It might surprise you that mismatched fittings are among the most common reasons for leaks and hydraulic system failure.
However, with this guide on how to size hydraulic fittings, you and your hydraulic systems can avoid becoming another statistic.
Understanding Hydraulic Fittings
A hydraulic hose fitting part is an essential part of all hydraulic systems. They connect the hydraulic hose and pipes to other component parts, preventing leaks and ensuring the whole system functions as it should.
There are two basic types of hydraulic fittings: high-pressure and low-pressure. Both come in a wide variety of shapes, such as elbows, tees, crosses, and straight fittings. These are further divided into categories, including single-ring, double-ring, push-in, and push-on fittings. Common materials for hydraulic fittings include aluminium, brass, stainless steel, and plastic.
Factors to Consider When Sizing Hydraulic Fittings
- Hydraulic fluid type and compatibility with fittings.
- Pressure rating requirements for fittings.
- Flow rate considerations for proper sizing.
- Temperature and environmental factors affecting fitting selection.
- Remember that two hydraulic fittings that look the same don’t necessarily have the same measurements – always check.
Steps to Size Hydraulic Fittings
Follow these steps for an accurate thread identification, inner diameter and outer diameter or male and female measurement
1. Measure The Length
This is easily done with a simple tape measure. Place the fitting on a flat surface and measure it with the tape.
2. Determine The Outside Diameter
The outside diameter, also called the male thread hydraulic fittings, can be worked out with vernier callipers. First, zero the callipers out, then place the fitting between the parallel threads of the jaws before closing them until they hold the fitting tightly.
This method provides highly correct readings. Remember the axiom about measuring twice? Apply it here to save yourself bother later down the line.
3. Measure The Inside Diameter
For the female thread measurement process the steps are similar to that of the male thread. This time however place the vernier calliper jaws inside of the fitting to give precise readings. As before, measure twice and this will give you accurate measurement.
4. Work Out The Thread Gauge
The gauge teeth of a thread pitch gauge determine the thread gauge. Place it on the threads you need to measure. Make sure it is a tight fit with no gaps between the fitting and the teeth. You can then check on the manufacturer’s websites or catalogues to find a matching thread so you know it will be the correct measurement.
If you don’t have a thread pitch gauge, you can get out your Vernier callipers again to get an estimate. With British and European threads, thread gauge is measured by threads per inch so simply count the number of threads an inch.
5. Determine The Angle
The angle of your fitting is very important. The most common angles of elbow fittings are 45° and 90°, but it is important to measure with a protractor to get an accurate measurement as they can vary.
Conclusion
Hydraulic fitting sizing is very important to get right to ensure your system works efficiently and safely without leaks, even getting measurements slightly wrong can severely impact performance. By following the step-by-step guide and the tips in this article you should be able to size your hydraulic fittings accurately.
As with any hydraulic system issue, it is always recommended that you seek professional support with anything you and your team are not suitably qualified and confident to do.