Regulator flow measurement apparatus

A method of calibrating a pressure regulator disposed in a fluid flow passage, the pressure regulator having a throttling element moveable in the flow passage, and a temporary flow meter disposed downstream of the throttling element, the method comprising the steps of:

• generating an upstream pressure value P1 by measuring fluid pressure upstream of the throttling element;
• generating a downstream pressure value P2 by measuring fluid pressure downstream of the throttling element;
• generating a travel value Y by determining a position of the throttling element;
• calculating a calculated fluid flow value Fc based on the upstream pressure value P1, downstream pressure value P2, and travel value Y;
• reading a measured fluid flow value Fm from the flow meter;
• and
• generating a stem position coefficient correction based on the travel value Y, the calculated fluid flow value Fc, and the measured fluid flow value Fm.

Apparatus for calibrating a pressure regulator disposed in a fluid flow passage, the pressure regulator having a throttling element moveable in the flow passage, the apparatus comprising:

• a first pressure sensor in fluid communication upstream of the throttling element for measuring an upstream pressure;
• a second pressure sensor in fluid communication downstream of the throttling element for measuring a downstream pressure;
• a travel sensor for determining a throttling element position;
• a flow meter disposed downstream of the throttling element for reading a measured fluid flow value;
• a processor associated with the first pressure sensor, second pressure sensor, travel sensor, and flow meter, the processor having a stored program for determining a stem position coefficient correction based on the upstream pressure, the downstream pressure, the throttling element position, and the measured fluid flow value;
• wherein the stem position coefficient correction includes a calculation of a plurality of stem position coefficient correction factors for a plurality of throttling element positions.

Apparatus for calibrating a pressure regulator disposed in a fluid flow passage, the pressure regulator having a throttling element moveable in the flow passage, the apparatus comprising:

• a first pressure sensor in fluid communication upstream of the throttling element for measuring an upstream pressure;
• a second pressure sensor in fluid communication downstream of the throttling element for measuring a downstream pressure;
• a travel sensor for determining a throttling element position;
• a flow meter temporarily installed downstream of the throttling element for reading a measured fluid flow value;
• a processor associated with the first pressure sensor, second pressure sensor, travel sensor, and flow meter, the processor having a stored program for determining a stem position coefficient correction based on the upstream pressure, the downstream pressure, the throttling element position, and the measured fluid flow value.