulator, it exerts a force on the poppet, pushing it to a closed position.

This mechanism allows the regulator to control the flow and pressure of the fluid passing through it by responding to the pressure levels downstream. If the downstream pressure drops below the set point, the poppet opens to allow more flow in until the pressure is re-established. Thus, downstream pressure is essential for determining when the poppet should close to maintain the desired system pressure.

In contrast, upstream pressure acts differently; it influences the overall regulation process but does not close the poppet. Similarly, the adjustment spring and poppet spring serve different roles, providing force and balance but are not the direct influence that closes the poppet. Understanding this relationship is crucial for working with pressure regulators in pneumatic systems.