Hydrostatic test of boiler tubes

Boiler tubes are pipes specially used for conveying high-temperature and high-pressure water, steam or other media in boiler equipment. Carbon steel seamless boiler tubes have higher pressure bearing capacity and safety due to their overall structure without welded joints, and are the core components of high-pressure boiler systems.

Hydrostatic test of boiler tubes is divided into two forms: working pressure test and overpressure test. The purpose of these tests is to test the strength and tightness of pressure-bearing parts

Usually, after the maintenance or replacement of pressure-bearing parts such as valves, furnace tubes, headers, or after small and medium-sized repairs of boilers, working pressure tests must be carried out. For newly installed boilers, overhauled boilers, and boilers with excessive replacement of heating surface tubes, an overpressure test of 1.25 times the working pressure is required.

Test preparation:

1. Prepare test equipment: pressure gauge, water tank, joints, nuts, etc.
2. Prepare test water: clean, 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 pipe should be cleaned to remove dirt and impurities in the pipe.

Test steps:

1. Introduce the test water into the boiler pipe and close all valves.
2. Use a 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, and slowly inject the water in the water tank 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:

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, judge whether the boiler pipe is qualified.

1. Determine whether the pipe is leaking: If there is a leak, it should be repaired in time.
2. Determine whether the pipe is under normal pressure: The pressure in the pipe should be within the normal range and meet the relevant standard requirements.
3. According to the test results, determine whether the pipeline is qualified: if the pipeline meets the standard requirements, it means that the test is qualified.

Safety precautions:

1. During the test, keep the pressure in the pipeline stable to avoid sudden pressure increase or decrease.
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 boiler tube hydrostatic test is a very important link, and it must be done carefully and meticulously to ensure the long-term stable operation of the equipment.

Read more: What are seamless boiler tubes and how are they made? or Carbon steel ERW boiler tube & air heater tube