Which coupling system should I choose: cam and groove, tanker, Guillemin or Storz?

You need a dry disconnect coupling when not a single drop of product or any vapour may escape on disconnection, because it is harmful to people or the environment. This applies, for example, when loading and unloading tank trucks and tank containers and on pipelines in the (petro)chemical industry.

A dry disconnect coupling consists of a male part, the tank unit (on the tank or pipeline), and a female part, the hose unit (on the hose). Both parts contain check valves. When connecting and rotating, the valves open to create a free passage; when disconnecting, they close completely again so that nothing leaks out.

Well-known systems include TODO-MATIC and Mann Tek. Various brands work on the same principle and are in many cases interchangeable; do check this for each version. Where several products are loaded or unloaded side by side, dry disconnect couplings can be fitted with selectivity coding. This prevents, for example, a diesel hose from being connected to a kerosene connection.

For loading and unloading tank trucks, dry disconnect couplings, tanker couplings (TW) and cam and groove couplings (camlock) are mainly used. For products that must not leak or release vapour, a dry disconnect coupling is the safest choice: on disconnection, the check valves on both sides close immediately.

The difference from a regular flange coupling lies in speed and shut-off. A flange connection is fitted with bolts and nuts and is highly reliable under pressure, but it is not designed for frequent, quick connection and disconnection. A dry disconnect coupling is made precisely for frequent coupling without product loss.

Many companies also work with a dedicated hose: a hose used exclusively for one product, so that no residues of other products end up in it. Combined with an additional product valve on the coupling, this creates a very safe solution.

A food coupling is designed so that there is no gap in which product or contamination can remain. The coupling is therefore crimped onto the hose as standard, leaving no space between the hose tail and the hose. The connections themselves are also designed so that nothing can get in between.

With a standard water coupling, this hardly matters, as some contamination is not a problem with industrial or rinsing water, for example. The difference becomes relevant as soon as the medium is a foodstuff, such as dairy, juices or beverages, or when drinking water is involved. Hygiene and cleanability then determine the choice.