HCMP strength

Corrosion protection engineering is crucial for HCMP strength. With three types of corrosion protection proposed by MGK, you can always pick an optimum and cost wise way for long-term and trouble-free service in a given environment.

Non-aggressive environment Aggressive environment
Air corrosivity as per PN-EN ISO 12944-2 – C1
– C2
– C3
– C4
– C5-I, C5-M
Water specifications – pH 6.5 – 8.0
– hardness ≥ 20 Ca/I mg
– flow ≤ 1.5 m/s
– pH 3.0 – 6.5 and 8.0 – 12.0
– hardness < 20 Ca/I mg
– flow > 1.5 m/s
Soil specifications – pH 6.0 – 8.0
– permeability k ≥ 6.0 m/day
– organic-free
– anisometric factor Cu ≥ 5
– humidity ≤ 17
– PH 3.0 – 6.0 and 8.0 – 12.0
– permeability k < 6.0 m / day
– organic presence
– anisometric factor Cu < 5
– humidity > 17%
Corrosion protection durability 80 um zinc coating 50 – 70 years 20 – 50 years
zinc coating + 250 um polymer coating 100+ years 80 – 100 years

«WProtect 800» extra coating

culvertsPolymer coating of galvanized steel also called «WProtect 800 train» is a technology discovered, patented, and employed in the US since 1974 and in Europe since the late 1990s.

When 250 um HDPE film is applied onto a preheated galvanized steel surface, it creates a uniform coating across the sheet surface.

The polymeric coating can be applied to one or both sheet faces.

Such a coating is the best barrier against natural zinc and steel corrosion, mechanical impacts and chemical attacks.

Test data indicate very good coating resistance to adverse chemical effects. It is the world’s best practice to protect helically corrugated pipe from corrosion known today.

If design engineering foresees such a protection, 100-year service life is guaranteed virtually in any environment.

Polymer coating aggressive agent resistance test data
Test Practice Result
10% HCl resistance ASTM D1308 No coating thinning
HNO3 resistance ASTM D1308 No coating thinning
NH4OH resistance ASTM D1308 No coating thinning
NaOH resistance ASTM D1308 No coating thinning
30% H2SO4 resistance ASTM D543, A742 No coating thinning
NaOH resistance ASTM D543, A742 No coating thinning
10% NaCl resistance ASTM D543, A742 No coating thinning
SO2 spray resistance DIN 50018,2.0L No coating thinning
Chloroform (trichloromethane, CHCl3) resistance ISO 175, 28 days, 23 °C No coating thinning
DMSO (dimethylsulfoxide (CH3)2SO) resistance ISO 175, 28 days, 23 °C No coating thinning
MeCl2 (methylene chloride) resistance ISO 175, 28 days, 23 °C No coating thinning
THF (tetrahydrofuran) C4H8O resistance ISO 175, 28 days, 23 °C No coating thinning
20% NaOH water solution resistance ISO 175, 90 days 23°C No coating thinning
80°C 8% coating thinning
10% CO (NH2)2 water solution resistance ISO 175, 90 days 23°C No coating thinning
80°C No coating thinning
25% NH4OH resistance ISO 175, 90 days 23°C 3% coating thinning
80°C *
25% H2SO4 resistance ISO 175, 90 days 23°C No coating thinning
80°C *
20% HNO3 resistance ISO 175, 90 days 23°C No coating thinning
80°C *
Isopropanol (CH3)2CHOH (isopropyl alcohol) resistance ISO 175, 90 days 23°C 4% coating thinning
80°C **
Acetone CO (CH3)2 (Propanone) resistance ISO 175, 90 days 23°C No coating thinning
80°C **
Ethyl acetate CH3CO-OC2H5 resistance ISO 175, 90 days 23°C 3% coating thinning
80°C **
Toluene C6H5(CH3) (Methylbenzyl) resistance ISO 175, 90 days 23°C 4% coating thinning
80°C Total coating damage
polyethylene glycol C2nH4n+2On+1 ressitance ISO 175, 90 days 23°C No coating thinning
80°C 4% coating thinning

* No test performed due to hazardous gas release while heating NH4OH, H2SO4, HNO3 to 80 °C;
** No test performed to exceeding the boiling temperature while heating (CH3)2CHOH, CO(CH3)2, CH3CO-OC2H5 to 80 °C.

culvertsExtra paint protection

A galvanized pipe can be further protected on one on both sides with up to 400 um paint coating.