Parker D.O.T. Fittings: Compression vs. Push-to-Connect

Posted by Marek Bobik on Tue, Jun 28, 2011 @ 05:58 PM
Marek Bobik
Parker push-to-connect transportation fittingIn most transportation applications there are clear advantages to using D.O.T. approved push-to-connect fittings over compression fittings.

While push-to-connect fittings typically cost more than compression fittings, quicker installation, less maintenance and less chance for leakage can make up for a higher purchase price. Additionally, the compact design of push-to-connect fittings is ideal for precise positioning in tight places.

Parker compression style transportation fittingCompression fittings are available in more sizes and configurations than push-to-connect fittings. Some compression fittings can support a higher PSI rating than their push-to-connect counterparts.

Compression fittings also require the use of tools to install, whereas push-to-connect fittings can be easily installed or removed without using tools, minimizing the chance of damaging equipment.

The nut on a compression fitting must be tightened correctly in order to create a seal and guard against leakage. With push-to-connect fittings, there are no compression nuts that need to be tightened. Simply pushing the fitting onto the hose or tube creates a leak free seal.

Compression fittings sometimes need to be retightened to prevent or to halt leaks. Push-to-connect fittings typically do not need readjusting in order to remain leak free.

When deciding which transportation fitting is right for your vehicle you must take into consideration:

  • Pounds per square inch (PSI) pressure requirements
  • Thread type needed
  • Type of tube or hose that you are connecting the fitting to

Also refer to your owner’s manual for your specific application.

For a clear comparison of the transportation fittings reviewed in our prior blog posts “Selecting a Parker D.O.T. Approved Push-to-Connect Air Brake Fitting” and “Choosing Compression Transportation Tube & Hose Fittings,” please refer to the table below.

Transportation Fitting Name

*Transportation Fitting Type

Thread Type Available

Pressure (PSI)

Tubing or Hose Type

NTA Compression Straight Thread & Pipe    Up to 150 SAE J844 Type A & B Tubing
Transmission Compression Pipe only Up to 150  SAE J844 Type A & B Tubing
AB Compression Straight Thread & Pipe  Up to 400 SAE J844 Type A & B, Copper, Nylon w/ Tube Support
Air Brake Hose Ends Compression Straight Thread & Pipe Up to 225 Parker 271 Hose
Vibra-Lok  Compression Straight Thread & Pipe 100 to 1000 - depending on size & vibration Copper, Aluminum, Steel (Bundy), Stainless Steel & Glass
Prestomatic  Push-to-Connect Pipe & Metric Up to 250 SAE J844 Type A & B Tubing
PTC Composite Push-to-Connect Pipe only Up to 250 SAE J844 Type A & B Tubing
Metric Prestomatic Push-to-Connect BSPT & Metric Up to 250 DIN 73378 Virgin Nylon, SAE J844 Tubing  

*All compression and push-to-connect air brake fittings are D.O.T. approved. 

Questions about Parker transportation fittings?


Posted by Linn Martinez

Topics: technical, automotive