Hindi

LaoAlbanèAmharik

Amenyen

Azerbaydjanyen

Belarisyen

Bengali

Bosnyen

Bilgaryen

Sebuano

Chichewa

l Steam pipelines

KwoasyenOlandèEstonyen

Filipin

Finnish

Frisyen	Galisyen	Typical Application
ASTM A192	Ayisyen	Aoussa
ASTM A210	Ebre	Hmong
Ongwa	Islandè	High temperature boilers
Javanè	Kannada	Kazak
Khmer	Kurd	Kirghiz

LatinLetonyenLityanyen

Liksanbou..Masedonyen

Malgach

MalayMalayalamMaltèz

MaoriMarathi.

Mongolyen

Birman

Nepalè

Nòvejyen

Pachto

Pèsyen

Punjabi	Sèb
Sesotho	Sinhala
Slovak	Slovenyen
Somali	Shona
Gaèlik Ekosè	Shona
Sindhi	Soundanès

Typical Applications

Tajik

Tamil

Telugu

Thai

IkrenyenOurdou

Ouzbèk

VyetnamyenGalwa.

XhosaYidich.

Yoruba

Grade	Application
Tatar	Oriya
Turkmen	Ouïgour

Typical Applications

l Boiler superheater tubes

l Steam pipelines

l Heat exchanger tubes

l Industrial boilers

Because of its higher strength, ASTM A210 tubes are widely used in medium-temperature boiler systems.

Womic Steel manufactures ASTM A210 seamless tubes using advanced cold drawing and heat treatment processes, ensuring consistent mechanical properties.

5 ASTM A335 Alloy Steel Boiler Pipes

For high-temperature power plant systems, alloy steel pipes specified by ASTM A335 are commonly used.

These pipes provide excellent creep resistance and oxidation resistance at elevated temperatures.

Common ASTM A335 Grades

Grade	Alloy Type	Application
P11	Cr-Mo alloy steel	Medium temperature boilers
P22	Cr-Mo alloy steel	High temperature boilers
P91	Advanced alloy steel	Ultra-supercritical power plants
P92	High creep resistance alloy	Advanced power plants

6 Comparison of P11, P22, and P91 Alloy Steel Pipes

Property	P11	P22	P91
Alloy Elements	Cr-Mo	Cr-Mo	Cr-Mo-V-Nb
Temperature Resistance	Medium	High	Very High
Creep Resistance	Moderate	Good	Excellent
Typical Application	Industrial boilers	Power plants	Ultra-supercritical boilers

P11

Used in medium-temperature steam pipelines and industrial boilers.

P22

Provides improved high-temperature strength, commonly used in power plant superheater systems.

P91

A modern high-performance alloy steel used in ultra-supercritical power plants, capable of operating at extremely high temperatures and pressures.

Womic Steel manufactures ASTM A335 P11, P22, and P91 seamless pipes with advanced heat treatment and strict metallurgical control, ensuring reliable performance in high-temperature boiler systems.

7 Seamless Boiler Tube Manufacturing Process

High-quality boiler tubes require advanced production technology.

Typical manufacturing steps include:

l Steel Billet Selection
High-quality billets are selected for tube production.

l Hot Piercing and Rolling
Creates seamless hollow tubes.

l Cold Drawing Process
Improves dimensional precision and surface finish.

l Heat Treatment
Normalizing, tempering, or annealing depending on material grade.

Inspection and Testing

l Quality tests include:

l Ultrasonic testing

l Hydrostatic testing

l Eddy current testing

l Chemical composition analysis

l Mechanical property testing

Womic Steel uses modern production lines and strict inspection procedures, ensuring every boiler tube meets international quality standards.

8 Dimensional Accuracy and Tube Precision

For boiler tubes, dimensional precision is critical to ensure safe operation and proper installation.

Parameter	Typical Control
OD tolerance	±0.05 – ±0.10 mm
Wall thickness	±7.5%
Straightness	≤1/1000
Ovality	≤50% of OD tolerance

Cold drawn precision tubes provide excellent dimensional control, making them suitable for high-performance boiler systems.

9 Selecting the Right Boiler Tube Material

When choosing boiler tube materials, engineers must consider:

l Operating temperature

l System pressure

l Corrosion environment

l Heat transfer requirements

l Cost and availability

Typical selection guidelines include:

l ASTM A192 for standard high-pressure boilers

l ASTM A210 for superheater tubes

l ASTM A335 P11/P22 for high-temperature pipelines

l ASTM A335 P91 for ultra-supercritical power plants

A reliable boiler tube manufacturer can provide technical support for material selection and project design.