Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.

Buttweld Fittings

ASTM A234 WP5 Fittings

5% Chromium – 0.5% Molybdenum alloy steel buttweld fittings for refinery heaters, cracking units and high-sulphur, high-temperature service.

ASTM A234 / ASME SA234 1/2" – 24" NB EN 10204 3.1 MTC
5Cr-0.5Mo Grade

ASTM A234 WP5 Alloy Steel Buttweld Fittings

Tubewell Steel & Engg. Co. manufactures, stocks and supplies ASTM A234 WP5 fittings from Mumbai – a 5Cr-½Mo ferritic alloy grade designed for hot hydrocarbon and high-sulphur service. WP5 elbows, tees, reducers and caps are the matching fittings for A335 P5 pipes in refinery furnaces and cracking units.

StandardASTM A234 / ASME SA234
GradeWP5 Cl.1 / Cl.3 (UNS K41545)
Size Range1/2" NB – 24" NB
ScheduleSCH 10 – SCH XXS

Product Overview

Why WP5 is specified for hot, sulphur-bearing hydrocarbon service

ASTM A234 WP5 is a wrought ferritic alloy steel fitting grade containing 4.0–6.0% chromium and 0.44–0.65% molybdenum. The high chromium content gives WP5 much better resistance to high-temperature sulphidation and oxidation than 1¼Cr or 2¼Cr grades, while molybdenum provides creep strength. This combination makes WP5 the standard choice for refinery heater outlets, crude and vacuum unit transfer lines and other hot oil service where sulphur compounds are present.

WP5 fittings are supplied in the annealed or normalized and tempered condition, in Class 1 or the higher-strength Class 3. We offer seamless and welded (WPW) elbows, tees, reducers, caps and stub ends to ASME B16.9 and B16.28, bevelled per ASME B16.25 and fully traceable to the heat. Each lot carries an EN 10204 3.1 certificate, with 3.2 certification and TPI available on request.

  • Excellent sulphidation resistance
  • Good creep strength up to about 650°C
  • Matches A335 P5 pipe and A182 F5 forgings
  • Available in Class 1 and Class 3
  • Seamless and welded construction
  • 100% PMI before dispatch

Specifications

Standard supply range for ASTM A234 WP5 fittings

ParameterDetails
StandardASTM A234, ASME SA234
GradeWP5 Class 1, WP5 Class 3 (UNS K41545); WPW5 for welded
Dimension StandardASME B16.9, ASME B16.28, MSS SP-43
Size (NB)Seamless: 1/2" NB to 24" NB; Welded: 2" NB to 48" NB
Wall ThicknessSCH 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS
Elbows45°, 90° and 180° – Long Radius (1.5D) and Short Radius (1D)
Bending RadiusR = 1D, 1.5D, 2D, 3D, 5D and custom pipe bends
Tees & CrossesEqual Tee, Reducing Tee, Equal Cross, Reducing Cross
ReducersConcentric Reducer, Eccentric Reducer
Other TypesPipe Cap, Stub End (Long / Short pattern), Return Bend
ManufacturingSeamless (WP) and Welded (WPW) – hot formed / cold formed
Heat TreatmentFull / Isothermal Annealed or Normalized & Tempered
EndsBevelled Ends as per ASME B16.25
CertificatesEN 10204 3.1 / 3.2, NACE MR0175, TPI Reports

Material Grades & Equivalents

International equivalents of A234 WP5

GradeASTM / ASMEUNSENW.Nr.JISMatching Pipe / Forging
WP5A234 / SA234 WP5K41545X11CrMo51.7362STPA 25A335 P5 / A182 F5

Chemical Composition

Weight %, as per ASTM A234

CCarbon≤ 0.15
MnManganese0.30–0.60
PPhosphorus≤ 0.040
SSulphur≤ 0.030
SiSilicon≤ 0.50
CrChromium4.0–6.0
MoMolybdenum0.44–0.65
GradeCMnPSSiCrMo
A234 WP50.15 max0.30 – 0.600.040 max0.030 max0.50 max4.0 – 6.00.44 – 0.65

