A cam and groove coupling, also called a camlock fitting, is a form of

hose coupling A hose coupling is a connector on the end of a hose to connect (or ''couple'') it with another hose or with a tap or a hose appliance, such as an irrigation sprinkler. It is usually made of steel, brass, stainless steel, aluminium or plastic ...

. This kind of coupling is popular because it is a simple and reliable means of connecting and disconnecting hoses quickly and without tools.

Standards

Traditionally manufactured to US Military Specification MIL-C-27487, this specification covered the dimensions and machining tolerances, materials, closing torque, part numbers, pressure ratings, finish, inspection procedures and packing requirements. Compliance to this specification ensured inter-changeability of parts from different manufacturers. In 1998, the specification A-A-59326 replaced MIL-C-27487. In Europe the standard BS EN 14420-7 applies as well as the German

DIN DIN or Din or din may refer to: People and language * Din (name), people with the name * Dīn, an Arabic word with three general senses: judgment, custom, and religion from which the name originates * Dinka language (ISO 639 code: din), spoken ...

2828 standard. Products produced to DIN 2828 are interchangeable with those made to the original MIL-C-27487 but have differences in the hose tail design, thread, part number and other details.

Function

The cams at the end of each lever on the female end align with a circumferential groove on the male end. When the levers are rotated to the locked position, they pull the male end into the female socket, creating a tight seal against a

gasket Some seals and gaskets A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. It is a deformable material that is used to c ...

within the female socket. The arms lock into position using over-center geometry, preventing accidental decoupling. Further, lever safety pins are common features for additional security, and female-end "self-locking" levers are also available. Because the groove is cut all the way around the male end, there is no specific rotational alignment necessary to couple, as there would be with

threaded connector In plumbing and piping, a nipple is a fitting, consisting of a short piece of pipe (material), pipe, usually provided with a gender of connectors and fasteners, male national pipe thread, pipe thread at each end, for connecting two other fitting ...

s, and there is no opportunity for cross-threading. This results in a fast, error-resistant coupling operation. Because the compression between the two fittings is limited by the size of the cams on the end of the levers and the rotation of the levers themselves, there is also no possibility of over- or under-tightening the fitting; the pressure against the sealing gasket is effectively constant from one coupling operation to the next, reducing possibility of leaks.

Materials and uses

Cam and groove fittings are commonly available in several materials, including

stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

brass Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. I ...

, and

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene. Polypropylene belongs to the group of polyolefin ...

. Because there are no threads to become fouled, cam and groove couplings are popular in moderately dirty environments, such as septic tank pump trucks and chemical or fuel tanker trucks. The system is especially well suited to a situation where frequent changes of hoses are required, such as for petroleum trucks, etc. As examples of industrial application, cam and groove fittings can be used in a system where rapid filling of chemical drums takes place, or by factories that have needs of dye, paint, and ink medium transfers. Note: Cam and Groove couplings are not recommended for any type of

compressed gas Bottled gas is a term used for substances which are gaseous at standard temperature and pressure (STP) and have been compressed and stored in carbon steel, stainless steel, aluminum, or composite containers known as gas cylinders. Gas sta ...

service, including steam or air.

Types and sizes

Generally speaking, the most common types of cam and groove coupling are the following types. The letter codes are the common designations, while the roman numeral codes come from the

GSA GSA may refer to: Commerce * Citroën GSA, a French automobile * GameSpy Arcade, a utility for use with network computer games * General sales agent, an airline sales representative * Global mobile Suppliers Association, a not-for-profit indust ...

CID Cid may refer to: * Cid (soil) * Cubic inch (c.i.d., cid), a displacement unit for internal combustion engines * Cid, a slang term for lysergic acid diethylamide (LSD) * Content-ID, a URI scheme (cid:) that allows the use of MIME within email Peop ...

A-A-59326 standard: *Type A or Type I: adapter (male end) with female thread, e.g. BSP or NPT *Type B or Type VII: coupler (female end) with male thread, e.g. BSP or NPT *Type C or Type VI: coupler with

shank Shank may refer to: Objects * Shank (footwear), part of a shoe or boot * Shank (sewing), a spacing device * Shank (weapon), a makeshift knife or stabbing weapon * Lead shank, a type of lead used for horses * Tang (tools), the back portion of th ...

(hose barb) *Type D or Type V: coupler with female thread *Type E or Type II: adapter with shank *Type F or Type III: adapter with male thread *Type IV: adapter with flange, TTMA (Truck Trailer Manufacturer's Association) *Type VIII: coupler with flange, TTMA *Type DC or Type IX:

dust cap The dust cap (also known as dust dome, or dome) is a gently curved dome mounted either in concave or convex orientation over the central hole of most loudspeaker diaphragm (acoustics), diaphragms. It protects the inner mechanics (such as the ''p ...

s (female) *Type DP or Type X: dust plugs (male) Apart from these basic types, the hose/pipe connection side of a cam and groove coupler can be of various other types such as with a

flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of a steel beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer o ...

, for

butt welding Butt welding is when two pieces of metal are placed end-to-end without overlap and then welded along the joint (as opposed to lap joint weld, where one piece of metal is laid on top of the other, or plug welding, where one piece of metal is inser ...

to a container, for truck use with a

sight glass A sight glass or water gauge is a type of level sensor, a transparent tube through which the operator of a tank or boiler can observe the level of liquid contained within. Liquid in tanks Simple sight glasses may be just a plastic or glass tube ...

, etc. These couplings are available in the following diameters:

Gallery

Image:Camlock type B.JPG Image:Camlock type C.JPG Image:Camlock type D.JPG

References