ASME SA335 P91 Elbow for High-Temperature Piping Solutions

ASME SA335 P91 Elbows are premium alloy steel pipe fittings designed for high-temperature piping systems, compliant with ASME B16.9 standards. These seamless elbows provide exceptional corrosion resistance and erosion resistance, making them ideal for boiler pipeline protection in power plants, petrochemical plants, and refineries.

ASME SA335 P91 elbows are manufactured through hot-forming or cold-forming processes, followed by normalizing and tempering heat treatments to optimize strength and toughness at temperatures up to 650°C. With high chromium (8.00-9.50%), molybdenum (0.85-1.05%), and vanadium (0.18-0.25%) content, they offer superior resistance to oxidation, creep, and wear from corrosive fluids and abrasive slurries. Available in long-radius (LR, R=1.5D), short-radius (SR, R=1D), and reducing configurations, these elbows support angles of 90°, 45°, and 22.5° for versatile industrial piping designs.

These elbows support welding, bending, and flanging, with recommended preheating (200-250°C) and post-weld heat treatment (730-760°C) to ensure weld integrity. Available in sizes from 1/2” to 24” (DN15 to DN600) and wall thicknesses from SCH 40 to SCH 160, they meet diverse pipeline requirements. Rigorous testing, including tensile, flattening, and hydrostatic tests, ensures compliance with ASME SA335 standards for high-temperature and high-pressure service.

Enhanced with coatings like 3LPE, FBE, or galvanizing, ASME SA335 P91 elbows provide superior corrosion resistance, protecting against rust and chemical degradation in extreme environments. Their high creep strength and toughness make them ideal for boiler pipeline protection in power generation, superheaters, and petrochemical processing.

For engineers seeking reliable high-temperature piping solutions, ASME SA335 P91 elbows deliver unmatched durability, safety, and longevity, addressing challenges like pipeline corrosion, thermal stress, and high-pressure demands.

Construction Materials

What is A234 WP11 Fittings?

A234 WP11 Fittings can effectively be bent and welded.

ASME SA 234 wp11 that shape important associations between different pipes of different sizes. Elbow A234 WP11 is the free machining adaptation of this grade, accessible in bar shape for utilizing in automatic screw machines.

W = WELDABLE / wrought
P = RELATED TO P NUMBER OF ALLOY MATERIAL
B = REFER TO MINIMUM YIELD OF MATERIAL

Chemical Composition of ASME SA335 P91 Elbow
Element	Composition (%)
Carbon (C)	0.08-0.12
Manganese (Mn)	0.30-0.60
Phosphorus (P)	≤0.020
Sulfur (S)	≤0.010
Silicon (Si)	0.20-0.50
Chromium (Cr)	8.00-9.50
Molybdenum (Mo)	0.85-1.05
Vanadium (V)	0.18-0.25
Nitrogen (N)	0.030-0.070
Nickel (Ni)	≤0.40
Aluminum (Al)	≤0.04

Mechanical Properties of ASME SA335 P91 Elbow
Property	Value
Tensile Strength, min (MPa)	585
Yield Strength, min (MPa)	415
Elongation, min (%)	20 (Longitudinal)
Hardness, max (HBW)	250

Comparison of ASME SA335 P91 Elbow with Other Fittings
Feature	ASME SA335 P91 Elbow	ASTM A234 WPB Elbow	ASTM A403 WP304 Elbow
Material Type	Alloy Steel	Carbon Steel	Stainless Steel
Temperature Range	High (up to 650°C)	Moderate (-29°C to 425°C)	High (up to 870°C)
Corrosion Resistance	Excellent (High Cr/Mo/V)	Moderate	Superior (Austenitic)
Erosion Resistance	Excellent	Good	Moderate
Creep Strength	Superior	Moderate	Good
Applications	Power Plants, Petrochemical, Refineries	General Piping, Boilers	Food Processing, Marine
Key Advantage	Superior creep strength	Cost-effective strength	Superior corrosion resistance

Alloy Composition Analysis & Application Notes

• Alloy System Identification: The primary alloys listed are 1.25% chromium-0.5% molybdenum (1.25Cr-0.5Mo) steels, classified under ASTM A335 as Grade P11, with carbon content typically 0.10-0.20% (not explicitly shown). These are low-alloy steels designed for high-temperature service (up to 540°C).
• Key Element Roles: - Chromium (1.06-1.30%): Enhances oxidation resistance and forms chromium carbides for creep strength; - Molybdenum (0.48-0.53%): Strengthens the ferrite matrix and improves high-temperature creep resistance; - Trace Elements (V, Co, Cu): Present in minor amounts (<0.2%), with vanadium potentially contributing to carbide strengthening.
• Grade Equivalences: - 1.25Cr-0.5Mo (P11) corresponds to DIN 13CrMo4-5 and EN 10216-2 13CrMo4-5; - C-0.5Mo (P1) is equivalent to DIN 15Mo3 and EN 10216-2 16Mo3 (lower chromium, higher carbon).
• Industrial Applications: Suitable for high-temperature piping in power generation (boiler tubes, superheaters), petrochemical plants (hydrocracking units), and refineries, where resistance to creep and oxidation is critical.
• Variability Note: Composition ranges reflect manufacturing tolerances. The slight variations in element percentages (e.g., Cr 1.06-1.30%) remain within ASTM A335 specification limits, ensuring consistent mechanical properties.

Comparison of ASTM A234 WP11 Elbow with Other Fittings
Feature	ASTM A234 WP11 Elbow	ASTM A234 WPB Elbow	ASTM A403 WP304 Elbow
Material Type	Alloy Steel	Carbon Steel	Stainless Steel
Temperature Range	High (up to 620°C)	Moderate (-29°C to 425°C)	High (up to 870°C)
Corrosion Resistance	Good (Cr/Mo Content)	Moderate	Superior (Austenitic)
Erosion Resistance	Good	Good	Moderate
Creep Strength	Good	Moderate	Good
Applications	Boilers, Petrochemical, Refineries	General Piping, Boilers	Food Processing, Marine
Key Advantage	High-temp creep resistance	Cost-effective strength	Superior corrosion resistance

Key Benefits

Corrosion Resistance

High Cr/Mo/V content protects against oxidation and chemical degradation.

Erosion Resistance

Durable alloy steel withstands wear from abrasive slurries.

High-Temperature Strength

Excels in conditions up to 650°C with superior creep resistance.

Weldability

Supports welding for secure pipeline configurations.

Cost-Effective

Long lifespan reduces maintenance in high-temperature systems.

Versatile Configurations

Available in LR, SR, and reducing designs for diverse applications.

You Can Also Search ASME SA335 P91 Elbows by

A curated list of long-tail keywords for ASME SA335 P91 elbows, covering specifications, applications, and material properties.

Standards and Specifications

• ASME SA335 P91 elbow standards
• ASME B16.9 P91 elbow specifications
• High-temperature P91 elbow properties
• Industrial piping P91 elbow standards

Applications

• ASME SA335 P91 elbows for boiler pipeline protection
• P91 elbows for petrochemical industry
• Industrial piping P91 elbows for oil and gas
• High-temperature P91 elbows for power plants
• Corrosion-resistant P91 elbows for refineries

Material and Grades

• ASME SA335 P91 elbow material
• Corrosion-resistant P91 elbow grades
• High-temperature P91 elbow properties

Manufacturing and Testing

• ASME SA335 P91 elbow manufacturing process
• P91 elbow non-destructive testing
• Corrosion-resistant P91 elbow heat treatment
• Industrial piping P91 elbow quality testing

Procurement and Suppliers

• ASME SA335 P91 elbow suppliers
• Boiler pipeline protection P91 elbow distributors
• Corrosion-resistant P91 elbow price

Dimensions and Customization

• ASME SA335 P91 elbow dimensions
• Industrial piping P91 elbow tolerances
• Custom seamless P91 elbow sizes

Note: ASME SA335 P91 covers alloy steel elbows for high-temperature and corrosion-resistant applications. Contact a certified supplier for detailed specifications.

An ASME SA335 P91 elbow is an alloy steel pipe fitting designed for high-temperature piping systems, offering corrosion resistance and superior creep strength up to 650°C. It is ideal for boiler pipeline protection in industrial piping.