Mechanical Properties

Values at room temperature as per ASTM A234

GradeTensile StrengthYield Strength (min)Elongation (Long.)Elongation (Trans.)Hardness (max)
WP5 Cl.1415 – 585 MPa (60 – 85 ksi)205 MPa (30 ksi)30%20%217 HB
WP5 Cl.3485 – 655 MPa (70 – 95 ksi)275 MPa (40 ksi)22%14%217 HB
415MPa
Min. Tensile Strength (Cl.1)
205MPa
Min. Yield Strength (Cl.1)
30%
Min. Elongation (Cl.1)

Physical Properties

Typical values (for reference)

PropertyMetricImperial
Density7.70 g/cm³0.278 lb/in³
Melting Range1450 – 1510 °C2640 – 2750 °F
Modulus of Elasticity205 GPa29.7 × 10³ ksi
Thermal Conductivity (100°C)33 W/m·K19.1 BTU/h·ft·°F
Mean Thermal Expansion (20–300°C)11.9 µm/m·°C6.6 µin/in·°F
Specific Heat0.46 J/g·°C0.11 BTU/lb·°F
Max. Service Temperature≈ 650 °C≈ 1200 °F

Dimension Chart

As per ASME B16.9 – center-to-end / end-to-end dimensions in mm

Showing standard sizes. Other sizes available on request.
NPSOD at Bevel90° LR Elbow (A)45° LR Elbow (B)Tee (C / M)180° LR Return (O)Cap (E)Reducer (H)
1/2"21.33816257625–
3/4"26.7381929762538
1"33.4382238763851
1 1/4"42.2482548953851
1 1/2"48.35729571143864
2"60.37635641523876
2 1/2"73.09544761903889
3"88.911451862295189
4"114.31526410530564102
5"141.31907912438176127
6"168.32299514345789140
8"219.1305127178610102152
10"273.1381159216762127178
12"323.9457190254914152203
14"355.65332222791067165330
16"406.46102543051219178356
18"457.06862863431372203381
20"508.07623183811524229508
22"559.0838343419–254508
24"610.09143814321829267508

All dimensions in mm. A, B, C/M = center-to-end; O = center-to-center; E = cap length (for standard wall); H = reducer end-to-end. Wall thickness is matched to the specified pipe schedule.

Applications

Where ASTM A234 WP5 fittings are used

Refinery Heaters

Fired heater outlet and crossover piping in crude and vacuum units.

Cracking Units

Delayed coker, visbreaker and thermal cracker transfer lines.

Hydroprocessing

Hydrotreater and hydrocracker piping exposed to H₂ and H₂S.

Hot Oil Lines

High-temperature hydrocarbon lines with sulphur-bearing feedstock.

Heat Exchangers

Inlet and outlet connections on high-temperature exchangers.

Petrochemicals

Furnace and reactor effluent piping in petrochemical complexes.

Testing & Why Choose Us

Quality you can verify on every heat

Ready Stock

Large inventory for fast dispatch

Certified Material

MTC EN 10204 3.1 / 3.2

100% PMI

Positive material identification

On-time Delivery

Pan-India & export shipping

Radiography Test Ultrasonic Test Dye Penetrant Test Magnetic Particle Test Hardness Test Tensile Test Macro / Micro Test Dimensional Inspection

Frequently Asked Questions

Quick answers about A234 WP5 fittings

WP5 contains 4.0–6.0% chromium and 0.44–0.65% molybdenum with carbon limited to 0.15% max and silicon to 0.50% max. It is the fitting equivalent of A335 P5 pipe and A182 F5 forgings.

Chemistry is the same; the difference is strength. Class 1 requires 415–585 MPa tensile and 205 MPa minimum yield, while Class 3 requires 485–655 MPa tensile and 275 MPa minimum yield.

WP5 is preferred where sulphidation is the governing damage mechanism – for example hot crude, vacuum residue and coker lines. Its 5% chromium gives far better resistance to sulphur attack at temperature than 1¼Cr or 2¼Cr grades.

Yes. WP5 is an ASME P-No. 5B material, so preheat of around 200°C and post-weld heat treatment typically in the 705–760°C range are specified by ASME B31.1 / B31.3, depending on wall thickness.

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