The 1954 Rules of Proof Highest Mean Service Pressure equivalent transducer values as converted from LUP by Burrards formula:
3 tons = 8,960 psi
3 1/4 tons = 9,800 psi
3 1/2 tons = 10,640 psi
4 tons = 12,320 psi
Conversion provided by the Birmingham Proof House 2001 - similar but as Miller observed less so with increasing pressures
3 tons = 8,938 psi
3 1/4 tons = 9,682 psi
3 1/2 tons = 10,427 psi
4 tons = 11,917 psi
Mr. Roger Hancox, Proof Master, Birmingham Proof House, 2008
A basic Rule of Thumb conversion of tons to CIP transducer pressure (is) multiplying the tons per sq inch by 2240 to obtain psi, and then by a factor of 1.33 to obtain the approximate CIP pressure.
INTERESTING
3.5 tons X 2240 = 7840 X 1.33 = 10,427
4 tons x 2240 = 8960 X 1.33 = 11,917
It appears that the proof house simply converted the numbers and did not do simultaneous transducer tons and transducer psi, kg/cm2, or BAR measurements!
