galvanized steel pipe
Galvanized steel pipe protect the pipe from corrosion
What is galvanized steel pipe
Galvanized steel pipe is the carbon steel pipe that are coated with a protective layer of zinc. The zinc layer served as a sacrificial layer, it will get rust before the carbon steel under neath it. Galvanized layer will strengthen the anti-corrosion performances of steel pipe.
Galvanized steel pipe types
Galvanized steel pipe include two kinds:
- Hot dipped galvanized steel pipe.
- Cold galvanized pipe, also called electric galvanized pipe.
Hot dipped galvanized steel pipe introduction
Hot dipped galvanized steel pipe is in manufacturing process using steel pipes of removed rust dipped into zinc liquid of 500℃ temperatures, and making steel surface attached zinc layer so as to achieve the purpose of anti-corrosion.
The processing of hot galvanizing:
Finished pickling – washing – plating – drying – hanging plating – cooling – medicine – cleaning – grinding – hot galvanized finish.
Cold galvanized steel pipe introduction：
Cold galvanized steel pipe is using electric chemical processing coated zinc layer on steel pipe. The zinc layer usually 20~30μm thick.
Manufacturing process of cold galvanized steel pipe:
Degreasing – electroplating – passivation – drying – packaging
How long of hot galvanized steel pipe lifetime?
Galvanized steel pipe have long lifetime. But in different conditions the lifetime of use are different. Generally speaking, 13 years in heavy industrial district, 50 years for ocean environment, 104 years in suburbs, 30 years in city. In fact galvanizing have played a role of anti- rusty, it is no need other rust treatment.
Application of Galvanized steel pipe
Galvanized pipe is an excellent choice for many applications and processing techniques. So galvanized is widely applied for many industries :
- Hot and cold liquid transportation
- chemical industry
- electric power
- Exposed environments
- Marine environments
- coal mining
Advantage of galvanized steel pipe
Galvanized pipe maintains a wide range of benefits, suitable for use in highly corrosive environments. The semi-smooth, zinc finish of galvanized steel pipe provides a layer of protection that is not seen in other types of protective materials.
Main advantages of galvanized structural pipe include:
- Protects against corrosion and rust
- Increased structural longevity
- Overall enhanced reliability
- Affordable protection
- Easy to inspect
- Less repairs
- Rugged toughness
- Easier to maintain than standard painted pipes
- Protected by advanced ASTM standardization
Galvanized steel pipe sizes and specifications
|Nominal diameter (inch):||1/2~4|
|Nominal wall thickness (mm):||2.0~4.5|
|Test pressure index:||Diameter: 10.2~168.3 mm 3 MPa|
|Diameter: 177.8~323.9 mm 5 MPa|
|Schedule:||sch40, sch80, sch120, sch160, XH, XXH|
Tolerances of the zinc coated tubes
- Tolerances of the outside diameter:
- Diameter between 4 – 30 mm ±0,08 mm
- Diameter between 35 – 38 mm ±0,15 mm
- Diameter up to 42 mm ±0,20 mm
- Tolerances of the inside diameter are according to en 10305-4
- Tolerance of the wall thickness ± 10%