What is a pneumatic quick-connect fitting? A complete analysis of its structure, principle and core performance

1. Definition and classification of pneumatic quick-connect fittings

Basic definition

Pneumatic quick-connect fittings are a device that achieves quick connection of air pipes through a mechanical locking mechanism. Its features include:

No tools required: connection/disconnection can be completed with one hand

Instant sealing: built-in O-ring or cone sealing structure to prevent gas leakage

Reusable: supports frequent plugging and unplugging (usually >10,000 times)

Main classification

According to function and structure, it can be divided into the following types:

2. Structural principle and working process

Core components and functions

The typical structure of pneumatic quick-insert fittings includes the following components:

Clamping mechanism: stainless steel beads or spring claws, used to lock the air pipe (radial clamping force is usually >50N)

Sealing element: nitrile rubber (NBR) or fluororubber (FKM) O-ring, with a pressure resistance of up to 1MPa

Valve body assembly: spring-driven valve, which automatically closes the pipeline when disconnected

Shell material: PBT (chemical corrosion resistance), brass (high strength) or stainless steel (high temperature resistance)

Workflow (taking the two-end opening and closing type as an example)

Insertion stage:

The trachea pushes the ferrule to compress the spring, and the steel ball rolls outward to make way

The trachea pushes the sealing ring and pushes the valve to form an airflow path

Locking stage:

The ferrule is reset under the action of the spring, and the steel ball is stuck into the groove of the trachea to achieve mechanical fixation

The O-ring fits tightly with the outer wall of the trachea to form a seal

Disconnection stage:

Pull the ferrule backward, the steel ball is separated from the trachea, and the valve is automatically closed under the spring force

3. What should you pay attention to when using pneumatic push-in fittings?

Installation and connection specifications

• Air pipe pretreatment

Cutting requirements:

Use a special pipe cutter to ensure a smooth cut (inclination <3°)

Remove burrs (to prevent scratching the O-ring)

Cleaning steps:

Wipe the inner wall of the air pipe with lint-free cloth dipped in alcohol to prevent particles from entering the air path

• Correct connection method

Key points for operation and maintenance

• Daily inspection items

Leak detection: Apply soapy water to the interface every week and observe bubbles (minor leaks require timely replacement of O-rings)

Trachea status: Check the trachea for cracks and hardening every month (aging trachea needs to be replaced immediately)

• Regular maintenance

• Prohibited operations and risk warnings

Prohibited behaviors

Use overpressure (exceeding the rated pressure will cause explosion)

Mixed media (such as oxygen joints mistakenly connected to grease pipelines causing explosions)

Plug and unplug under pressure (pressure must be released before operation to prevent airflow impact and injury)