Precautions in the use of anticorrosive steel tubes

- Apr 20, 2019-

Precautions in the use of anticorrosive steel tubes

3PE anticorrosive steel pipe, national standard 3PE anticorrosive steel pipeThe pipe end of this anticorrosive coating is prone to warping due to corrosion.According to the analysis, when grinding the groove of the polyethylene layer in the reserved section of 3PE anticorrosive steel pipe, the remaining height of the welding seam at the end of the pipe is not polished or polished unevenly, which will cause the epoxy powder at the bottom of the polyethylene protruding part of the welding seam to be ground

National standard 3PE anticorrosive steel pipe during the use of matters needing attention, anticorrosive steel pipe factory, thermal insulation steel pipe factory three-layer structure polyethylene (3PE) anticorrosive coating with its good corrosion resistance, water and gas permeability and mechanical properties, etc., in the oil pipeline industry has been widely used.The pipe end of this anticorrosive coating is prone to warping due to corrosion.Analysis: the 3 PE anticorrosion layer steel pipe in reserve period of polyethylene polishing groove, pipe weld residual high grinding and grinding uneven, lead to weld highlights polyethylene epoxy powder is at the bottom of the ground, in the case of anticorrosion pipe long deposited in the open air, the surface of the weld metal will be corrosion, leading to 3 PE coating become warped edge.1. Without affecting the welding of the pipe end, the reserved length of epoxy powder at the end of the polyethylene layer should be appropriately increased to prevent the 3PE anti-corrosion warping caused by the long stacking time of the steel pipe and the serious metal corrosion at the end.2. When the anticorrosive pipes are stored in the open air for a long time, they shall be covered at the end of the pipe to prevent the erosion of rainwater and cause severe corrosion of the pipe end.3. If the on-site construction period of the pipeline is relatively long, weldable anti-rust paint can be applied on the exposed metal of the pipe end to prevent the anti-corrosion pipe from warping the anti-corrosion layer of 3PE due to corrosion during storage.4. Strictly control the high grinding quality of welding seam remaining at the reserved pipe end.Like other parts of the pipe body, the epoxy powder retained the length of >20mm outside the polyethylene groove at the welding seam to prevent the bottom of the epoxy powder at the welding seam from being corroded first and causing the warping of the 3PE anticorrosive coating.Note: 1) from the beginning of weld grinding to the chamfering Angle of polyethylene, there should be a 10-20mm flat section of polyethylene layer like the pipe body without weld residual height, so as to ensure the quality of extrusion bonding at the groove of polyethylene at the pipe end.2) the residual height of the welded seam should be as level as possible with the pipe body, without obvious residual height, to prevent the epoxy powder from being polished away together when polishing the chamfering Angle of the polyethylene layer.


Cangzhou Steel Pipe Group (CSPG) Co., Ltd

Cangzhou Steel Pipe Group (CSPG) Co., Ltd. is a large-sized, key metallurgic enterprise of Hebei Province in North China, whose history dates back to 1994. CSPG currently em/paces six member companies with products varying from SSAW, LSAW, ERW, seamless steel pipes to 3PE pipes, galvanized pipes, casing pipes, etc. A Joint-stock corporation, CSPG occupies an area of 600,000 square meters with a total asset of $530 million.



Specialized in the production of straight welded pipe spiral pipe galvanized pipe 3PE/3PP/FBE/TPEP internal and external epoxy powder internal and external epoxy resin cement mortar two cloth three oil buried pipeline IPN8710 non-toxic drinking water internal and external plastic coated lining plastic and other anti-corrosion pipe fittings for oil and gas pipeline water conservancy projects



Executive standard :DIN30670 DIN30678 CSA Z245 AFNOR nf49-710/711 NACE rp0394/0490 AWWAC 210/C213GB/T9711 API 5L ISO 3183Material: Q235B/Q355BGR A GR B x42-x80 l245-l555

 

Business scope: 21.3mm-3620mmLSAW submerged arc welded pipe 325-2020mmERW straight welded pipe 6mm-711mmSMLS seamless tube 10-1120mmSSAW spiral steel tube 219-3620mmDemand for quality suppliers and partners



Product name

Three PE anti-corrosive pipe

Length

6m-12m ,or by customer's requirements

Laid way

Buried

Application

Water,oil gas, Coal to gas

Production Standard 

The national standard GB/T23257-2009

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            Specification of Thickness of Anti-corrosive Coating

DN(mm)

Epoxy powder

(μm)

Adhesive layer(μm)

Minimum thickness on the coating(mm)

Commonlevel(G)

Strengthen level(S)

DN≤100

120

170

1.8

2.5

100<DN250

2.0

2.7

250<DN<500

2.2

2.9

500≤DN<800

2.5

3.2

DN≥800

3.0

3.7

 

 Indexes of anti-corrosive layer

            Item

Indexes

Two layer

Three layer

Peel strength(N/cm)

(20±10℃)/(50±5℃)

70

35

100(cohesive failure)

70 (cohesive failure)

Cathodic disbonding

(65℃,48h)/(mm)

15

6

Cathodic disbonding(the highest temperature,30d)/(mm)

25

15

Impact strength(J/mm)

8

Counter bending(-20℃,2.5°)

No crack

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Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline

 

Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline  
 
 Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline
 
Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline
Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline
Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline

 Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline

 

Xingbang Custom Epoxy coated API 5L  steel tube three PE anticorrosion pipeline