Flow Control


1.  Rate of Flow Valve (106 / 206-RF)


2.5.1. Rate of Flow Valve (106 - 206-RF)The 106-RF and 206-RF rate of flow control valves are based on the 106-PG or 206-PG main valves.

The valve is ideal for limiting the flow to a pre-determined maximum (via maintaining a continuous pressure differential across an orifice). When the pressure differential is less than the set-point, the valve opens, allowing flow to meet predetermined demand. At the desired maximum set-point, the pilot reacts to small changes in sensing pressure and controls the main valve position by modulating the pressure above the diaphragm.

When the pressure drop across the orifice exceeds the set-point, the valve closes slightly, limiting the flow to the pre-set maximum. The orifice is usually sized to generate a pressure differential of 3 to 5 psi / 0.2 to 0.35 bar at the desired flow. Adjusting the pilot setting permits the maximum flow to be changed in the field above or below the original point.

  • Accurately limits flow to a pre-set maximum
  • Easily adjustable flow limit
  • Paddle-style orifice plate included
  • Optional orifice plate housing


2.  Excess Flow Valve (Burst Control Valve) 106 / 206-EF-8837BX


2.5.2. Excess Flow Valve (Burst Control Valve) 106 - 206-EF-8837BXThe 106-EF-8837BX and 206-EF-8837BX excess flow valves are based on the 106-PT and 206-PT Double Chamber main valves. The valve is designed to shut-off tightly when flow exceeds a predetermined amount.

The 625-RPD pilot senses the pressure drop of the valve and closes the valve when the tripping flow is reached. Typical pressure drop at tripping is 5 psi / 0.35 bar.

Tripping flow is adjusted by limiting the valve opening with the X102 Stroke Limiter. 10 psi / 0.7 bar inlet pressure must be maintained at the valve inlet when the valve has tripped to prevent self re-setting. This valve closes fast and from a significant velocity. If the upstream pipe is longer than 2,000 ft /600 m, closing speed control should be included. When tripped (closed), this valve has a continuous exhaust of about 1 GPM / 0.063 L/sec to drain.

  • Tight shut-off when flow exceeds a pre-determined amount
  • Manual re-activation required after failure
  • “Failure Signal” options available