Vikoll,

The MONDI material is a controlled chemistry composition of ductile iron with pipe barrels made to general requirements of ASTM A 395 Tp 60-42-10 with the pipe spools fabricated to AWWA A 21.51 , while the fittings are to AWWA C 110 of ASTM A 536 grade 70-50-05 with wall thickness equal to C.I. CL250. The acid piping industry uses only a small fraction of the volume of ductile iron of the water works industry, and so it uses the same patterns and molds for the D.I. pipe and fittings castings.

D.I. pipe has different O.D. from steel pipe. The centrifugal pipe casting process allows thicker wall thicknesses to be made for the corrosion requirements of the acid piping industry. The pipe barrels have wall thickness such that pipe I.D. matches fittings I.D. The MONDI piping and fittings have I.D. such that nominal size Nps inches = I.D. inches, for example Nps-12 MONDI has 11.98 inch I.D. (for thick wall corrosion allowance)

The pipe spools and fittings are flanged, so there will be weights at the joints and branch connections. The flanged fitting dimensions are different than steel weld fittings, and the elbows have different radius from steel weld elbows.

The acidpiping.com website used to have more information on the MONDI material properties.

modulus of elasticity 23. x10E6 lb/in2 (1.617 x10E6 Kgf/cm2)
poisson ratio 0.29 - 0.32
specific weight 0.26 lb/in3
Yield strength 42,000 lb/in2 (2953 Kgf/cm2) pipe
50,000 lb/in2 (3515 Kgf/cm2) fittings -Flange
Tensile strength 60,000 lb/in2 (4218 Kgf/cm2) Pipe
70,000 lb/in2 (4921 Kgf/cm2) fittings -Flange
Elongation 10% pipe
5% fittings
Thermal expansion 7.0 x10E-6 inch/inch deg F (32-212 deg F)

Reminder that the strong sulfuric acid has 1.8 specific gravity.