mono-couplings

Mono-couplings in many different designs

The various quick coupling types differ according to the intended application, the medium supplied though the line, the pressure conditions in the line and the connection mechanism. In terms of the intended application, there are thru-type couplings and adapters that ensure the free passage of a medium without a valve; however, the lines are not blocked when disconnected. Quick couplings and adapters with valves seal lines when disconnected; clean-break couplings and adapters additionally ensure drip-free disconnection with dry or low-leakage valves. Depending on the area of application, air, gas, acid, water or oil (e.g. for water and oil-based hydraulics) are used. According to the pressure conditions, there are low-pressure, medium-pressure and high-pressure quick connect couplings; depending on the connection mechanism, plug-type and screw-type couplings are used in industrial environments.

Low-pressure quick couplings

Standard low-pressure couplings are – depending on the type – designed for an operating pressure of up to 100 bar and are suitable for various media, including water, oils, fuel or compressed air. They are used, for example, on compressed-air consumers in tools and blow guns, or in the steel industry to supply equipment with hydraulics and compressed air. Depending on the application area, there are low-pressure couplings with an automatic locking mechanism that provides more convenience during coupling.

Medium-pressure quick couplings

Medium-pressure couplings, which – depending on the type – are designed for an operating pressure of up to 250 bar, are suitable for liquid and gaseous media. Clean-break couplings in the medium-pressure range are used for hydraulic applications, for example, but are also suitable for connecting lines that supply compressed air, water or fuel. Depending on the application area and equipment, mono-couplings have an automatic locking mechanism or unlocking protection.

High-pressure quick couplings

Quick couplings can also withstand high pressures. High-pressure couplings – depending on the type –are suitable for an operating pressure of up to 2,000 bar and are used, for example, for pneumatic oil lubrication on roll stands in the steel industry. In order to withstand this type of extreme stress, mono-couplings for high-pressure applications have a very robust design. This also applies for applications in offshore installations where quick-connect couplings are often required to operate under seawater applications for decades.

To prevent leaks and environmental pollution, couplings with special sealing systems are required here. These include quick couplings for hydraulic control and chemical injection systems, but also mono-couplings for gas lines that can be operated by a diving robot, a so-called “remotely operated vehicle” (ROV).

Clean break couplings

In sensitive sectors such as the chemical and pharmaceuticals industry, where the safety standards are particularly high, clean break couplings ensure drip-free connection and disconnection of lines; for example, for taking samples of various liquids and gases. Clean break valves ensure that connection is possible without splashes, air inclusion or media loss, and – depending on the valve – even under residual pressure.

Plug- and screw-type couplings

In the medical technology industry, plug- and screw-type couplings are used for quickly connecting and disconnecting lines, whether they are clean-break couplings for coolant lines in computer tomographs, quick couplings in dialysis machines or self-sealing couplings for supplying medical gas in hospitals. To ensure safe operation and prevent incorrect line connections, the couplings are available in different colour markings and/or mechanical coding versions to make them non-interchangeable.

Function and advantages of quick-connect couplings

Using quick-connect couplings provides more flexibility and a greater economic benefit, as lines can be disconnected and re-connected quickly and safely. On vehicles, for example, mono-couplings facilitate the assembly and maintenance of heating and air-conditioning systems, or they enable safe refuelling with gaseous hydrogen. On rail vehicles, the couplings are a key component of hydraulic and pneumatic brake systems, energy supply systems or air conditioning systems.