BS 4161-4 70th Edition, March 31, 1970
Gas Meters Part 4: Plate Constructed Positive Displacement Diaphragm Meters for a Pressure of 350 mbar (5lbf/in2) and up to 170 Cubic Meters (6000 Cubic Feet) per Hour Rating
Includes all amendments and changes through Amendment 1, April 1983
Additional Comments: W/D NO S/S
Published By:British Standards Institution (BSI)
Constructional and performance requirements for badged ratings from 20 m3/h (700 ft3/h).