In selecting a regulator there are two basic operating characteristics to be considered. These characteristics are Regulation and Flow.
The regulation characteristic indicates the ability of the regulator to maintain a relatively constant delivery pressure as the supply pressure changes due to the cycling of the compressor or to upstream pressure changes caused by other equipment.
Flow characteristic indicates the ability of the regulator to maintain a relatively constant delivery pressure as the downstream flow demand changes. This can occur when downstream air tools or other devices are being turned on and off.
Choosing a regulator requires knowing what type of features are needed in addition to the correct regulation and flow characteristics. These features could be flow capacity, pressure and temperature rating, fluid compatibility, relieving or nonrelieving, pilot operated, balanced valve, diaphragm or piston sensor, high relief flow, full flow gauge ports, ease of adjustment, locking and tamper proofing capability and mounting.
Pilot Operated
These regulators use air pressure instead of a spring to create force for operation. This type of regulator is often mounted in overhead lines with another regulator mounted in a more convenient place controlling it.
Balanced Valve
A regulator with a balanced valve design will have good regulation characteristics. A balanced valve design has equal pressure above and below the valve. These pressures cancel out the force acting in each direction on the valve; therefore, the valve is balanced. This feature reduces the effect of varying primary pressure on the secondary pressure.
Diaphragm or Piston Pressure Sensors
Most regulators use a diaphragm as the pressure sensor. Diaphragms are sensitive and do not have seal friction to overcome before responding to pressure changes. Piston sensors do not respond to changes in pressure as readily as diaphragm sensors because of seal friction.
High Relief Flow
Some applications require a high relief flow such as when deflating tires during manufacturers’ testing. The “Microtrol” regulator, among others, has a high relief flow capability.
Full Flow Gauge Ports
These ports are full open to the secondary pressure and can be used as an additional outlet for 1/4" piping.
Ease of Adjustment
Some regulators have a very large diaphragm area which requires high adjusting spring forces to move. Regulators with smaller sensing areas require lower adjusting spring forces to move and are much easier to adjust such as the NORGREN Designer series.
Tamper Resistant Pressure Setting & Factory Preset, Nonadjustable Pressure Settings
The pressure setting on regulators with a knob adjustment can be made temper resistant in the field by the addition of seal wire, a feature not available with some competitors’ regulators. In addition, some regulators can be set at the factory at a specified pressure setting. These regulators are not field adjustable, as the adjusting screw is pinned or otherwise locked in place.
Mounting
Not all manufacturers offer both bracket and panel mounting. Look for these features to give a choice of the best mounting style.
