Intelligent Insulation Bright Annealing Machine

Water Pressure /Atmosphere pressure monitoring

Excellent Designed Air sealing spare parts

Thermocouple temperature measurement

Cooling Protection Tunnel

Process Flow

Bright Annealing pipe is crafted through heat-treating (annealing) steel using a controlled protective 

atmosphere furnace. Post heat-treatment, the steel exhibits a mirror-like, reflective finish, 

though minor imperfections and cloudiness may occur. This bright annealing stainless steel can be 

further polished to achieve a more reflective surface, ideal for applications requiring high reflectivity.

Our online fixed welding (annealing) equipment heats the stainless steel welded pipe to 1050°C, then uses 

Hangao's proprietary resistance heating method to uniformly reach 1050°C (adjustable from 1-1200°C) 

within the insulation furnace, ensuring extended pipe insulation and solution treatment time, further improving pipe 

performance on standard models.

Three thermocouples are used to measure temperatures at multiple points within the furnace to ensure 

uniform temperature distribution within the furnace chamber, achieving a controllable temperature 

accuracy of ±2°C.

1. Constant temperature：

The temperature detection of the insulation section is achieved by directly inserting high-precision high-temperature resistant platinum rhodium type thermocouples into the furnace to detect the actual temperature inside the furnace. The intelligent temperature controller achieves precise closed-loop control through PID calculation, and the temperature can be accurately within ±2 ℃.

2. Easy installation：

There is no need to replace the quartz tube, which is convenient for maintenance and saves installation time.

3. Energy saving：

Rated power: 9-12KW, temperature rise to 1050 ℃ at room temperature for about 15 minutes. After reaching the insulation temperature of 1050, the insulation section only needs a current of 5-8A to maintain the temperature, and the actual output power will not be increased due to the size of the steel pipe and the increase in production line speed.

4. More humanized：

After setting the insulation temperature once, the insulation section will not need to be manually adjusted due to changes in the size of the steel pipe and the speed of the production line.

Company Advantages

Established: 2020

Core Expertise: Over 20 years of experience in welded pipe equipment.

Factory Size:  Over 20,000 square meters of modern production base and warehouse.

Technical Team: Equipped with over 20 professional technicians dedicated to R&D and innovation.

Core Products: Precision welded pipe production lines, welding leveling equipment, bright solution equipment, 

weld seam tracking systems, intelligent control systems, finishing rolling pipe bright solution equipment, 

rotary annealing equipment, etc.

R&D Strength: Holds over 30 national patents and continuously obtains new patent authorizations.

Certifications: National high-tech enterprise, certified with ISO9001 quality management system, 

ensuring quality throughout the entire process from design to service.

Partners: Our relentless pursuit of excellence has earned the trust of numerous industry-leading companies, including Juli, Wujin, Sanhua, Plymouth (USA), and Binner (India).

Market Coverage: Our products are sold globally, exported to numerous countries and regions besides China, including Dubai, Russia, India, South Korea, Thailand, Pakistan, and Vietnam.

FAQ

Q1: Why does stainless steel welded tubing need bright annealing?

A1:Bright annealing can relieve residual stress generated during forming and welding while improving material properties and surface condition. It is an important downstream process for many high-quality sanitary and precision stainless steel tubes.

Q2: What properties of stainless steel tubes can bright annealing improve?

A2: Bright annealing can improve microstructural uniformity, mechanical properties, corrosion resistance, and surface quality while reducing residual stresses caused by welding and forming.

Q3：How does bright annealing prevent oxidation on stainless steel tube surfaces?

A3：Bright annealing prevents oxidation by using a controlled protective atmosphere and precisely managing heating, soaking, and cooling. Hydrogen and nitrogen mixtures are commonly used as protective gases.

Q4: How does a bright annealing line control annealing temperature?

A4: Annealing temperature is controlled through heating power, temperature sensors, soaking-zone control, and cooling systems. Hangao's bright annealing equipment uses intelligent temperature control for accurate heating and cooling management.

Q5:  Can welding, annealing, and sizing be integrated into one tube mill line?

A5: Yes. A continuous tube mill can integrate forming, welding, weld treatment, sizing, bright annealing, cutting, and inspection. Hangao's product portfolio covers these key processes and can be configured into a complete production line according to customer requirements.