힌디 어

라오스알바니아암하라어

아르메니아 사람

아제르바이잔

벨라루스어

벵골 사람

보스니아어

불가리아 사람

세부아노

치체와

l Steam pipelines

크로아티아어네덜란드 사람에스토니아 사람

필리핀인

핀란드어

프리지아어	갈리시아	Typical Application
ASTM A192	아이티 섬 사람	하우사어
ASTM A210	헤브라이 사람	몽족
헝가리 인	아이슬란드어	High temperature boilers
자바어	칸나다어	카자흐스탄
크메르	쿠르드족	키르기스

라틴어라트비아 사람리투아니아 사람

룩셈부르크..마케도니아 어

마다가스카르 사람

말레이 사람말라얄람어몰티즈

마오리족마라티어.

몽고 어

버마 사람

네팔어

노르웨이 인

파슈토어

페르시아 인

펀자브어	세르비아 사람
세소토어	싱할라어
슬로바키아 사람	슬로베니아
소말리아어	쇼나
스코틀랜드 게일어	쇼나
신디	순다족

Typical Applications

타지크어

타밀 사람

텔루구어

태국

우크라이나 말우르두어

우즈베크어

베트남 사람웨일스 말.

코사어이디시어.

요루바족

Grade	Application
타타르족	오리야
투르크멘 말	위구르족

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.