Leak Testing [LT]

The methods used vary from simple bubble testing combined with a visual inspection, to very sensitive methods using radioactive gases. Inspectors can detect leaks within a vessel using measurements taken with a pressure gauge, or electronic listening devices, among others. Three of the most commonly used types are:

• Pressurised Fluid
• Pressurised Air/Gas
• Vacuum

Pressurised Fluid, where leaks are detected visibly or through measured decay by specialised fluid pressure gauges or electronic sensors:
• simulates real-world conditions for parts designed to contain or pass fluid.
• performs superbly for testing at pressures above 500PSI.
• may be used for destructive testing (pressurise to burst).

Pressurised Air/Gas, where leaks are detected visibly when immersed in a fluid, or audibly when using sensitive “listening” devices or by electronic sensors when using pressure-decay instruments:
• is fast: as air molecules are roughly 500X smaller than water molecules. Can detect much smaller voids in parts in considerably less time than fluid testing.
• has low cost: sensitive equipment is available by many manufacturers at far lower costs than sensitive fluid systems.
• is clean: parts do not have to be cleaned of fluids after the test.

Vacuum, where leaks are detected visibly when immersed in a fluid (liquid entry into part) or by specialised electronic vacuum sensors or gauges with vacuum-decay instruments:
• is ideal for parts that will have an internal vacuum applied.
• can create leak paths that cannot be replicated by pressure testing such as dynamic seals (“o” rings and rubber diaphragm valves).

Pressurised Fluid
• Added Costs: parts often require cleaning/drying after test.
• Time Consuming: the time required for fluid to leak through a small void in the part can be considerable, sometimes hours.
• Messy: fluid gets everywhere when testing using this method.
• Costly Equipment: is often custom made per application

Pressurised Air/Gas
• Very costly to achieve pressures above 500PSI.
• As air compresses so much more than fluid, can be difficult to use for some destructive tests.
• Only represents (does not duplicate) “real-world” testing for parts containing or passing fluid.

Vacuum
• Not good for testing parts that would otherwise have pressure applied internally in actual application as the vacuum may inadvertently seal small voids in flexible parts.
• Vacuum is limited to approximately -14.7 PSI (ideal vacuum). With typical vacuum pumps, only -10 PSI or so may be possible.

Leak testing is typically used to detect small leaks in products including, but not limited to: valves, welds, manifolds, high purity piping, hydraulic lines, storage tanks, and more.

Newtron Leak Testing can be used to assess a wide array of assets in a range of industries like Oil and Gas, Automotive, Manufacturing, Maritime, Energy.