Hydraulic regulators maintain the output pressure of a hydraulic system at a set value, minimizing fluctuations in a pressurized line. A hydraulic regulator is typically made of steel, coated steel, or stainless steel and comes with a variety of connections. Hydraulic regulators are designed to hold a tight seal even as the pressure in the line rises. Hydraulic regulators may be used in land-based applications or may be specially designed to work underwater.