Leak testing is a broad term that includes a multitude of technologies. For the purposes of this article, different leak test methods will be referenced but not described in full detail. This article defines the broad term leak test and takes a closer look at the pressure decay leak test method. Furthermore, this article will describe how a pressure decay test works, considerations for the pressure decay method, and how recent technological advancements have impacted manufacturing environments.
What is Leak Testing?
A fixed head leak tester is a procedure used to determine if an object, product, or system functions within a specified leak limit. A leak occurs when a gas or liquid flows through an object via an imperfection or manufacturing defect such as a hole, crack or weak seal. These imperfections create high- and low-pressure zones within a product, forcing the gas or liquid to flow from the high-pressure area to the low-pressure area. The primary leak test method discussed in this article uses pressurized air to identify leaks.
Leak Testing Methods
There are many different types of leak test methods, which have different detectable leak rate limits. This article will primarily discuss the pressure decay leak test method. A pressure decay test identifies if a part is leaking or not within a predetermined leak rate limit. The smallest detectable leak rate for the pressure decay method is 10-4 mbar*l/s or 0.0059 SCCM.
The benefits of pressure decay leak testing include:
Design
During the design and development of a product it is important to consider the test criteria to ensure a part has been manufactured correctly. Design criteria such as test pressures, access ports, shared walls or vessels, internal test volumes, and leak rate specifications all have an impact on the complexity and time required for a leak test. How the object connects to a leak test system helps to determine what kind of leak test will be run on the object. A fully enclosed object with no port to fill the item, such as a waterproof enclosed electronic device, requires a chamber test which includes a sealing fixture. An object with one port or opening, such as a catheter, can be directly connected to the front port of a leak tester without a fixture.
Conveyor has been a staple in the materials handling industry for decades. As the demand for reduced cost, increased throughput and integrated automation grows, so does the need for conveyor systems of all types.
Conveyor is available in many styles and is used in countless applications. In this Equipment 101 article, Modern spotlights the basics of some of the most common conveyor types:
? Non-powered skatewheel and roller conveyor
? Powered, or live, belt and roller conveyor used in handling packages and other small products
? Powered chain and roller conveyor used in handling pallet loads of goods
