Galvanized Welded Pipe

Galvanized Welded Pipe mainly includes hot galvanizing and cold galvanizing. Galvanized welded pipe is a welded steel pipe with a hot-dip or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of steel pipes and prolong their service life.
Galvanized welded pipe is a kind of protective layer formed by coating a layer of zinc on the surface of ordinary welded steel pipe, and after heat treatment, the zinc is firmly attached to the surface of the steel pipe, so as to achieve the purpose of prolonging the service life of the steel pipe.

Galvanized welded pipe production process:
Plate detection、milling、pre-bending、forming、pre-welding、inner welding、outer welding、ultrasonic inspection Hot-dip galvanizing is to pickle the steel pipe first, In order to remove the iron oxide on the surface of the steel pipe, After washing, it is washed in an ammonium chloride or zinc chloride aqueous solution or a mixed ammonium chloride and zinc chloride aqueous solution tank, and then sent to a hot-dip coating tank. Galvanized welded pipe are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipelines in the petroleum industry, especially in offshore oil fields, and oil heaters for chemical coking equipment. Pipes for condensing coolers, coal distillation washing oil exchangers, trestle piles, and supporting frames for mine tunnels, etc.

Product Features of Galvanized Welded Pipe
1. High strength: Galvanized welded pipe has very high strength. The chemical reaction of iron and zinc forms a Zn-Fe alloy layer on the surface of the galvanized welded pipe. This alloy layer makes the galvanized welded pipe have strong tensile strength and flexural strength.
2. Corrosion resistance: Galvanized welded pipe has strong corrosion resistance. Zinc is a metal with excellent oxidation resistance, so galvanized welded pipe has very good corrosion resistance.
3. Pressure resistance: Galvanized welded pipe also has good pressure resistance. Manufactured from high-strength steel, this steel pipe is capable of withstanding high compressive forces.
4. Non-toxic: Galvanized welded pipe does not contain any harmful substances, so it has no harm to human body and environment.
5. Easy processing: Galvanized welded pipe has good processing performance and can be processed by various methods.
6. Recyclability: Galvanized welded pipe has good recyclability and can be recycled and reused.

Application range of galvanized welded pipe
Galvanized welded pipe has a wide range of applications, mainly in construction, manufacturing, petrochemical, aviation, automobile, pipeline and other fields.
In the field of construction, it is mainly used to construct building frames and building supports, and can also be used to manufacture regulatory pipelines, water conservancy projects, roof drainage systems, etc.
In the field of manufacturing, it is mainly used to manufacture machinery and equipment, auto parts and heavy machinery parts.
In the aviation field, it is mainly used to manufacture brackets and connectors of aircraft structures.

To sum up, galvanized straight seam welded steel pipe has the characteristics of strong corrosion resistance, smooth surface and high strength. 

The standard of galvanized welded pipe can vary according to different countries and regions. Production and quality comply with country-specific standards to ensure safety and performance in specific applications. The following are the implementation standards of some common countries:

Chinese standard:
GB/T 3091-2015 "Welded steel pipe for low-pressure fluid transmission", GB/T 13793-2016 "Straight seam electric welded steel pipe", GB/T21835-2008 "Welded steel pipe size and weight per unit length"

British Standard:
BS 1387 "Specifications for heavy and ordinary welded carbon steel pipes", BS EN 10255 "Specifications and grades for non-alloy steel pipe threads and corrosion-resistant coated steel pipes"

American standard:
ASTM A53/A53M Standard Specification for Welded and Seamless Steel Pipe, Black Painted or Hot Dip Galvanized, ASTM A795/A795M Standard Specification for Black Painted or Hot Dip Galvanized Steel Pipe for Fire Protection Service

Japanese standard:
JIS G 3442 "Specifications for Galvanized Steel Pipes"

This standard specifies the classification and code, order content, size, shape, weight and allowable deviation of welded steel pipes, technical requirements, test methods, inspection rules, packaging, signs and quality certificates.

The lower difference range stipulated by the national standard of galvanized pipe refers to the allowable range of dimensional deviations such as pipe wall thickness, length, and outer diameter. According to national standards, the range of galvanized pipes should meet the following requirements:

Length 3m—16m
Outer diameter 20mm—1680mm;
Wall thickness 0.5mm-30mm;

The length deviation of the galvanized pipe shall not be greater than ±5mm.
The outer diameter deviation should not be greater than ±0.15mm.
The wall thickness deviation shall not be greater than 10% of the pipe wall thickness.

Specifications for allowable deviations in wall thickness of galvanized steel pipes:
1. The deviation level is D1, the allowable deviation of the standardized outer diameter is +1.5%, and the minimum is 0.75mm
2. The deviation level is D2, the allowable deviation of the standardized outer diameter is +1.0%, and the minimum is +0.50mm
3. For D3 deviation level, the allowable deviation of the standardized outer diameter is +0.75%

By controlling the drop range of the galvanized pipe, the dimensional stability and quality reliability of the galvanized pipe can be guaranteed. Therefore, when choosing a galvanized pipe, it is necessary to carefully check whether its size meets the requirements of the national standard to ensure the use effect and safety.