NOT KNOWN DETAILS ABOUT HIGH PRESSURE NATURAL GAS REGULATORS

Self-Operated Regulators. High-Pressure Gas Regulators Concern; have to know how or what size of regulator I will require to cut pressure down from 21psi in to about 3psi to operate a 120 btu boiler?The Masoneilan 172 sequence are spring loaded direct-operated, pressure cutting down regulators. Their main operate is to control the outlet pressure.