What are Quick Coupler or Quick-connect Coupling?

Author: CC

Jan. 29, 2023


Quick couplings are also known as quick connect couplers. These are general purpose couplings that can connect at either end of the connection.

Quick-connect couplings are connectors or fittings used to mate fluid lines with equipment that requires repeated connections and disconnections. They are used in both hydraulic and pneumatic applications, and are designed for easy hand operation for use with fitting attachments primarily on mobile machinery.

They are generally designed according to the maximum working pressure and could be made of steel, brass or stainless steel depending upon the application and the type of fluid.

Their design is simple: a male end—or plug—is inserted into a female end—or socket—to make a secure, leak-tight seal. They are sometimes called push-to-connect because connecting them requires only a quick push.

They usually feature a one-way sleeve to allow for break-away with a tool when a coupling is clamp mounted. Two-way sleeves allow for one-hand disconnection. In two-way designs, twisting and pulling the two ends breaks the connection.

The couplings basically have two parts mainly –  a socket and a plug.

What are Quick Coupler or Quick-connect Coupling?

Coupler Socket Construction:

Quick Coupler Socket Construction

Coupler Socket Construction Specifications:

Coupler Socket Construction Specifications

These locking seal quick-connect couplings are created by several designs, including:

Ball or bearing type, in which spring-loaded balls lodge in cavities to make the connection. This is the most common type, because they can be disconnected with just one hand.

Flat face designs eliminate the problems of trapped pressure in a line, as well as leakage of hydraulic fluid or air by eliminating the cavity where the fluid or air rests. They can be push-to-connect or threaded, screw-in types. Flat face couplings provide high flow and low pressure drop and their sleeve-locking feature reduces the change of accidental connection.

Non-latching designs are best used when there may be frequent change-outs of the coupling, such as pneumatic ones used in test or medical applications. They usually come with a self-sealing valve that will hold the fluid in the line to prevent any leakage.

Bayonet couplings are simple to connect. The user plugs the two ends together and once engaged, gives the devices a quarter-turn to push the male end into the female socket. Twisting them a quarter turn the other direction allows them to be easily disengaged and separated. Although used in high-pressure hydraulics, they are more common in pneumatic applications.

How to Identify Coupler Plug Designs

The Standard Sleeve Type Couplers and Plugs are manufacture to insure

interchangeability with other manufactures coupler and plugs.the following standard interchanges are avaiable:industrial interchange(Hansen) series,Automotive(Tru-Flate) series,Lincoln series,and the Straight Through(No Valve) series.


This type of plug has the shortest tip compared to the other three types of plugs.It has the widest section between the ball groove and the tip.

This design has a thick sealing surface around the tip,which provides better sealing and longer seal life.

Very short tip / Thick sealing surface / Wide section

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This type of plug has been adopted by all major manufacturers.The couplings that will mate with this plug are either“sleeve”type or “push”type couplings.To identify this plug,look for the 3/16”tip and a V shape,flat bottom ball groove.Complies to ANSI T 3.20.14 dimensions.

3/16”tip / V shape,flat bottom / ball groove

ARO - ARO Type

To identify this plug,start from the tip.It has a 5/16”tip and around ball groove similar to the A/T type

5/16"tip / Roundball groove

LincoIn Type - L STYLE

This is the most easily identified plug due to its long tip.The tip length is 3/4”and can only be used with a matching coupling design.

3/4"tip / Round bottom ball groove

How to Identify Coupler Plug Designs

Quick Coupler & Plugs

Quick Coupler & Plugs

Quick Couplers & Plugs Introduction

quick coupler & plug introduction

Quick disconnect couplers are the fastest,easiest,and most reliable means of joining pneumatic and fluid transfer lines.

All quick disconnect couplers work on the same principle:

Hardened balls or pins engage a groove in the coupler plug to hold it securely against a soft sealwhie permitting to swivel,thereby preventing kinking or twisting of hose.

A sliding sleeve releases the locking balls when retracted,permitting the plug to be inserted or removed.The sleeve automatically returns to the locked position when released.

An automatic shutoff valve in the coupler seals instantly upon uncouplig,eliminating the need for a separate shutoff.

Air Quick Coupler Features/Benefits

Long Service Life. Zinc plating provides an on-corrosive finish.Heat treating hardens critical wear points.Molded Buna-n seals create a leak proof connection.

Efficient Performance. Tubular valve design provides high flow rates.Steel locking balls ensure connection holds tight under the most rugged applications.Spring loaded sliding outer sleeve allows quick connec/disconnect

Many Sizes&Styles. Available in 1/4,3/8,1/2,3/4 inch bodies with male and female pipe threads,hose barb or lock-on ends for every application.

Interchangeability. Fully interchangeable with couplers and plugs made by other manufacturers.(See interchange chart) .

quick coupler identification chart

You may be interested in our range of Longwei Air Fittings including adaptors, quick coupler connectors, tire gauges, air blow gun, air chuck and tire repair tools kit, etc. If you have any further questions about the type of thread fitting you require, please contact the Longwei team today!

Related Products:

Air Truck with Pressure Gauge

Brass Quick Connect Fitting

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