∆P gauge quickly spots leakage

Fluid power assemblies must be tested for leakage. The three traditional, low-tech approaches for doing so are:

• Filling the assembly with compressed air, then slopping soapy water on it to see if bubbles reveal leaks.
• Immersing the whole assembly in a water bath, then pressurizing it with air — again, watching for bubbles.
• Pressurizing the sealed assembly and watching a gauge for pressure decay.

At best, these methods are cumbersome and time-consuming. At worst, they add drying and corrosion problems. All interrupt production flow. A simple, high-speed leakage test, suitable for production work, can be assembled from a differential-pressure gauge, a pair of two-way valves, and a vessel that is known to be leak-free. The circuit is shown in the accompanying illustration.