Field adjustable gas valve and method of control

摘要

A valve unit includes a valve member that moves relative to a valve seat in response to a magnetic field generated by a coil. An input signal to the coil controls the extent of movement of the valve member relative to the valve seat, to control a gas flow rate therethrough. The gas valve unit also includes a setting adjustment device that provides a setting adjustment input utilized for calibrating or adjusting at least one gas flow rate. A valve controller is configured to receive an activation signal and to responsively send an input signal to the coil to move the valve member and establish at least one desired gas flow rate corresponding to the activation signal, wherein the valve controller is configured to adjust the input signal to the coil based on the setting adjustment input, to thereby enable field adjustment of at least one gas flow rate.

主权项

1. A gas valve unit for controlling a gas flow rate to a combustion apparatus, the gas valve unit comprising:
a valve member moveable relative to a valve seat, wherein an input signal to a coil controls the extent of movement of the valve member relative to the valve seat to control a gas flow rate through the gas valve unit to the combustion apparatus; a setting adjustment device that provides a setting adjustment input for calibrating at least one gas flow rate manufacturer-set in the gas valve unit; and a valve controller in communication with the setting adjustment device and the coil, the valve controller being configured to receive an activation signal prompted by a thermostat and to responsively send the input signal to the coil to move the valve member to establish at least one desired gas flow rate corresponding to the activation signal; the valve controller further configured to use a first value of the setting adjustment input from the setting adjustment device to calibrate a manufacturer-set high-capacity gas flow rate to obtain a calibrated high-capacity gas flow rate for a gas, and to use a second value of the setting adjustment input from the setting adjustment device to calibrate a manufacturer-set low-capacity gas flow rate to obtain a calibrated low-capacity gas flow rate for the gas, where in a single calibration, calibrating one of the high-capacity gas flow rate and the low-capacity gas flow rate is not effective to calibrate the other of the high-capacity gas flow rate and the low-capacity gas flow rate; the valve controller further configured to:
calibrate the manufacturer-set low- or high-capacity gas flow rate to adjust the corresponding low or high outlet pressure; andadjust the delimited range of outlet pressures in accordance with the adjusted low or high outlet pressure to obtain an adjusted range of outlet pressures having a rate of change different from a rate of change of the delimited range.