The H91 Series valves are two-wire, electrically operated shutoff valves that automatically open and close on a demand signal from a thermostat or other controlling device. They are suitable for both natural and LP gas and can be used for gas-fired appliances with a maximum operating pressure of 0.5 psi. Several voltage and cover options are available and sizes range from 1/8" NPT to 1" NPT including some compression fitting options.