Fluid Gas Handling

Not All O-ring Face Seal Fittings Are Created Equal

Not All O-ring Face Seal Fittings Are Created Equal  -Parker's Seal-Lok ORFS fittings and adapters have exclusive enhancements that ensure the most leak-free connection on the market.
Stretch your mind back to the early 1980s… the first analog cell phone was released by Motorola measuring roughly 12 inches long, personal media players were bulky, playing only cassettes or CDs, and WordStar was launched as the first word processing program. In the world of fluid and gas handling, the 80s were also a time of new development. The O-ring face seal (ORFS) fitting for industrial hydraulic applications was introduced in an effort to eliminate leakage commonly seen in hydraulic systems experiencing higher operating pressures and more severe mechanical shocks. Named for its key design feature, the ORFS fitting utilizes an O-ring that provides a more reliable seal than traditional metal-to-metal tube fitting styles.  

Why go with an O-ring?

Over the nearly 40 years since its release, the ORFS fitting has built a reputation for delivering a variety of important benefits. In addition to providing a more reliable connection seal, this fitting design offers:
  • Zero clearance for easy plumbing

  • Resistance to over-torquing/eliminated damage from over-tightening

  • Vibration resistance/reduced loosening caused by system vibration

  • Flat face and elastomeric seal for unlimited reusability

However, as the title of this post implies, there are many ORFS fittings in the market. All ORFS fittings improve reliability over metal-to-metal fitting styles – no doubt – but Parker has spent decades developing exclusive enhancements to our Seal-Lok™ ORFS fittings that eliminate potential issues and extend the fitting’s capabilities. 

Trap-Seal solves the common issues

Parker Trap-Seal™ technology proactively protects against issues that some people experience when using ORFS fittings: O-ring fallout and O-ring pinch. Parker's Trap-Seal, the trapezoidal-shaped seal, eliminates O-ring fallout and pinch that happen with ORFS fittings.
O-ring fallout: This can happen during transit, storage or assembly. When an ORFS fitting is assembled without an O-ring, the key sealing mechanism, the connection will leak. Sometimes the missing O-ring is caught, but not always. Either way, it adds to the time needed to assemble (or reassemble!) your connection. 
O-ring pinch: Caused when an O-ring partially pops out of the groove and is pinched outside of the groove during assembly, O-ring pinch compromises the connection seal and can cause leaks.
To eliminate these potential issues, Parker developed Trap-Seal™, a trapezoidal-shaped seal that sits snugly in the ORFS fitting’s captive O-ring groove (CORG). It ensures improved retention and provides maximum assurance for leak-free connections.

The more robust, the more reliable 

Parker's Robust Port Stud on adjustable SAE boss port ends has a longer locknut to eliminate the O-ring pinch issues commonly seen.The O-ring pinch issue can happen on adjustable SAE O-ring boss (ORB) port ends as well. This is due to thread exposure below the locknut that leads to a deformed backup washer, pinching the O-ring and creating an O-ring extrusion gap with the potential to leak. To fix this, Parker created the patented Robust Port Stud™. With a longer locknut, the Robust Port Stud eliminates exposed threads and the leak potential of adjustable SAE O-ring boss port ends. This enhanced port end comes standard on all Seal-Lok fittings with an adjustable SAE O-ring boss port end.  


Tough applications call for tough measures

As you know, ORFS fittings were developed for high-pressure applications. Many of these are also in harsh environments where corrosion is a constant threat to equipment life. When sourcing ORFS fittings, corrosion resistance should be on your radar. Parker offers ToughShield plating, which comes standard on our steel Seal-Lok ORFS fittings, and provides up to 1,000 hours of corrosion resistance – more than 10 times the SAE required standard - and outlasts the competition. See the results for yourself.
                        Parker's industry-leading ToughShield plating comes standard on all tube fittings and adapters.

Seal-Lok ORFS tackles new markets and applications

Parker has taken the many advantages of the ORFS fitting design and engineered versions to perform in applications with unique demands where other ORFS fittings on the market cannot. Understanding these differences will go a long way in optimizing your operation. Here are a couple of new Seal-Lok variations currently available:

Parker's Seal-Lok for CNG utilizes a HBNR compound o-ring making it perfect for both infrastructure and on-vehicle applications.
Seal-Lok for CNG: Utilizing an elastomeric seal compound specially designed to address the needs of the natural gas market, this ORFS fitting improves ozone resistance and supports wider temperature range requirements (-40° to 300° F). Seal-Lok for CNG has been tested and certified by TUV according to the ECE R110, ANSI NGV 3.1-2014/CSA 12.3-2014 standard for stainless and zinc-nickel plated fittings, as well as ISO 15500. It also passed Bonfire Testing in accordance with ANSI/CSA NGV 2. Seal-Lok for CNG is improving connection reliability in CNG applications for on-vehicle fuel systems and on infrastructure applications such as compressors, dryers, fuel dispensers and storage tanks.
Parker's Seal-Lok Xtreme has a patented metal seal that expands ORFS fittings' temperature and chemical capability.Seal-Lok Xtreme: This ORFS fitting utilizes a patented metal seal that expands the fitting’s temperature and chemical capability. It achieves superior tube and hose connections at temperatures as low as -328°F and as high as 1200°F. It’s also available with a patented metal port seal on fittings with the SAE J1926 O-ring boss port end. Seal-Lok Xtreme has been extensively tested in the areas of thermal cycle and shock, as well as shown success in helium mass spectrometer and pressure testing. All of this makes it a good fit for applications like combustion turbines, LNG storage and fueling systems, high-temperature engine compartments, instrument panels, and cryogenic equipment.

Innovation makes all the difference

Things have come a long way since the ’80s -- cell phones are now mini personal computers and media players that fit in your pocket, music is digital, leaving cassettes and CD’s a thing of the past, and word processor programs have vastly improved. Parker’s Seal-Lok ORFS fittings have also come a long way since the ’80s. Though the original ORFS design is still superior to many other connection types today, with the many exclusive enhancements made by Parker, only the Seal-Lok ORFS fitting has been able to take this reliable leak-free connection design to the next level much like some of the other technology improvements noted. At Parker, we’re always innovating and making sure that we provide our customers with the best possible solutions to optimize both their operations and bottom line. 
Refer to our Tube Fittings Division Frequently Asked Questions page, www.parker.com/tfd-faq, for a wealth of information and resources. 
Seal-Lok O-ring Face Seal Fittings are now available for purchase on Parker.com.  Simply add products to your cart for shipment within two days for in-stock items.
Looking for technical support and information? Subscribe to TFD techConnect posts by email. TFD techConnect is a technically-focused monthly blog written by engineers for engineers specifically around motion and control engineering challenges.
Wendy Davison-Moore, marketing services manager at Parker Tube Fittings Division
Contributed by Wendy Davison-Moore, marketing services manager at Parker Tube Fittings Division and 
Cody Yarletts, product sales manager, Parker Tube Fittings Division
Cody Yarletts, product sales manager at Parker Tube Fittings Division
Additional related content about hydraulic tube, hose, and port fitting connections:

Have a question about Parker products or services? We can help: Contact Us!

Comments for Not All O-ring Face Seal Fittings Are Created Equal

Please note that, in an effort to combat spam, comments with hyperlinks will not be published.

Leave a comment