American Meter- Industrial Gas Pressure Regulator 1803Product Description Available with 1 1 2" NPT and 2" NPT connections. The 1803 is capable of handling inlet pressures up to 125 PSI and can offer outlet pressures ranging from 3. 5" W. C. to 5 PSI. The maximum flow capacity in higher pressure situations is 20,000 SCFH depending on orfice size and inlet pressure. Note: The 1800 Series can be special ordered with Full Relief, Partial Relief or No Relief Regulator. Over pressure shut off models are also