There are a large number of criteria according to which the corrugation for cable is divided into types and categories. So, in accordance with clause 6.4 of GOST R IEC 61386.1-2014, according to the type of protection against external influences, three categories can be distinguished:
- Flame-spreading or non-flammable;
- With or without corrosion protection;
- The degree of protection against the penetration of solid particles or water is indicated by the IP index and is standardized in accordance with chapters 5 and 6 of GOST 14254-2015;
Reinforced corrugation can be used to enhance the mechanical strength of the cable protection. This grade includes steel wire around the spiral.
There is also a category of corrugated pipes with or without broaching. Broach should be understood as the presence of a steel cable, which is located along the entire length of the product. And if necessary, it can be used to facilitate the procedure of pulling the cable through the cavity.
Depending on the permissible temperature regime, the lower and upper temperature limits are distinguished. So, in accordance with clause 6.2 of GOST R IEC 61386.1-2014, there are five lower and seven upper limits:
Table 1: lower limit of temperature range
Table 2: upper limit of temperature range
In accordance with these limits, the possibility of operation, installation work or transportation of the product is determined.
Also, all corrugations can be divided according to the material from which they are made:
- Polyvinyl chloride (PVC) - is one of the most famous due to its low cost. Does not burn, but is subject to destruction under the influence of ultraviolet radiation.
- Polyethylene - depending on the manufacturing technology, high and low pressure corrugations are distinguished, which are designated LDPE and HDPE, respectively. Resistant to ultraviolet light, a number of petroleum products, some acids, etc.
- Polypropylene - like the previous type, they are made of polymer material. Possesses good resistance to external factors, does not support combustion.
- Polyamide - used as protection against moisture penetration to the cable.
- Metal - have good resistance to mechanical stress.
Not subject to combustion, destruction by oils and other active substances.
By the number of layers, one-layer and two-layer corrugations are distinguished. In the first case, there is only one layer of material, and in the second there is an inner and outer layer.