Hindski

LaoAlbanskiAmharski

Armenski

Azerbejdžanski

Bjeloruski

Bengalski

Bosanski

bugarski

Cebuanski

Čičeva

l Steam pipelines

hrvatskiholandskiEstonski

Filipinski

Finski

Frizijski	galicijski	Typical Application
ASTM A192	haićanski	Hausa
ASTM A210	Hebrejski	Hmong
Mađarski	Islandski	High temperature boilers
Javanski	Kannada	Kazaški
Kmerski	Kurdski	Kirgizi

LatinskiLatvijskiLitvanski

Luksemburg..Makedonski

Madagaskarski

MalajskiMalajalamskiMalteški

MaoriMarati.

Mongolski

Burmanski

Nepalski

Norveški

Paštunski

perzijski

Pandžapski	Srpski
Sesoto	Sinhalski
Slovački	Slovenski
Somalijski	Šona
Škotski galski	Šona
Sindhi	Sundanski

Typical Applications

Tadžikistanski

Tamilski

Telugu

Tajlandski

UkrajinskiUrdu

Uzbekistanski

VijetnamskiVelški.

KosaJidiš.

Joruba

Grade	Application
Tatarski	Oriya
Turkmenski	Ujgur

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.