Quick Disconnect Couplings

About Quick Disconnect Couplings and Quick Disconnect Coupling Manufacturers Including: Hydraulic Quick Disconnects, Quick Connect Couplings, Quick Coupling, Quick Disconnects & Quick Release Couplings.

Quick disconnect couplings are simple mechanical devices used to join and detach two sections of hosing or piping. Quick disconnect coupling manufacturers offer quick and easy connect/disconnect products for convenience purposes. A coupling consists of two mating parts. The first is the male nipple, which is an elongated tip. The male half is inserted into the female body, which is most frequently a small metal piece with a circular opening. Quick disconnect couplings are relatively maintenance-free and are often able to be connected or disconnected with only one hand.

Quick disconnect couplings and fittings, though used in similar applications, have major differences. Fittings do not have shut off valves, while these valves are built into the couplings. A coupling can rotate while it is connected, but a fitting cannot. Under side-load, fittings will leak; couplings will not. Quick disconnect coupling manufacturers design products that can undergo up to 2,500 cycles with no leakage, while tubing must be re-cut after every use of a fitting. There are no standard fittings; different materials require different fittings. However, couplings are able to work with all types of tubing.

The majority of quick disconnect couplings are composed of a type of metal, such as stainless steel, steel or aluminum. Chrome-plated brass quick disconnect couplings are ideal for higher pressure and temperatures in such applications as pneumatic air supply, instrumentation and cooling or high temperature lines. Plastic couplings have grown in popularity due mostly to their corrosive-resistant properties and lower cost. Polypropylene (PP) is a lightweight, gamma sterilizable, chemically resistant thermoplastic that can replace heavier stainless steel or brass couplings in applications, such as photo processing, caustic fluid and gas transfer and medical disposables. Polysulfane provides superior strength and good chemical resistance and can withstand repeated sterilization. This material is perfect for strong oxidants and hot or cold liquids in potable water systems and medical applications requiring autoclaving.

Choosing the appropriate quick disconnect coupling depends on the factors within the application. Quick disconnect coupling manufacturers can help in knowing the minimum and maximum temperature and the maximum pressure the coupling will need to withstand. Consider the chemical compatibility of the coupling material, whether or not it will be able to handle the viscosity and corrosiveness of the media. Are automatic or integral shut off valves required? Calculate the gallons per minute (GPM) and pressure drop, taking into consideration the effects of the shut off valves and tubing connections. Note both the inner and outer diameters of the tubing. Common tubing connections include hose barb, compression fittings and push-to-connect termination styles. Pipe thread, panel mount, in-line or elbow are some mounting choices. Take into consideration any special requirements, such as sterilization, color coding, special packaging, etc. Overall, the three most important elements to focus on when choosing quick disconnect couplings are as follows: ease of installation, replacement and serviceability.

Types of Quick Disconnect Couplings

• Air conditioner couplings are used in refrigeration and cooling system applications. Air conditioner couplings are designed to withstand vibrations without disconnecting and to minimize any refrigerant leakage once disconnected.
  
• Ball connectors have a number of balls on one or both of the male/female bodies that are drawn in when a button is pressed. Once the balls are drawn in, the two halves are connected and the button is released, projecting the balls and locking them in place.
  
• Connect-under-pressure couplings use a valve to relieve backpressure. This design makes it simpler to insert the hose into a receiver when hydraulic lines must be connected or disconnected.
  
• Double shut-off quick-release couplings have shut-off valves in both the male and female halves.
  
• Dry disconnect couplings are used at liquid transfer points to prevent excess spillage and to decrease the hazards typically found when handling/processing corrosive, toxic, caustic or other harmful products. Dry disconnect couplings are ideal for applications in which VOCs (Volatile Organic Compounds), that have a high vapor pressure and evaporate quickly, are present, as they keep the product in-line and out of the ambient environment.
  
• Drybreak couplings are sliding, sleeve-style, quick disconnect couplings for hydraulic systems. Drybreak couplings are capable of connecting with little air inclusion and can be disconnected with minimal or no spillage.
  
• High flow couplings are used in application in which larger volume flow is required. High flow couplings can be made of polypropylene (PP), polysulfone, brass and stainless steel, among other materials.
  
• Hydraulic quick disconnects are any type of quick disconnect that is used in a liquid system. Hydraulic couplings commonly contain shut off valves to prevent spillage and reduce air inclusion when connecting/disconnecting.
  
