What effect does tightening down the adjustment screw on a pressure reducing valve have on the pressure?

Tightening down the adjustment screw on a pressure reducing valve increases the pressure downstream of the valve. This is because the adjustment screw adjusts the spring tension on the valve's diaphragm. When the screw is tightened, it compresses the spring more, allowing the valve to maintain a higher pressure against the flow of steam or gas.

As the flow encounters resistance, a greater force is needed to open the valve, resulting in a higher outlet pressure. This design is fundamental in controlling the pressure in steam systems, ensuring that the pressure remains within safe and optimal levels for effective operation. Understanding how this mechanism works is critical for maintenance and adjustment of pressure reducing valves in commercial food equipment systems.