What is a Hydraulic Quick Coupling?
Modern hydraulic machinery often performs multiple tasks and requires frequent attachment changes. Quick couplings support these tool changes by maintaining hydraulic power, reducing pressure drop, limiting oil spillage and enabling low-effort connection. This makes them an essential component for construction, agriculture and other equipment operating with auxiliary hydraulic lines.
Why Quick Couplings Matter in Hydraulics?
Quick couplings matter in hydraulics because they provide quality and performance across general hydraulic applications. The Q.Safe range is composed of more than 1,200 references, accessories and spare parts. It assures total interchangeability with other quick coupling products on the market. The majority of the product range offers excellent resistance to corrosion with Cr3 plus and Zinc Nickel coatings that exceed ISO 4520 requirements.
Q.Safe Flat Face Program
The Q.Safe Flat Face Program is a core part of the Manuli product range. It was developed to extend what can be achieved with high-performance production couplings. The program is comprised of four flat face valve models, each designed to Manuli’s high specifications to suit demanding applications.
The Q.Safe Flat Face Program includes:
- MQS-F – Flat FAce Couplings
- MQS-FH – High Pressure Flat Face Couplings
- MQS-FP – Flat Face Coupling with Male Connectable Under Pressure
- MQS-FS – Screw Type Flat Face Couplings
MQS F: Flat Face Couplings
The MQS-F flat face coupling provides global interchangeability, high pressure capability, and a low pressure drop profile to support efficient hydraulic performance. Its streamlined internal design supports high flow rates, while the Cr3+ trivalent chrome coating delivers more than 400 hours resistance to red rust under salt spray conditions.
The coupling supports connection with the female half under residual pressure up to 6 MPa and operates at working pressures up to 25 MPa when disconnected and 35 MPa when connected. It performs reliably across temperatures from −30°C to +110°C. A moulded polyurethane seal, selectively tempered high strength materials, and ISO 16028 interchangeability contribute to durability, with endurance testing to 1,000,000 cycles at 120 percent working pressure. Oil spillage during connection and disconnection remains minimal, supporting cleaner operation and reduced contamination risk.
MQS FH: High Pressure Flat Face Couplings
The MQS-FH series is designed for continuous service in high-pressure applications. Compared with the standard MQS-F series, MQS-FH couplings have a more robust outer structure and higher resistance internal components to support demanding hydraulic conditions.
MQS-FH also offers increased service life in heavy-duty applications and improved corrosion resistance through a Zinc Nickel (ZnNi) coating that provides up to three times longer corrosion resistance. The series is connectable with female under residual pressure up to 6 MPa and supports a working pressure of 35 MPa in both connected and disconnected states. Design features include an enhanced polyurethane (PU) seal, more robust construction and improved energy efficiency.
MQS FP: Connect Under Pressure Flat Face Coupling
MQS-FP is often used on earth-moving machine implements and can be connected and disconnected with the male coupling under full working pressure. This is achieved through the addition of a micro valve with a mini polyurethane seal, forming a triple valve system that enables operation under pressure.
In addition to the standard MQS-F properties, the MQS-FP series offers connection at a full working pressure of 35 MPa when the male coupling is pressurised, with Zinc Nickel plating for enhanced corrosion resistance. MQS-FP supports a working pressure of 35 MPa in both connected and disconnected conditions and maintains low connection effort during pressurised coupling.
MQS FS: Screw Type Flat Face Coupling
MQS-FS incorporates design features from the rest of the flat face series and is considered the quintessential coupling of its type. Ruggedly built and maintaining the hydrodynamic performance of the broader Q.Safe flat face range, MQS-FS is suitable for demanding and severe applications.
In addition to the properties of the standard MQS-F series, MQS-FS can be connected with both couplings at a full working pressure of 35 MPa and supports working pressures up to 42 MPa when connected and up to 35 MPa when disconnected. The series features Zinc Nickel corrosion resistance up to 720 hours, screw coupling for minimal connection effort under pressurised conditions, an improved moulded polyurethane seal and extremely robust construction.
Flat Face Multiconnectors
The Q.Safe Flat Face Multiconnector range combines the performance of Q.Safe flat face couplings with the efficiency and safety benefits of a multiconnector block system. The range is designed to reduce connection time when multiple connectors are used, with no risk of incorrect connection and no misalignment between mobile and static blocks. The compact design supports minimal added weight and allows hoses to be arranged closely while still permitting easy access.
Flat face couplings within the system support high pressures (350 bar) and high flow rates, offering industry leading performance with reduced pressure drop. Oil wastage during connection and disconnection is almost zero (between 0.007 cc and 0.009 cc) and connections can be made under residual pressure. The system is also easy to clean and easy to maintain, supporting reliable operation in applications where multiple couplings are used.
MQS-F: 90° Flat Face Quick Couplings
MQS-F 90° quick couplings provide a solution for applications where space is restricted, or a straight coupling is unsuitable. They are especially useful on vehicles and equipment that use multiple tools, where hose routing requirements can prevent the use of standard straight quick couplings. By changing the orientation of the hose connection, the 90° design allows more efficient packaging of hydraulic hoses and components.
The 90° configuration introduces a degree of internal turbulence which increases pressure drop across the coupling. Designed to the same standards as the MQS-F quick coupling series, the 90° version maintains minimal additional pressure drop and remains one of the most efficient couplings of its type. Available in sizes 3/8″ and 1/2″, MQS-F 90° quick couplings are designed in accordance with ISO 16028, making them fully interchangeable with other flat face coupling brands.
MQS-ARM & MQS-ARB
MQS-ARM and MQS-ARB are advanced non-flat face couplings designed for rigid mounting on agricultural vehicles. Compatible with standard ISO A male couplings, these products support demanding operating conditions where connection under pressure and reliable performance are required.
MQS-ARM supports residual pressure connection with the male coupling under pressure and uses a push pull connection format with automatic disconnection in line with ISO 5675. The series supports working pressures up to 30 MPa, has a safety factor of 4:1 for dynamic pressures, and is endurance tested to 500,000 cycles at 120 percent of working pressure.
MQS-ARB provides additional functionality by allowing connection under full pressure, enabling both couplings to be connected under pressure. This supports greater operational flexibility in agricultural applications.
Direct to Hose Integration (DHI)
The Q.Safe DHI program allows the quick coupling to be assembled directly to the hose, removing the need for typical adaptor fittings. By integrating the coupling with the hose assembly, DHI reduces the number of components and simplifies fit-out across common hydraulic applications.
Direct installation supports fewer assembly parts, improved leak prevention and easier maintenance. Field use is aided by reduced unscrewing issues and compatibility with ISO A, ISO B and flat face series. The approach maintains safety by reducing assembly errors and provides a cost-effective maintenance path without the need to replace the hose.
H2 MQS-FEH: Impulse Solutions for Heavy Duty Applications
The MQS-FEH series is engineered for extreme high-frequency impulse conditions at high pressures, supporting reliable service in demanding machinery and off-highway equipment. A unique locking system (patent pending) and reinforced coupling design allow the series to deliver a long lasting, leak free seal in applications that produce heavy vibration and shock loading. Potential failure modes associated with high impulse applications have been addressed through the updated design, supporting dependable performance in the field.
MQS-FEH couplings suit a wide range of machinery and tools including hydraulic hammers, stone crushers and screeners, demolition equipment, vibratory compactors and road rollers, asphalt milling equipment, pile driving equipment, hard rock drilling equipment and general off-highway machinery subject to high levels of vibration.
Overall, the Q.Safe range delivers high quality quick coupling solutions designed to meet the performance, safety and durability requirements of hydraulic applications.