Product description:

High-pressure boiler steel pipes are steel pipes formed by punching through round steel, with no welds on the surface. According to the production method, seamless steel pipes are divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, and hot-expanded seamless steel pipes. Seamless steel pipes are classified into two types based on their cross-sectional shape: circular and special-shaped.

ASME SA335 High-pressure boiler tube is a seamless ferritic alloy steel tube specifically designed for high-temperature and high-pressure service, such as in boilers, superheaters, heat exchangers, and power plant piping systems. Manufactured according to the ASME SA335 / ASTM A335 specification, these tubes offer superior strength, heat resistance, and corrosion protection, making them ideal for long-term use in power generation and industrial applications.

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Standard Overview

The ASME SA335 standard covers seamless ferritic alloy-steel pipes intended for high-temperature service. It ensures that all tubes meet strict requirements for mechanical strength, heat resistance, and chemical composition to perform reliably in severe thermal and pressure environments.

Common grades include:

P1, P2, P5, P9, P11, P12, P22, P91, and P92

Each grade provides a unique balance of creep strength, oxidation resistance, and thermal stability. For example, Grade P22 is widely used for high-pressure boilers and heat exchangers, while Grade P91 is known for excellent creep resistance and high-temperature strength.

Manufacturing Process

The production of ASME SA335 high-pressure boiler tubes follows a precise, high-quality manufacturing process to ensure uniform structure and superior mechanical properties:

Raw material selection: Premium alloy steel billets containing chromium, molybdenum, and vanadium.

Hot extrusion or hot rolling: Forms seamless tubes without welds.

Cold drawing (optional): Enhances dimensional accuracy and surface quality.

Heat treatment (normalizing, quenching, and tempering): Optimizes microstructure for strength and ductility.

Non-destructive testing: Includes ultrasonic, eddy current, and hydrostatic tests for quality assurance.

Surface finishing: Tubes are oiled, varnished, or black-painted to prevent oxidation and corrosion.

This process results in a seamless alloy steel tube capable of operating in temperatures exceeding 600°C and under extreme pressure conditions.

Key Features

High-temperature strength: Excellent creep and rupture resistance in prolonged high-heat exposure.

Superior corrosion and oxidation resistance: Suitable for steam, flue gas, and corrosive atmospheres.

Excellent mechanical stability: Maintains dimensional accuracy under thermal stress.

Seamless structure: Ensures consistent pressure-bearing capacity and safety.

Long service life: Designed for continuous operation in harsh industrial environments.

Customizable options: Available in multiple grades, wall thicknesses, and finishes.

Applications:

The application scope of seamless steel pipes is very wide, including structures, fluid transportation, low to medium pressure boilers, high-pressure boilers, fertilizer equipment, petroleum cracking, geological drilling, diamond core drilling, petroleum drilling, ships, automotive half-shaft sleeves, diesel engines, etc. The use of seamless steel pipes will ensure no leakage problems, guarantee the usage effect, and improve material utilization. It can be seen that the application of seamless steel pipes mainly covers three major fields. The first is the construction field, which can be used for underground pipeline transportation, including extracting groundwater during construction. The second is the processing field, which can be used for mechanical processing, bearing sleeves, etc. The third is the electrical field, including gas pipelines and fluid pipelines for hydropower generation.

ASME SA335 high-pressure boiler tubes are extensively used in industries where safety, reliability, and high performance are crucial, such as:

Power generation plants: Superheater tubes, reheater coils, and steam pipelines.

Petrochemical and refinery industries: High-temperature heat exchangers and furnace systems.

Boilers and pressure vessels: Structural components exposed to high steam pressure.

Nuclear and thermal power stations: High-efficiency power piping systems.

Industrial and marine boilers: High-performance heat transfer systems.

Their superior alloy composition ensures long-term resistance to scaling, creep, and oxidation in high-pressure environments.

Company profile:

Since its establishment in 2014, Wuxi Hengxin Zhicheng Co., Ltd. has rapidly grown into a leading enterprise in the steel manufacturing industry. We focus on the research, production and sales of seamless steel pipes, special-shaped steel pipes and hydraulic cylinders, and are committed to providing customers with high-quality, customizable products that fully meet diverse application needs.

Our products are exported to global markets such as the Middle East, South America, Africa, and Southeast Asia, and are highly trusted by large purchasers and customers in the steel industry. We always prioritize quality, reliability and customer service, and attach great importance to establishing long-term and stable cooperative relationships with customers. We provide each customer with tailor-made solutions.

We continuously promote technological innovation and improve service capabilities and production efficiency. Through an efficient online platform, you can browse our best-selling products at any time and communicate with the sales and support teams in real time to conveniently obtain the information you need. We sincerely invite partners from all countries to visit, exchange and provide guidance, and jointly explore more possible cooperation opportunities!

Certification:

Packaging and Transportation:

【Package standard】

We use steel bands to tightly package the products into hexagonal bundles. The structure is stable and not prone to deformation. Each bundle is equipped with two high-strength nylon straps to ensure the safety and convenience of the lifting operation.

To meet various maritime transportation needs, we offer a range of customized packaging options, including full coverage with oilcloth, moisture-proof wooden boxes, and high-strength protective frame packaging, to ensure the maximum safety of goods during transportation.

【Guarantee for transportation】

We offer 20-foot and 40-foot standard container transportation services. Each container can carry up to 25 tons of goods and we can accept trial orders with a minimum of 5 tons. This allows for flexible adaptation to your purchasing scale. All packaging complies with maritime shipping standards to ensure that the goods are delivered to the destination efficiently and safely.

Why us?

We focus on the research, development, production and sales of seamless steel pipes, special-shaped steel pipes and hydraulic cylinders. We have a complete production chain and an advanced equipment system, including piercing machines, cold drawing machines, hot rolling machines, high-precision flaw detection and testing equipment. The company has passed multiple authoritative certifications such as ISO9001, API, SGS, CCS, DNV, ABS, CE, RoHS, etc., ensuring that each product complies with international standards. We are committed to providing customers with high-quality, customizable solutions to meet diverse application needs.

Relying on our own built processing base and modern workshops, combined with multiple branches and storage centers across the country, we have achieved sufficient inventory and efficient logistics coordination, significantly shortening the delivery cycle and ensuring the rapid delivery of orders.

We have established a complete service and support system. After the order is signed, the professional after-sales team can provide timely and safe on-site guidance and technical support to ensure that customers are at ease throughout the process from procurement to use.

FAQ：

1. Do you support customized design and production?

Sure. We have a professional engineering team that can conduct customized design and production with special sizes, control systems or OEM according to your requirements.

2. How fast can you deliver?

In stock sizes, it takes 3-5 days. For customized sizes, it takes 30-35 days.

3. What payment methods do you support?

We support TT payment. Generally, 30% to 50% of the payment is made in advance, and the remaining amount is paid before shipment.

4. Can you provide material certification (MTC)?

Yes, we will provide MTC to you after production is completed to ensure that the material quality meets the standards.

5. What is the minimum order quantity?

Generally, we accept trial orders. The minimum order quantity is 1-3 tons, which can be determined according to different products.