The transmission tower building and maintenance are of great importance for Russia. The strength and durability of transmission towers are provided by methods including corrosion protection.
One of the methods to protect the transmission towers is a "cold galvanizing”, which consists of application of zinc-rich primers. These coatings have incontestable advantages such as:
- provide high performance protection of steel structures, not less than hot-dip galvanizing;
- have resistance to the temperature drop and can be applied at cold climate;
- can be applied by spraying and brushing in the shop and field conditions;
- are non-flammable.
VMP HOLDING is the leading "Cold galvanizing" coating supplier in Russia and recommends for protection of power industry steel structures such the coating system as:
ZINOL (2 coats) + ALPOL (1 coat)
Total dry film thickness - 120-140 microns
Zinc-rich primer ZINOL contains up to 96% (Wt) of metal zinc and has the electrochemical properties similar to the traditional zinc-coating and the same cathodic steel protection. ALPOL coating with leafing aluminium pigments provides additional corrosion protection. This coating system has aluminium color, high decorative effect, cathodic and barrier types of protection and provides higher performance in comparison with the different methods of steel protection.
In non-aggressive environments ZINOL+ALPOL coating system has an expected durability of 25 years or more; in industrial environments – more than 15 years. The coating system is recommended for new buildings and constructions and for maintenance and repair without the dismantling.
ZINOL+ALPOL coating system is certified by the interdepartmental committee of Federal Grid Company of Unified Energy System and included in STO 56947007-29.240.55.016-2008 and STO 56947007-29.240.10.028-2009.
ZINOL+ALPOL coating system successfully passed tests and have certificates and conclusions of the leading industrial institutes: Central Scientific and Research Design Institute n.a. Melnikov, NIIZHB, OJSC TSNIIS, NICIAMT FSUE "NAMI", OJSC VNIIZHT; recommended by Gosstroy R (SNIP 2.03.11-85); included in GOST 9.401-91.
ROSTECHNADZOR recommends the method of “cold galvanizing” with using of zinc-rich primers for protection of steel structures of the transmission towers and switching centers of substations.
"Cold galvanizing" advantages compared traditional coatings with regard to the transmission tower
||Hot-dip galvanizing ||Traditional coating |
|1. application conditions ||shop and field application ||shop application ||shop and field application |
|2. equipments for application ||ordinary equipments for application ||special lines ||ordinary equipments for application |
|3. requirements to protected constructions ||any constructions without size limits including large-size constructions ||size and type limits ||any constructions without size limits including large-size constructions |
|4. mechanism of protection ||cathodic (sacrificial protection) and barrier ||cathodic (sacrificial protection): under the influence of aggressive environments and in the presence of the damage on the coating the zinc is oxidized instead of the underlying steel preventing of steel corrosion and products of zinc corrosion seals coating damages ||barrier: coating prevents access of corrosive environments to the underlying steel by barrier effect |
|5. expected durability in industrial environments ||more than 15 years * ||not more than 12 years * ||2-4 years |
|6. maintenance and repair ||repair-suitable ||not repair-suitable ||repair-suitable |
|total characteristics of the method of the transmission tower protection ||high performance and easy application ||size and type limits of constructions; durability limits in aggressive environments ||low performance |
* - in aggressive environments the expected durability of VMP-coatings is in two times higher in comparison with hot-dip it is confirmed by testing in NICIAMT FSUE "NAMI", OJSC VNIIZHT
the high-tension transmission line towers 500 кV:
- Tyumen-Berkut, Tyumen Oblast, Russia;
- Barabinsk-Tavricheskaya, Omsk Oblast, Russia;
- PrimGRES-Khabarovskaya, Khabarovsk Kray, Russia;
- Ishim-Tobolsk, Tyumen Oblast, Russia;
the high-tension transmission line towers 220 кV:
- Idrim- Vanzetur, Khanty–Mansi Autonomous Okrug;
- Severnaya - Kosmos, Perm Krai, Russia;
the gantries PS 500 kV:
- Shelekhovskaya, Irkutsk Oblast, Russia;
- Cenralnaya, Krasnodar Kray, Russia;
- Kirpichnikovo, Khanty–Mansi Autonomous Okrug, Russia;
- Lipeskaya, Lipesk Oblast, Russia;
the gantries PS 110 кV:
- Skovorodino, Amur oblast, Russia;
- Angelovo, Moscow oblast, Russia.