1. Scope

1.1 These provisions apply to the construction, materials, performance, and testing of NPS 1-1/4 in and smaller self-acting service-type regulators with internal relief valves or overpressure cut-off (OPCO)* devices, or both, utilized to control the pressure of gas delivered to a customer;s piping at a delivery pressure of 5 to 9 in water column (1.24 to 2.24 kPa), for installations designed for capacities up to 250 SCFH (7.1 m3/h). *Overpressure cut-off (OPCO) devices are also referred to as overpressure shut-off (OPSO) devices.

1.2 The yard-pound units provided are the standard. The SI (metric) equivalents in parentheses may be approximate values and are provided for information only, or for markings where both units of measurement are required.