Hydrostatic testing of Seamless Boiler Tubes

Seamless boiler tubes are a type of boiler tubes, belonging to the category of seamless steel pipes. The manufacturing method is the same as that of seamless pipes, but there are strict requirements on the types of steel used to manufacture steel pipes.

High-pressure boiler seamless tubes are often in high temperature and high pressure conditions when in use. Under the action of high-temperature flue gas and water vapor, the pipes will oxidize and corrode. Steel pipes are required to have high lasting strength, high oxidation and corrosion resistance, and good organizational stability. High-pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, gas guide tubes, main steam pipes, etc. of high-pressure and ultra-high-pressure boilers.

What is the hydrostatic testing of seamless boiler tubes?

The hydrostatic testing of seamless boiler tubes is divided into two types: working pressure test and overpressure test. The purpose of the water pressure test is to test the strength and tightness of pressure-bearing parts. Generally, after the pressure-bearing parts are overhauled, such as after the replacement or overhaul of certain valves, furnace tubes, headers, etc., as well as after the medium and minor repairs of the boiler, a working pressure test must be carried out. For newly installed boilers, overhauled boilers, and boilers with large-scale replacement of heating surface tubes, an overpressure test of 1.25 times the working pressure should be carried out.

Test preparation

1. Prepare test equipment: pressure gauge, water tank, joints, nuts, etc.

2. Prepare test water: clean tap water or distilled water should be used, and water containing impurities or foreign matter should not be used.

3. Clean the boiler pipe: Before the test begins, the boiler tubes should be cleaned to remove dirt and impurities in the pipe.

Test steps

1. Introduce the test water into the boiler tube and close all valves.

2. Use the pressure gauge to measure the initial pressure in the pipe and record it.

3. Connect the water tank to the boiler pipe through the connecting joint, so that the water in the water tank is slowly injected into the pipe.

4. Observe the pressure in the pipe while filling water until it is full.

5. Close the water inlet valve, wait for the pressure in the pipe to stabilize, use the pressure gauge to measure the pressure in the pipe again, and record it.

6. Remove the connecting joint and drain the test water.

Test result judgment

Judge whether the boiler pipe is qualified based on the initial pressure of the pipe measured during the test, the pressure after filling with water, and whether the pipe leaks during the test.

1. Determine whether the pipeline is leaking: If there is a leak, it should be repaired in time.

2. Determine whether the pipeline is under normal pressure: The pressure in the pipeline should be within the normal range and meet the relevant standard requirements.

3. Determine whether the pipeline is qualified based on the test results: If the pipeline meets the standard requirements, it means that the test is qualified.

Safety precautions

1. During the test, the pressure in the pipeline should be kept stable to avoid sudden pressure increases or decreases.

2. During the water tank filling process, do not inject too much water to avoid overload and cause safety accidents.

3. Pay attention to the safety of the workplace and equipment, and do not conduct the test in places or near facilities that may cause danger.

In short, the water pressure test of seamless boiler tubes is a very important link, and it must be done carefully and meticulously to ensure the long-term stable operation of the equipment.