Cam and Groove Fittings Review Mar. 23, 2015

Intro

Cam and groove couplings are also called cam lock fittings. These are quick connect couplings commonly used in various industries as a hose connection to prevent leakages. The coupling is well-known because it is an easy and inexpensive way of connection, reconnection or disconnecting.

Cam and groove couplings can be used in a system in which filing of chemical drums is required. These can be utilized by factories that require paint, dye and ink medium transfers. The couplings are generally used wherein frequent modifications of hoses are necessary for an appropriate mix. Even cam and groove couplings are useful for petroleum trucks.

Application. Cam & groove couplings are used for hose-to-hose or hose-to-pipe / manifold connections for the transfer of liquids or dry bulk products with the exception of liquid gas and steam.


Standards

Federal Mil A-A-59326A

The standard for camlock fittings is based on the specification of the US Military i.e. Mil-C- 27487. Mil-C-27487 assigned the methods, dimensions, inspection procedures, materials, pressure ratings and tolerances. In 1998, the actual Mil-C-27487 specification was changed by another Federal Military standard: A-A-59326A. The Federal Mil A-A-59326A offers complete guarantee for the exchangeability of cam and groove couplings designed to the similar specification.

Interchangeability with other brands Between manufacturers cam & groove couplings are interchangeable with the exception of 1/2" (12.7 mm), 5" (127 mm) and 8" (203.2 mm). 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.

Limitations: Hose shanks with larger serrations are not designed to be assembled with a ferrule or sleeve. Hose damage can result if they are swaged. The larger shank serrations will cut into the inner wall of the hose resulting in leakage or permanent hose failure.

N.B.: Cam & groove couplings must never be used for steam or compressed air applications.

DIN 2828

Couplings designed to DIN 2828 are exchangeable with those which designed to the actual MIL-C-27487 standard. However, vary in terms of part number, thread and hose tail design. A flat thread seal has been added to the female threaded parts, and a smooth hose shank complying with DIN 2817 has been added for assembly with RK safety clamps complying with DIN 2817.

EN 14420-7

The European standard coupling (EN 14420-7) is official approved by CEN and useful for cam and groove couplings designed to American “military specification” A-A-59326A / MIL-C- 27487. However, the American standard coupling does not apply to the connection side and just to the coupling side. However, the other parts such as seals, rings, levers and bolts are not interchangeable.

Cam & groove couplings 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, part number etc. A flat thread seal has been added to the female threaded parts, and a smooth hose shank complying with EN 14420-2 / DIN 2817 has been added for assembly with RK safety clamps complying with EN 14420-3 / DIN 2817. N.B.: European standard EN 14420-7 replaces DIN 2828 but does not replace MIL-C-27487 and Federal Mil A-A-59326A.


Types of Cam & Groove Couplings:

TYPE A: An adapter with the female thread popular standard of thread is NPT or BSP

TYPE B: A coupler with the male thread popular standard of thread is NPT or BSP

TYPE C: A coupler with hose barb

TYPE D: A coupler with the female thread popular standard of thread is NPT or BSP

TYPE E: An adapter with shank

TYPE F: An adapter with the male thread poplar standard of thread is NPT or BSP

TYPE DP: A dust plug

TYPE DC: A dust cap

 


Operation

to Connect:

  1. In order to start, you first need to open the coupling by pulling back its locking lever above the cam handles. Do this process from the top cam handles while moving the handles away from the coupler.

  2. Now insert its adaptor into the cam and groove coupler.

  3. Close the coupler by turning the cam handles. Make sure the arms are closed in the direction of the coupler and then lock it once the handles get closed.

  4. If you want more security, insert the clip from holes above cam handles. The line pressures move the adaptor and coupler independently and increase the pressure on the face of coupling, ensuring increased locking leverage. Under normal conditions, safety locks are not required but these are essential. The coupler and the adaptor are created  to minimize the fluid turbulence and the abrasion from dry products when connected.


to Disconnect:

  1. Before disconnecting, ensure that the hose coupling is completely depressurized.

  2. To open the coupler, pull back its locking lever above the cam handles while turning handles away from the body of the coupler.

  3. Take out the adaptor from the cam lock coupler.

  4. Close the coupler by lowering cam handles. Locking the coupler when it is not in use will help protect it from any accident or damage.


Industries Where Cam and Groove Couplings Are Used:

  • Fire fighting

  • Agriculture irrigation

  • Food and beverage

  • Oil and refinery

  • Construction

  • Chemical

  • Colliery

  • Sanitary

  • Water treatment

   
   

Materials

Cam and groove couplings and accessories can be found on our site in the following materials:


Threads

Three different types of thread are generally used for cam & groove couplings:

  • BSP = British Standard Pipe thread

  • BSPT = British Standard Pipe Taper thread

  • NPT = National Pipe Taper thread

In Europe, BSP and BSPT threads are more commonly used than NPT threads. NPT threads are typically American threads. Since many American industrial machines and products are exported to European markets, couplings with NPT threads are a regular requirement. The main difference between the three thread types referred to above is the seal method used. Although BSP threads are sealed using a seal or o-ring, BSPT and NPT threads are sealed by their conical thread.

Question And Answer