ASME SA335 P91 is an alloy steel grade with high Cr/Mo/V content for superior corrosion resistance and creep strength at high temperatures (up to 650°C). ASTM A234 WPB is a carbon steel grade for moderate temperatures (-29°C to 425°C) with lower cost but less high-temperature performance.

P91 elbows are available in 90°, 45°, and 22.5° angles, with 60° and 120° options for specialized industrial piping systems, ensuring flexibility in high-temperature applications.

A reducing P91 elbow connects pipes of different diameters, available in LR (R=1.5D) or SR (R=1D) configurations. It ensures corrosion resistance and high-temperature performance in complex industrial piping layouts.

ASME SA335 P91 elbows are made from alloy steel with high chromium (8.00-9.50%), molybdenum (0.85-1.05%), and vanadium (0.18-0.25%) for enhanced corrosion resistance and creep strength in high-temperature industrial piping.

P91 elbows are produced via hot-forming or cold-forming, followed by normalizing and tempering to ensure corrosion resistance and strength for high-temperature piping.

Quality is ensured through: - Back Arc Thickness: Measured with a thickness gauge to detect thinning.
- Dimensional Checks: Inner/outer diameters and center height.
- Radiographic Inspection: Detects defects like pores or slag inclusions.
- Testing: Tensile, flattening, and hydrostatic tests per ASME SA335.

P91 elbows offer superior creep strength and corrosion resistance at high temperatures (up to 650°C), making them ideal for boiler pipeline protection in demanding industrial piping applications.

Coatings include: - Light oiling
- Black painting
- FBE coating
- 3LPE coating
- Hot-dip galvanizing
These enhance corrosion resistance for boiler pipeline protection.

Calculate the back arc length: L = D * 3.14 (D = pipe diameter). For alloy steel: Weight (kg) = (D * a * 0.02466 * L) / 1000, where a is wall thickness. This ensures accurate sizing for industrial piping.

Chemical Composition & Mechanical Properties

Chemical Composition of ASTM A335 P91
Element	Composition (%)
Carbon (C)	0.08–0.12
Manganese (Mn)	0.30–0.60
Phosphorus (P)	≤0.02
Sulfur (S)	≤0.01
Silicon (Si)	0.20–0.50
Chromium (Cr)	8.00–9.50
Molybdenum (Mo)	0.85–1.05
Vanadium (V)	0.18–0.25
Niobium (Nb)	0.06–0.10
Nitrogen (N)	0.03–0.07

Mechanical Properties of ASTM A335 P91
Property	Value
Tensile Strength (MPa)	585 min
Yield Strength (MPa)	415 min
Elongation (%)	20 min
Hardness (HBW)	≤250

ASTM A335 P91 Type1 VS Type2
Grade	UNS Designation	Chemical Composition %
P91 Type 1	K91560	C	Mn	P	S	Si	Ni	Cr	Mo
		0.08-0.12	0.30-0.60	0.020	0.010	0.20-0.50	0.40 max	8.00-9.50	0.85-1.05
		V	N	Al	Cb	Ti	Zr	Sn	Sb
		0.18-0.25	0.030-0.070	0.02 max	0.06-010	0.01 max	0.01 max	_	_
P91 Type 2	K91560	C	Mn	P	S	Si	Ni	Cr	Mo
		0.08-0.12	0.30-0.50	0.020	0.005	0.20-0.40	0.40 max	8.00-9.50	0.85-1.05
		V	N	Al	Cb	Ti	Zr	Sn	Sb
		0.18-0.25	0.035-0.070	0.02 max	0.06-0.10	0.01 max	0.01 max	0.010 max	0.003 max

ASTM A335 P91 Type 1 & Type 2 have subtle differences mainly in elements Mn, S, Si, N, Sn and Sb content, and Type 2 has stricter requirements on element content than Type 1. P91 type 1 and 2 shall have a hardness within the range of 190 to 250 [HBW] or 196 to 265 [HV] or 91 HRBW to 25 HRC.

ASME SA335 P91 Elbow

ASME SA335 P91 Elbow

ASME SA335 P91 Elbow for High-Temperature Piping Solutions

What is A234 WP11 Fittings?

Alloy Composition Analysis & Application Notes