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