• Non spill couplings are resistant to a wide range of media. Standard nonspill couplings come with non-spill shut-off valves, color-coding that delineates a variety of media lines, olefinic overmolding, which makes the connection more durable and improves the grip for users and seals, and springs formed from materials that are determined by the amount of chemical resistance required.
  
• Non-valved quick-action couplings do not have shut off valves in either the male or female halves.
  
• Pneumatic couplings, also called “single shut off (SSO) couplings,” are generally used to connect tools, equipment and hoses that utilize compressed air. Pneumatic couplings may also be used in applications in which other gases and low pressure liquids are in use.
  
• Poppet couplings are a type of valve used in hydraulic quick disconnects that disables fluid flow when the two mating halves are separated. The poppet-style quick disconnect coupling is one of the most popular hydraulic couplings.
  
• Push-and-pull quick disconnect couplings typically have a sleeve on the female half that is pulled back and into which a male tip is inserted, locking it into place when the sleeve is released. To disconnect, the sleeve is once again pulled back, and the male half is withdrawn.
  
• Quick action couplings are often used to separate or join hydraulic lines. The quick action coupling eliminates the need for tools or special devices.
  
• Quick connect couplings are used to join pipes and prevent leakage.
  
• Quick couplings are composed of a male plug and a female coupling and are used to join pipes and hoses.
  
• Quick disconnects are plugs used to connect pipes and hoses quickly, in order to prevent leakage or a drop in pressure.
  
• Quick-release couplings form watertight connections between corrugated hoses, pumps, filters, etc. that can be easily disconnected and reconnected without the use of tools. Quick release couplings are simple to align and can withstand a wide range of water pressures.
  
• Single shut off quick-action couplings have a shut off valve in either the female or male half only.
  
• Threaded couplings are best suited for high pressure and high flow applications. To form a connection, the male half of a threaded coupling is screwed into the female acceptor, both of which are threaded, and turned clockwise; the male half is turned counterclockwise to disconnect the coupling.

Quick Disconnect Couplings Terms

Air Inclusion – Ambient air that is forced into a system during the connection of quick disconnect coupling mates.

Brinelling – Grooves or dimples that are worn into the shoulder of a male half. These deformations are engendered by the locking balls of a female body.

Break-Away Clamp – A device that clamps to hold the sleeve of the quick disconnect coupling, which permits movement of the body. The movement is either forward within a single- or double-acting sleeve upon disconnect, or backward within a double-acting sleeve upon connection.

Connector – Any device that is used to join two or more parts together. In quick disconnect couplings, the male tip is often referred to as the connector.

Connect-Under-Pressure Rating – The designation given to a coupling that refers to its ability to be connected with applied pressure from one or both sides of the hosing.

Coupler – A part used to connect multiple pieces together. Female acceptors are referred to as couplers in quick disconnect couplings.

Double-Acting Sleeve – A sleeve that allows for pull-to-disconnect and push-to-connect.

Dust Cap – A removable device that protects the male tip from everything but contamination when it is disconnected from the female body.

Dust Plug – A removable device that protects the female body from everything but contamination when it is disconnected from the male nipple.

Female Body – The accepting half of the coupling. The female body consists of an opening that contains locking balls to keep the male end in place.

Flow Checking – Also called “ball checking,” “lock-up” or “check-off,” it is the closure of the male tip half valve during high flow conditions, such as the rapid lowering of a heavy loader.

Inside Diameter (ID) – The distance measured from an inner surface of a quick disconnect coupling to the innermost point directly opposite the original mark. Equal inside diameters between connectors and hosing ensure equivalent flow rates throughout the system.

Interchange – The variations in locking design between internal coupler mechanisms and external nose configurations.

Locking Balls – A series of small, circular-shaped objects that project and retract from a female body. Locking balls allow for the insertion and withdrawal of the male nipple.

Male Tip – The nipple-shaped coupling half. The male tip is inserted into a female body and kept in place by locking balls.

National Taper Pipe Thread (NPT) – A standardized groove design for threaded parts for the United States.

Pivot Joint – A connector assembly that is able to turn in multiple directions.

Poppet Valve – A machined, self-aligning valve that typically offers higher flow than ball valves. Elastomers are incorporated into poppet valves to provide a positive seal upon disconnect and to prevent low pressure leakage.

Pounds Per Square Inch (psi) – A unit of measure of pressure. The maximum rated psi for quick disconnect couplings must meet or surpass that of the other system components to ensure reliable performance.

Spillage – Fluid or air loss in a system due to the disconnection of a coupling device.