Portability is another consideration. The cost differential will vary according to size and individual design. There are over a dozen common designs of quick-acting couplings. The company builds tools that will work with all types of push-lock fittings.Assembly tools can simplify the hose-fitting assembly process and there are several options to choose from, though we are not aware of any that are truly automated.
Quick couplers are designed to be connected and disconnected immediately without the use of tools, eliminating the need to close valves, bleed the system, recharge with fluid, and/or purge entrapped gas when parts are disconnected and replaced. Figure 1. Many of these calculations are based on flow of water at 60° F.Keep in mind that pressure drop for oil will be higher because of its higher viscosity. This practice not only minimizes fluid leakage, but also limits the amount of air, dirt, and water that can enter the system. One such products, P-80 Emulsion from Dixon, provides a thin film of lubrication that significantly reduce frictions when assembling rubber or soft plastic parts. I agree to receive commercial messages from IEEE GlobalSpec including product announcements and event invitations, Once the plug is in place, releasing the sleeve forces the balls inward against a locking groove on the OD of the plug. So if the hydraulic system cannot tolerate air inclusion, special provisions may be necessary to exclude air. These questions focus not only on the coupling, but the fluid medium as well. Therefore, check with the manufacturer to determine if the coupling will tolerate these conditions.The various designs of quick-acting couplings available differ not only in how the two halves connect to each other, but also in the valve arrangement to prevent fluid from escaping while the coupling is disconnected. Pneumatic systems generally employ this setup: the valved coupling half prevents air loss from the system while the joint is disconnected, the unvalved coupling half allowed downstream air to bleed off.In hydraulic applications, both coupling halves often are valved. A rule of thumb for air to estimate maximum air flow at 100 psig inlet and 5-psi pressure drop is to multiply flow coefficient of the coupling by 25. All have two parts: a plug and a socket. Will the coupling or hose be subjected to abuse such as impact from falling objects, severe vibration, or contamination from the environment?Once these questions have been answered, a preliminary selection of coupling type can be made: one, two, or no shutoff valves, and the type of connect/disconnect mechanism. If you are working with some of the specialized fittings mentioned earlier, it is important to select an assembly tool that easily adapts to them.When making or repairing hoses for any purpose, do not mix fitting and hose styles. The couplings may match based on nominal size but they may not mate or operate properly together.These pneumatic and hydraulic fittings are durable and reliable, but can be difficult to install.© 2020 Endeavor Business Media, LLC. Putting enough force on the hose without it buckling can be challenging, especially when not using a tool to assemble it. There are an assortment of different connection types available for attachment to a variety of systems and vessel types.In specific applications, quick couplings may be required to connect to a flange at one end of the adapter. and banjo fittings (which lack a surface to push against) can be a challenge. How often will the coupling be connected and disconnected? Although simple in concept, many quick-acting couplings are precisely engineered for specific fluid applications. But all hoses have an internal braid or mesh to give it strength. Without the couplings, separate air lines would be needed for each tool; the mass of tools and lines would clutter the workstation and could slow down production.On hydraulic test stands, quick-acting couplings eliminate bottlenecks by slashing the time required to test each assembly. To prevent these problems from occurring, select a coupling with a pressure rating substantially higher than the anticipated maximum operating pressure.Depending on the application, the coupling may be subjected to vibration or relative rotation between the mating halves while pressurized.