Known by many names (quick couplers, quick release, quick connects, qds) the quick disconnect coupling is a useful tool to speed up the installation of hydraulic and pneumatic lines. A quick disconnect consists of a male and female half (nipple and coupler) which unite to form a complete coupling. Coupling halves are typically forged from metal and are composed of a body, latching mechanism, end-connection, and valving mechanism.
The most common material used is carbon steel, but brass and stainless steel are commonly used due to their corrosion resistant properties. Just as with hydraulic threads, each coupler is assigned a pressure rating which will vary depending on the material used, thread type, body sizes, and internal components. QDs are available in a wide variety of threads and sizes as well. NPT, JIC, ORB, and BSP are common, but metric threads, bulkhead threads, and hose barb connections are also available.
One of the most confusing aspects of QDs to newcomers is the difference between male and female halves. When working with hydraulics threads, we typically consider a male to have external threads and females to have internal threads. This is not the case with quick couplings. A male nipple may actually have female NPT threads, and a female coupler may have male NPT.
The gender of the threads does not determine the gender of the coupler. Instead, male couplers are male because a portion of their body is machined to fit within a female. Males are referred to as nipples or plugs. The female half is composed of retaining rings and components which accept the male stem, and typically have a retractable sleeve used to release the connection.
Before we get into coupling types it’s necessary to explain the internal components of a quick disconnect. In addition to the actual valve, couplings can contain seals, springs, sleeves, and bearings used to connect with the male and achieve certain performance functions. Differences in these internal components can completely change the way a coupler performs and connects with its counterpart.
Snap Type or Ball-Latching couplers use a spring-loading latching mechanism that accept a male nipple when pushed together. The male can be released by retracting a sleeve on the female. These couplers can typically be connected and disconnected with one hand.
If space constraints or safety are a factor, there are several QDs which may be attached without a ball-locking mechanism. Wing-Style, Chicago-Style, and Camlock couplers all use a non-latching mechanism. These couplers may connect via threads, locking-arms, or by simply pressing together and twisting. These connection types may be referred to as Bayonet Style, Screw-Type, or other various names.
In addition to these latching mechanisms, every QD has a unique shutoff style, determined by the valving mechanisms. These shutoff styles control how much, if any media is lost when the coupler disconnects. Depending on the media transported thought the coupler (gas, steam, hazardous chemicals) exposed media may present a health or safety concern, so it’s paramount that media stays within the coupling, and not all over your operators.
These couplers maintain the ease of connection while forgoing any internal valving mechanism. This grants these couplers a higher rate of flow, but does not prevent media loss when disconnected.
These couplers have a shutoff valve within one half of the coupling that prevents media from escaping when disconnected. Because the other half of the coupling does not have a shut-off feature, it’s important to take necessary safety precautions before disconnecting these couplers.
These couplers possess a shutoff valve in each half. This allows one to disconnect a coupler where residual pressure is present. These couplers will have minimum leakage when disconnecting as well.
These “no-spill” couplers are designed for a quick and spill-free connection, and typically used in applications where costly or hazardous materials are conveyed. These couplers are typically used in low-pressure industrial applications and often utilize a simple turn-and-twist connection method.
These couplers are designed for safety first and intended to prevent a spill if the coupling should suddenly become detached or if excessive pull is detected. One common application for these couplers is truck refueling, where accidentally driving away before the fuel line is detached could result in the spillage of fuel, downtime, and costly cleanup fees.
We’d be remiss if we didn’t mention the most popular sub-genre of coupling in our experience – the flat face coupling. These couplings rival traditional ball-latching style couplings but can connect and disconnect without media loss. Identifiable by the unique flat (or flush) face on both male and female halves, they connect by simply pushing together and twisting a sleeve. Intended for use in hydraulic and construction applications, these couplings also operate at very high pressures. Plus, the flush face system allows for easy cleaning between connections to avoid introducing contaminates into hydraulic systems.
No Tools Required. Connect QDs in the field with ease.
Protect your operators and avoid costly cleanup fees
Connect anything from hydraulic lines to pneumatic air lines with ease
Due to their versatility, quick disconnects can be used in virtually any application in tandem with hydraulic or pneumatic lines. We commonly see couplings used on agricultural equipment, air lines, pressure washing systems, hydraulic attachments, skid-steer manifolds, and truck and trailer applications.
If your system requires the constant connecting of lines, quick couplers offer a more convenient, safer alternative than reinstalling hose-end connections. This applies to in-field equipment, where tools are not always handy. And, certain threads such as NPT should never be used more than once. Failure to adhere could result in leaking end-connections or even catastrophic failure. Because quick couplings are designed to be used multiple times, you can prevent unnecessary leaks and speed up installation in the process!
If you’ve worked with hydraulic oil, transmission fluid, or a number of chemicals, you’d probably agree the last place you’d like to see that media is on the ground, or worse – over your operator or mechanic. Not only is this media potentially dangerous, buts it's often expensive as well. Leaks in hydraulic systems can lead to equipment performance issues and require excessive downtime to identify and fix the issue. Cleanup fees are also very costly and could result in fines in residential areas. Depending on your choice of QD, you can minimize spillage during line changes and avoid downtime.
If you think quick couplers are right for your application, don’t hesitate to reach out. Our team of experts can help identify your Faster, Safeway, Hansen, or other quick disconnect with ease. We can also recommend coupling types, materials, and configurations for your particular application. For more information on our QD offering, please take a look at our catalog here:
