Johnson Pump Water Pressure Regulator

The Johnson Pump Water Pressure Regulator (Model 40057) is an essential safeguard for any marine water system, protecting your onboard plumbing and fixtures from the destructive forces of pressure spikes. Whether you're running a cabin cruiser, sailboat, or center console, unregulated water pressure—especially from high-output pump systems—can crack fittings, rupture hoses, and damage sensitive appliances in minutes.

This compact regulator sits between your pump and distribution lines to maintain consistent, safe operating pressure throughout your freshwater or washdown system. Engineered by Johnson Pump, a trusted name in marine water systems for decades, this regulator uses internal diaphragm technology to automatically modulate flow and hold pressure at safe levels, typically in the 40–60 PSI range common to recreational vessels.

Boaters who rely on automatic or high-capacity water pumps—particularly those with large tanks or multiple heads and showers—will see immediate benefits in system longevity and reduced maintenance calls. The Johnson Pump Water Pressure Regulator installs in-line with standard hose fittings and requires no special tools for installation, making it ideal for tight engine compartments or galley installations where space is at a premium.