Introduction to Common Connector Structures for Radiator Air Tightness Leak Detection

Radiator air tightness test connectors are crucial for completing inspections quickly and accurately. They enable rapid and sealed connections with radiator nozzles during testing. Below is an introduction to commonly used air tightness connectors in the industry:

1.External Expansion Connector
This type seals by expanding inside the nozzle and is suitable for heat exchangers and injection-molded pipe fittings. It accommodates a wide range of nozzle sizes but requires smooth inner wall surfaces of the nozzle. Locking is necessary for high-pressure applications, and it is easy to operate. See Figure 1 below:

2.Internal Clamp Connector
This connector seals by clamping from the outside of the pipe and is designed for pipes with clearly defined outer diameters, such as copper, aluminum, or steel pipes. It features a pressure-assisted self-tightening design with hardened locking teeth to prevent detachment. This type imposes strict requirements on the outer diameter of the pipe. See Figure 2 below:

3.Threaded Connection Connector
This connector screws onto threaded ports on the radiator, which may be standard threads (e.g., ½", ¾", or 1") or non-standard threads. It is suitable for high-pressure testing, with threaded teeth ensuring a secure connection. However, frequent use may lead to wear. To prolong its service life, copper materials can be used for manufacturing. See Figure 3 below:

4.Special-Shaped Nozzle Connector
Designed to encase non-standard or non-circular nozzles externally, this connector is ideal for automotive radiators or other applications with uniquely shaped nozzles. It features a sliding sleeve mechanism for quick operation and is lined with soft materials to protect the workpiece surface. See Figure 4 below:

When selecting an appropriate air tightness test connector, the following factors should be considered comprehensively:

1.Interface Type as the Foundation:
First, identify the type of radiator nozzle—whether it is internal, external, threaded, or a special-shaped port. This directly determines the sealing method required for the connector.

2.Pressure Range for Safety:
Clearly define the range of test pressure. Different connectors have different pressure resistance limits. For instance, some are suitable for low-pressure applications (around 0.2 MPa), such as radiators for water tanks or intercoolers, while others are designed for high-pressure environments, such as hydraulic oil radiators, air conditioning evaporators, or battery cooling systems. Ensure the connector meets the required test pressure during design.

3.Efficiency and Adaptability:
In scenarios emphasizing efficiency, such as production lines, ease of operation is critical. For example, connectors with handle-operated or sliding sleeve designs often enable quick connection and disconnection. If the production line involves diverse product models (e.g., small-batch, multi-variety production), the connector's versatility (ability to cover a range of sizes) or the ease of changing tooling should also be considered.

4.Material and Durability:
The main body material of the connector (e.g., aviation aluminum, stainless steel) affects its strength and durability. The sealing ring material (e.g., chloroprene rubber) should be compatible with the testing medium (gas) and suitable for the operational temperature range.

In the automotive radiator manufacturing sector, quick-seal connectors significantly improve the efficiency of leak detection processes. For the special-shaped nozzles commonly found on radiators, specialized externally-wrapped quick connectors are available. Their sliding sleeve design and soft internal lining enable instant sealing while protecting the product surface.

Furthermore, the industry is continuously advancing technologically. For example, some companies have patented connector structures that utilize bidirectional screws and inclined groove designs to drive clamping blocks, enhancing both installation/removal performance and sealing effectiveness. Other patents address safety hazards, such as connectors being ejected due to internal pressure after air disconnection during traditional testing. Additionally, innovations focus on unique expansion component designs to achieve immediate sealing upon insertion, further improving installation efficiency and convenience.