A camlock fitting, also called a cam and groove coupling, is used to connect two hoses and or pipes together in a variety of industries, so that a commodity from one can be transferred to the other. They’re easy to use, requiring no tools to connect and disconnect the two halves of the couplings and they replace the traditional time-consuming methods of some other types of hose or pipe connections. This, together with their cost effectiveness makes them the most popular coupling in the world.
You typically find camlocks in use in every industry, such as manufacturing, agriculture, oil, gas, chemical, pharmaceutical and within military applications. They’re an extremely versatile product, and because there are no threads when connecting the coupling halves together, there are no issues with them becoming damaged or dirty. This means camlock couplings are very suitable for dirty environments. The system is especially well suited to a situation where frequent changes of hoses are required, such as for petroleum, and industrial chemical trucks.
The assembly consists of a male groove adapter and female coupler. To connect and disconnect:
Measuring a metallic camlock fitting is reasonably easy. For instance, if the hose tail, male or female thread is 2” then the camlock coupling would be known as a 2” camlock coupling.
Polypropylene is slightly different. There is no international standard and different manufacturers have different head sizes. In the ½” size, the body is actually ¾” but its the thread (or hose tail) that is ½”. There are also some anomalies in the 1 ¼” sized systems.
With most cam couplings, measure the Outside Diameter (OD) of the adapter head or the Inside Diameter (ID) of the coupler. This will identify the fitting size, as depicted in the images bellow.
When specifying a fitting, there are seven fields of information required. The acronym for this is STAMPED, which stands for:
The standard for cam & groove couplings is based on the US military specification Mil-C-27487 now superseded by A-A-59326D. The original specification was replaced by the new standard, but still guaranteed the interchangeability of couplings designed to the same specification. The Mil-C-27487 specified the casting methods, materials, dimensions, tolerances, pressure ratings, and inspection procedures.
The European standard EN 14420-7 was approved by CEN in September 2004 and was applied to cam & groove couplings manufactured to the American military standard as outlined above. This American standard does not apply to the hose connection side, but only to the coupling side.
Camlock fittings produced to EN 14420-7 are interchangeable with those produced to the original MIL-C-27487 standard, but differ in terms of hose tail design, thread, and part number. A flat thread seal has been added to the female threaded parts and a smooth hose shank complying with EN 14420-7/DIN 2828 has been added for assembly with safety clamps complying with EN 14420-3/DIN 2817.
Between manufacturers, cam & groove couplings are interchangeable with the exception of ½” (12.5mm), 5” and 8”. The A-A-59326A Mil Specification does not apply to 5” and 8” cam & groove couplings due to the presence of two versions of cam & groove couplings in today’s market.
Hose shanks with larger serrations are not designed to be assembled with a ferrule or sleeve. If swaged, this can result in permanent damage to the hose where larger shank serrations will cut into the inner wall of the hose. This results in leakage and/or permanent hose failure.
There are numerous manufacturers around the world, all of which you would imagine would produce these couplings to one of the accepted standards, but experience tells us that this is not always the case.
Problems frequently arise when attempting to use one coupler half from one manufacturer with the other half made by another manufacture. This is not normally the case if the manufacturers are in North America or Europe, where the products are normally manufactured to an accepted certified specification. However cheap copies use less materials in the construction of the coupling and as a result will not last as long. Some are even being made from reused scrap material. I addition their manufacturing process often involves manually drilling-out the fitting so consistency is often a problem, leading to couplings that do not always connect together properly.
Products supplied from reputable manufacturers are designed to be used in rugged situations and if maintained correctly will give a long life, and in the case of Stainless Steel, the materials can be traced.