How to choose the right dismantling joint?

Selecting dismantling joints is a crucial step in ensuring the safe and stable operation of pipeline systems. If the selection is inappropriate, it can easily lead to leakage, component damage, and even safety accidents. Therefore, it is necessary to closely combine the actual needs of the pipeline with product compatibility and conduct a comprehensive assessment from multiple dimensions.

I. Core Pipeline Operating Condition Factors​

This serves as the foundation for selection and directly determines the basic adaptability of the joint:​

1. Operating Pressure: The rated pressure of the joint must not be lower than the maximum pressure of the pipeline system, with a safety factor of 1.2-1.5 reserved. For high-pressure scenarios, joints with a rating of PN63 or above should be selected, and the pressure impact resistance of the joint must also be considered.​

2. Operating Temperature: For low-temperature conditions, use low-temperature resistant seals and compatible main body materials. For normal-temperature conditions, select ordinary rubber seals in combination with cast iron or carbon steel. For high-temperature conditions, high-temperature-resistant seals and heat-resistant steel or stainless steel are necessary.

3. Nominal Diameter: The nominal diameter of the joint must be completely consistent with that of the pipeline to avoid connection issues caused by dimensional deviations. For special pipelines, the compatibility of reducing connections should be confirmed in advance.​

4. Medium Characteristics: For non-corrosive media, cast iron/carbon steel with ordinary seals is applicable; for weakly corrosive media, 304 stainless steel with fluororubber seals is recommended; for strongly corrosive media, 316L stainless steel/titanium alloy with perfluoroelastomer/graphite seals should be used; for oils and organic solvents, carbon steel/304 stainless steel with nitrile rubber seals is suitable; for food/pharmaceutical-grade media, materials that meet hygiene standards are required.​

II. Installation Scenario Adaptability Factors

The structure type of the dismantling joint should be selected based on the installation environment and operational requirements:​

1. Space Conditions: Flange-type joints are suitable for scenarios with sufficient space; threaded joints are ideal for narrow spaces and small-diameter pipelines.​

2. Pressure and Risk Level: Welded joints are appropriate for high-pressure and high-risk pipelines; joints with limiting devices are necessary for scenarios with thermal expansion/contraction or displacement restrictions.​

3. Maintenance Frequency: Flange-type joints are preferred for scenarios requiring frequent disassembly of pumps and valves; welded joints can be used for scenarios where one end is fixed and the other end requires maintenance.​

III. Product Performance and Standard Factors

These factors ensure the safety and reliability of the joint:

1. Sealing Performance: The joint must be leak-free under rated pressure, and the seals should not age or deform after long-term use.​

2. Expansion Compensation Capacity: The appropriate axial expansion amount should be selected based on the thermal expansion/contraction of the pipeline or installation errors, with a safety margin reserved.​

3. Compliance with Standards: Priority should be given to products that comply with standards such as GB/T 12465 (domestic) or ISO 7005-1, ANSI B16.5 (international).

In summary, the selection of a dismantling joint should be based on the core operating conditions of the pipeline, and comprehensive decisions should be made by combining installation scenarios, product performance, and post-use services. Only by fully considering all factors can a product with strong adaptability, high safety, and good economy be selected, laying a solid foundation for the long-term stable operation of the pipeline system.