About Duplex / Super Duplex Steel Flanges
Tesco Steel & Engineering manufactures and supplies Duplex Flanges and Super
Duplex Steel flanges for piping work in oil and gas, petrochemical, and power
plants. We produce these in grades S31803, S32205, S32750, and S32760. Types include
weld neck, slip-on, socket weld, blind, lap joint, and RTJ. A Duplex Steel flange
connects pipes, valves, and pumps, and lets you get in for cleaning or inspection
without pulling the whole line apart.
Which flange you need depends on the connection type, pressure and temperature
rating, facing, and material. We produce Super Duplex flanges to ASME B16.5 and
B16.47 dimensions. Sizes go from ½ inch NB up to 48 inch NB, pressure classes
150 through 2500. If you need something outside standard sizing, we can work to
custom dimensions too.
We work with dual-phase steel, meaning it has both austenitic and ferritic structure
in the metal. That gives it more strength than regular stainless and better
resistance to chloride stress cracking. Super duplex grades like S32750 and S32760
have PREN values above 40. This is why they get used in seawater equipment, offshore
drilling parts, and gas processing lines, basically anywhere chloride exposure is
constant.
Forging and machining is done on CNC equipment, checked at each stage. Tolerances
stay within ASME B16.5 across all sizes. Before anything ships, our quality team
runs hydrostatic testing, ultrasonic testing, PMI, and dye penetrant checks on every
batch. Mill test certificates go out with each shipment, referencing ASTM A182 or
A815 depending on the grade.
