The PCFCD-1N1 is designed to maintain a constant flow rate, which the customer can adjust, regardless of upstream or downstream pressure variations. It works with both liquids (incompressible fluids) and gases (compressible fluids) but is primarily intended for the control of liquids. The pressure regulation is accomplished with a low friction diaphragm mechanism. It controls flow rates of 0 to 4.2 gallons per hour of water (0 to 20 cubic feet/hour of Air). It is especially suited for the control of low flow rates. The maximum rated inlet supply pressure is 500 psig. Both the inlet and outlet ports are tapped 10-32. The valve body is both small and lightweight allowing for convenient in-line mounting without the need for a panel mount thread.