Importance of Pressure Ratings and Testing for Hydraulic Fittings

Tuesday, August 13, 2019

It can be difficult to find the right hydraulic fitting or adapter. With so many options available, it can be overwhelming to choose the one that is ideal for your application. While you can simply pick one and hope for the best, we recommend paying attention to pressure ratings as pressure is one of the most important things to consider when you’re evaluating hydraulic adapters and systems.

Manufacturers usually disclose the pressure ratings of their hydraulic fittings.

Most manufacturers, including us post pressure ratings directly on their websites. It’s important to ensure the fitting you select has a maximum working pressure that is above what your system’s working pressure is. This way, your system won’t have any issues handling temporary pressure surges.

View Air-Way Mfg Pressure Ratings (general reference) here

View Air-Way Mfg Steel Tubing Pressure Ratings here

The rated working pressure for any fitting is based on the lowest pressure rated fitting end. For instance, a fitting may include one -4 (1/4") male 37 degree tube end and one -6 (3/8") male pipe end.

To ensure  proper performance, the design of any hydraulic system should take into consideration the rated working pressures for each of the components of the system. This  includes the standard ratings for hose and tubing components and assemblies.

The lowest rated working pressure of the above variables should be considered the maximum working pressure of the system.

In addition to considering pressure ratings, pay attention to the testing of hydraulic fittings. The most widely used test methods include:

Proof Test (minimum 2 times maximum working pressure)

Also known as non-destructive hydrostatic pressure test of a hose assembly and adapters, a proof test can be used to prove the product prior to use.  If there are any signs of bulging, leakage, or hose burst below the minimum rated proof pressure, the proof test has not been passed.

Burst Test (minimum 4 times maximum working pressure)

Also known as a destructive hydrostatic pressure test of a hose assembly and adapters, a burst test determines burst strength. If there are any signs of bulging, leakage, or hose burst below the minimum rated burst pressure, the burst test has not been passed.

Impulse Test – Cyclic Endurance

An impulse test can predict the life of the hose. During this test, the hose or adapter is pressurized up to 133% of the working pressure at a frequency of up to 6 Hz for the amount of cycles designated by the appropriate national or international standard.

Adapters are always tested to a minimum of 1,000,000 cycles. 

Hose assemblies are tested at a specified bend radius.

Salt Spray Test

The salt spray test evaluates how resistant materials and surface coatings are to corrosion. It involves creating a corrosive attack to the test sample to check and compare the suitability of the coating used. To combat corrosion, we offer several different plating options, as well as stainless steel options, for our fittings. View our primary plating options here.

Contact Air-Way For More Information

For more details on pressure ratings for our hydraulic adapters and fittings you can visit that section of our catalog here, or for more information about our testing processes, we invite you to contact us today.