Ace Alloys LLP

ASTM A234 WP91 tees are high-strength alloy steel buttweld fittings from Grade WP91 chrome-moly steel, designed for extreme high-temperature and high-pressure applications in power plants and supercritical boilers.​

Chemical Composition

WP91 contains 0.08-0.12% carbon, 0.30-0.60% manganese, ≤0.40% silicon, 8.00-9.50% chromium, 0.85-1.05% molybdenum, 0.18-0.25% vanadium, plus niobium 0.06-0.10%, nitrogen 0.03-0.07%, and Al≤0.02% for superior creep rupture strength.​

Mechanical Properties

These tees achieve minimum tensile strength of 585 MPa, yield strength of 415 MPa, and 20% elongation, with normalized and tempered condition enabling service up to 650°C and pressures to 9000 LBS.​

Dimensions and Standards

Equal or reducing tees conform to ASTM A234/ASME SA234 and ASME B16.9, sized ½” to 48” NB in Sch 10s/40s/80s/160s/XXS, seamless construction with BE ends for welding to A335 P91 pipes.​