ASTM A234 WP1 / WP5 / WP9
A234 WP1 / WP5 / WP9: Specifications | Grades & Standards | Product Types | Equivalent Grades | Chemical Composition | Mechanical Properties | BW Fittings
ASTM A234 WP1, WP5, WP9 Buttweld Fittings – Global manufacturer and supplier of SA234 WP1, WP5, WP9 elbows, tees, reducers, caps, crosses, stub ends, and pipe bends. High-temperature and high-pressure Cr-Mo fittings for power plants, refineries, boilers, and petrochemical piping systems.
Best Export Prices: sales@midlandforgefittings.com
Midland Forge and Fittings Pvt. Ltd. is a leading manufacturer and global supplier of ASTM A234 WP1, WP5, and WP9 alloy steel fittings. With a strong focus on quality, precision, and reliability, we specialize in producing high-performance elbows, tees, reducers, caps, crosses, stub ends, and pipe bends that meet international standards.
Our state-of-the-art manufacturing facilities and advanced forging technology ensure that every fitting delivers exceptional strength, corrosion resistance, and high-temperature performance, making them ideal for power plants, refineries, boilers, and petrochemical piping systems.
ASTM A234 WP1, WP5, and WP9 are alloy steel grades specified for buttweld pipe fittings used in high-temperature and high-pressure applications. These Cr-Mo (Chromium-Molybdenum) alloy steels provide excellent strength, toughness, and creep resistance at elevated temperatures.
WP1 is a low alloy steel with moderate temperature resistance, WP5 offers improved oxidation resistance with higher Chromium content, and WP9 delivers superior performance for high-temperature service with enhanced Molybdenum content. These grades are commonly available in elbows, tees, reducers, caps, crosses, stub ends, and pipe bends, produced in seamless and welded forms.
A234 WP1/WP5/WP9 fittings comply with ASME B16.9 dimensional standards and are widely used in power generation, refinery, and petrochemical piping systems where durability and reliability under high-pressure steam and hot gas conditions are critical.
Our vision is to be the preferred choice worldwide for ASTM A234 fittings, while our mission is to provide superior quality products with timely delivery and outstanding customer service. We are committed to adhering to global standards, continuous innovation, and sustainable manufacturing practices. Our company policy emphasizes customer satisfaction, technical excellence, and long-term partnerships, ensuring that clients receive reliable and high-performance A234 WP1, WP5, WP9 buttweld fittings for every critical industrial application.
Alloy Steel WP1 Buttweld Fittings Specifications
Cr-Mo Alloy Steel A234 WP5 Fittings– Grades & Standards
| Grade | ASTM Standard | Material Type | Application / Notes |
|---|---|---|---|
| WP1 | ASTM A234 | Alloy Steel Buttweld Fitting | Moderate temperature service, power plant piping |
| WP5 | ASTM A234 | Alloy Steel Buttweld Fitting | High-temperature service, refinery piping |
| WP9 | ASTM A234 | Alloy Steel Buttweld Fitting | High-temperature and high-pressure service, boiler and superheater piping |
Cr-Mo Alloy Steel Fittings: ASTM A234 WP1, WP5, WP9
ASTM A234 WP1 WP5 WP9 Seamless & Welded Fittings - Equivalent Grades
| ASTM Grade | UNS Number | EN / DIN | JIS | GOST / Russian Standard | BS / UK | AFNOR / French Standard |
|---|---|---|---|---|---|---|
| WP1 | K11530 | 15CrMo | SUS 4140 | 12Cr1MoVG | 15CrMo | Z15CrMoV |
| WP5 | K11545 | 5Cr0.5Mo | SUS 405 | 15CrMo | 5Cr0.5Mo | Z5CrMo |
| WP9 | K91540 | 9Cr1Mo | SUS 410 | 12Cr1MoV | 9Cr1Mo | Z9CrMo |
ASTM A234 WP9 Pipe Fittings - Chemical Composition
| Grade | C (%) | Mn (%) | P (%) | S (%) | Si (%) | Cr (%) | Mo (%) | V (%) | Other Elements |
|---|---|---|---|---|---|---|---|---|---|
| WP1 | 0.10 max | 1.0 max | 0.035 max | 0.035 max | 0.30–0.60 | 0.5 | 0.5 | – | – |
| WP5 | 0.10 max | 1.0 max | 0.035 max | 0.035 max | 0.30–0.60 | 5.0 | 0.5 | – | – |
| WP9 | 0.10 max | 1.0 max | 0.035 max | 0.035 max | 0.30–0.60 | 9.0 | 1.0 | – | – |
Alloy Steel A234 WP1 WP5 WP9 Fittings - Mechanical Properties
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Impact Toughness (J) | Hardness (HB) |
|---|---|---|---|---|---|
| WP1 | 485–585 | 205–310 | 20 min | 27 min | 163–207 |
| WP5 | 485–585 | 205–310 | 20 min | 27 min | 163–207 |
| WP9 | 485–585 | 205–310 | 20 min | 27 min | 163–207 |
A234 WP1 WP5 WP9 Alloy Steel Fittings – Available in Seamless and Welded
How does WP9 compare with WP1 and WP5 in terms of long-term creep strength?
WP9 has significantly higher long-term creep rupture strength due to:
Higher Chromium content (9%)
Higher Molybdenum content (1%)
Optimized tempered microstructure
WP1 and WP5 are suitable for moderate temperature service, but WP9 is engineered for high-temperature, high-pressure supercritical boilers and steam lines.
WP9 fittings can operate safely under prolonged exposure to 540–600°C without excessive deformation.
What quality control and testing measures are critical for WP1/WP5/WP9 fittings?
Chemical Analysis: Spectrographic or optical emission testing ensures that Cr-Mo content is within tolerance.
Mechanical Testing: Tensile, yield, elongation, and hardness tests per ASTM A234 standards.
Impact Testing: Charpy V-notch testing for toughness at ambient and elevated temperatures.
Non-Destructive Testing (NDT):
Radiography (RT) or Ultrasonic (UT) for welded fittings
Dye Penetrant (PT) for surface defects
Dimensional Inspection: Ensures compliance with ASME B16.9 for buttweld fittings.
How do WP1 / WP5 / WP9 behave under cyclic thermal loading?
Alloy steels in these grades are designed to handle frequent temperature fluctuations.
Microstructure Stability: Cr-Mo alloys retain mechanical strength without excessive creep or deformation.
Cyclic Fatigue Resistance: Proper heat-treated WP5 and WP9 fittings can withstand repeated steam start-up and shutdown cycles without cracking.
Dimensional Integrity: Maintains shape and tolerances, reducing the risk of leakage or pipe misalignment in high-pressure piping systems.