The pressure holding pilot (blue: PS 29-200) works inversely to the PR 29-100 and instead provides a constant pressure upstream of the valve. Placing the PR pilot in a by-pass pipe around the pump is a simple way of maintaining a constant pressure in a main line. Be sure not to connect the "by-pass" directly to the pump suction line. The pressure before the valve is equal to the set spring pressure. Pilots can only operate with flow in the piping system. Characteristics • 3-way control valve • Made of corrosion resistant materials • Minimizes pressure loss from the diaphragm valve by fully relieving the control chamber • Wide control range: by means of different springs corresponding to pressure levels • Accurate and easy to adjust
