The Fisher 627 Series is a line of direct-operated pressure reducing regulators designed for low and high-pressure systems, commonly used with natural gas, air, or a variety of other gases . They can be utilized in numerous applications, including as farm tap regulators, regulator-relief valves, monitoring regulators, slam-shut regulators, or high-pressure industrial regulators .

Maintenance is simplified by a two-bolt connection between the body and diaphragm casing, allowing trim parts to be replaced without removing the regulator body from the pipeline. The diaphragm case and/or regulator body can be rotated into any of four positions, providing installation flexibility in tight spaces. An adjusting screw locknut and protective cap are standard to discourage tampering with the pressure setting .

The 627R construction features an internal relief valve, which often eliminates the need for an external relief valve, reducing equipment and maintenance costs. This internal relief remains functional even if the disk or linkage fails. The series offers outlet pressure ranges from 5 to 500 psig in six different ranges. End connections include 3/4, 1, and 2-inch NPT, as well as NPS 1 or 2 with CL150, CL300, and CL600 RF flanged connections. Temperature capabilities range from -40° to 180°F .