New Connectors Ease Hydraulic Assembly

June 5, 2008
Push-to-connect fittings install fast and help prevent leaks.

Edited by Kenneth Korane

Manifolds, valve blocks, and other components with multiple ports often force designers to cram fittings into tight spaces, so installation becomes slow and laborious. And threaded fluid connectors pose the danger of over or under-torquing, or cross-threading, which quickly leads to failure and costly rework.

To streamline production, several manufacturers have introduced connectors that speed assembly and help ensure leak-free connections. Parker Hannifin’s Fluid Connector Group, headquartered in Cleveland, has launched the Universal Push-to-Connect (UPTC) assembly that reportedly reduces assembly time by as much as 90% on industrial and mobile equipment. Design of the UPTC involved collaboration between Parker’s Tube Fittings, Hose Products, and Parflex Divisions.

The UPTC consists of a base Seal-Lok O-ring face seal (ORFS) or EO metric bite-type fitting, a nut attached to the fitting that houses internal sealing and retaining elements, a dust-protection O-ring, and a hose or rigid-tube assembly. Users simply push the hose or tube into the nut to make a hydraulic connection — no tools are needed. Visual and tactile indicators on the nut and fitting signify full engagement that holds up even under vibration and high pressure.

Mechanics can disconnect the assembly using a wrench to loosen the nut, exposing a standard connector end. This is a major difference from many other push-to-connect fittings which rely on special tools and proprietary fittings, says David Weis, a Parker product manager. “The fact is at some point the hose will fail, and the assembly will need to be replaced,” says Weis. “Customers can go to any hose-fabrication shop and get a standard ORFS hose assembly,” he says, rather than relying on nonstandard components that are often tough to locate and typically add to cost and downtime.

UPTCs are suitable for rigid inch and metric tubing, and hydraulic and thermoplastic hose assemblies involving tube-hose, tube-port, and hose-port connections. And the standard design makes possible a virtually unlimited variety of connection configurations, says Weis. Additional information is available at

Gates Corp., Denver, has introduced Quick-Lok, a series of threadless couplings that also need no tools for assembly. They simply push-on with little force to make hydraulic connections. The couplings are said to eliminate leaks and substantially increase assembly- line productivity.

Two different configurations are designed for hydraulic equipment that uses one and two-wire, standard SAE 100R1 and 100R2 hoses. The Quick-Lok High connection consists of a hose stem and adapter and works at pressures to 5,000 psi (350 bar). The second type, Quick- Lok Direct, is a releasable connection for direct-to-port applications that eliminates the need for an adapter. It also handles 5,000-psi working pressures.

Quick-Lok results in torque-free connections. Thus, they prevent hoses from twisting during assembly, a main reason for premature hose failure. The couplings can be removed from the port with a standard wrench but cannot be unintentionally disconnected, an inherent safety feature. And they handle impulse and side loads, flexing, vibration, temperature extremes, and vacuum. For additional information, visit

Eaton Corp.’s Fluid Power Group recently introduced a next-generation connector that builds on more than a decade of experience in push-to-connect designs. The device, called STC EZ Torque, is compatible with standard threaded ports and can be installed without an adapter. According to company officials, it eliminates the need for special ports and tools. STC EZ Torques make connections without the need for an integrated receiving port (direct port) or adapter, and suit both mobile and stationary applications.

Users simply push the connector into a standard component port, rotate it to the required orientation, and tighten a hex to secure. The fitting unscrews to disconnect.

The STC coupling is said to combine the advantages of threaded and threadless connectors, providing efficient assembly, the ability to orient routing angles, and handle high pressure and extreme vibration. Compatible port types include O-ring boss (SAE J1926), O-ring (ISO 6149), BSPP flat face (ISO 1179), and metric form E (ISO 9974). Sizes range from 0.375 to 1.0 in. with pressure ratings to 345 bar (5,000 psi). More details can be found at

Quick-Lok push-to-connect fittings from Gates prevent hoses from twisting during assembly, which is a leading cause of premature hose failure

UPTC components from Parker Hannifin are available in straights, 45 and 90° elbows, tees, and crosses in 0.25 to 1.0-in. ORFS fittings and 8 to 25-mm metric bite-type fittings. They connect to most standard ports, including SAE J1926 straight thread, ISO 6149, and pipe connections.

Eaton’s STC EZ Torque connectors push into a standard port and are then tightened to secure.

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