Hot Dip Galvanized Pipe

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.

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Category: Weld steel pipe Tag: Galvanized pipe

Description

Hot-dip galvanizing (HDG) is the process of coating iron, steel or ferrous materials with a layer of zinc. This done by passing the metal through molten zinc at a temperature of 860°F (460°C) to form zinc carbonate (ZNC03). Zinc carbonate is a strong material that protects steel and can prevent corrosion in many circumstances. Hot-dip galvanizing can be carried out cheaply and in large batches.

Hot dipped galvanized with PE coating welded steel pipes

Galvanizing is one of the most widely used to methods for protecting metal from corrosion. It involves applying a thin coating of zinc to a thicker base metal, helping to shield it from the surrounding environment. The next time you are in your car, take a look at the street signs and lamp posts you pass. A large number of them will have a mute, silver color on them. That “silver” is actually the coating of zinc.

Thus, PE Coated Steel Pipes have been highly acclaimed even under severe environments such as areas of extreme cold, desert regions and under the sea.

Hot-dip galvanizing involves three main steps

Preparation: The galvanizing reaction will only occur on a chemically clean surface, so the first step of the process involves removing contamination. First, the metal is degreased using a caustic solution and then dipped in hydrochloric acid to remove rust, mill scale, welding slag, paint and grease. This followed by a rinse and a dip in a flux solution, which is usually about 30 percent zinc ammonium chloride.

Galvanizing: When the clean iron or steel component is dipped into the molten zinc (at 842°F (450°C)), zinc-iron alloy layers form as a result of a metallurgical reaction between the iron and zinc. When the material is pulled from the galvanizing bath, a layer of molten zinc is present on top of the alloy layer. When it cools, it has the bright, shiny appearance associated with galvanized products.

Inspection: After galvanizing, the coated materials are inspected for coating thickness and coating appearance. A variety of simple physical and laboratory tests may be performed to determine thickness, uniformity, adherence and appearance of the zinc coating.

Quite simply, galvanizing a metal gives it anti-corrosion properties. Without the protective zinc coating, the metal would remain exposed to the elements and potentially oxidize and corrode much faster. Galvanized Steel is a cost effective alternative to using materials such as austenitic stainless steel or aluminum in order to prevent corrosion.

How Does It Work?

Galvanizing can protect metal is a number of ways. Firstly, it creates a protective coating that shields the metal from the surrounding environment. The layer of zinc prevents water and moisture and other elements in the air from corroding the steel underneath. Should the zinc coating be scratched deep enough, the metal would become exposed and susceptible to corrosion.

Galvanizing can also protect metal through a process called “galvanic corrosion”. Galvanic corrosion occurs when two metals of a different electrochemical make up are placed into contact with one another with an electrolyte present, such as salty water. Depending on the atomic structure of the two metals, one metal is the anode and the other is the cathode. The anode corrodes more rapidly than it would by itself and the cathode corrodes at a slower pace than it would by itself. The reason zinc is used for galvanizing is because it has an affinity towards being the anode when in contact with many different types of metals. Since the zinc coating in contact with the base metal is usually the anode, it slows the corrosion of the base metal, or the cathode.

The difference between hot dip galvanizing and cold galvanizing

1. Essential difference

Cold galvanizing, also known as electro-galvanizing, is to use electrolytic equipment to deoil and pickle the workpiece into a solution of acid salt, and connect the negative electrode of the point solution equipment, and place a zinc plate on the opposite side of the workpiece to connect to the electrolytic equipment. The positive electrode, turn on the power supply, and use the current to move from the positive electrode to the negative electrode, which will deposit a layer of zinc on the workpiece.

Hot-dip galvanizing (galvanized steel tube) is also called hot-dip galvanizing. It is a method of immersing steel hooks in molten zinc to obtain a metal coating, you can bring it up.

2. Principle difference

Cold galvanizing uses chemical principles to separate zinc alloys into zinc ions, which are attached to the surface of steel. Generally, the zinc layer is thin, and steel is easily corroded in general environments. Generally, cold galvanizing is used for anti-corrosion of various steel products and structures. The amount of galvanizing of cold galvanizing is very small, only 10-50g per square meter.

As we all know, the mechanism of zinc’s resistance to atmospheric corrosion includes mechanical protection and electrochemical protection. Under atmospheric corrosion conditions, the surface of the zinc layer has ZnO, Zn(OH)2 and basic zinc carbonate protective films, which slow down the corrosion of zinc to a certain extent. The protective film (also known as white rust) is damaged and a new layer is formed. When the zinc layer is seriously damaged and endangers the iron matrix, zinc produces electrochemical protection for the matrix. The standard potential of zinc is -0.76V, and the standard potential of iron is -0.44V. When zinc and iron form a microbattery, zinc is dissolved as an anode. , the iron is protected as a cathode. The formation process of the hot-dip galvanized layer is the process of forming an iron-zinc alloy between the iron matrix and the outer pure zinc layer. The iron-zinc alloy layer is formed on the surface of the workpiece during hot-dip plating, which can make the iron and pure zinc layer very close. good combination.

3. Appearance difference

Hot-dip galvanized looks rougher in appearance, while cold-dip galvanized is brighter and smoother.

The appearance of hot-dip galvanizing is not as delicate and bright as cold galvanizing, but the thickness of the zinc layer is dozens of times that of cold galvanizing. The anti-corrosion performance is that the electroplating hot-dip galvanized layer is thick, and the surface of the coating generally has sequins that can be recognized by the naked eye, and the surface can be touched by hand. It feels a certain roughness and has a bright silver appearance. When the temperature of hot-dip galvanizing production is too high, the appearance is mainly gray, and the small pieces of the zinc-iron alloy layer will fall off when knocked.

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

Zinc thickness for cold galvanized steel pipe

Cold galvanized steel pipe zinc thickness is 5-15 μm, the layer is dense, and there is no inclusion with organic matter.

Cold galvanization technology is no longer recommend for pipe products.

For more thinner zinc layer reason, countries of the world have gradually forbidding the cold galvanized steel pipe as water pipe and coal gas pipe. But due to cold galvanizing processing have smooth appearance of surface, it always used in manufacturing small pieces which requiring precise plating. Such as screws, Machinery manufacturing, electronics, precision instruments, chemicals, light industry, transportation, weapons, aerospace, atomic energy, etc., in the national economy has great significance.

What’s the difference between Pre – galvanized and Hot- galvanized steel pipe?

Galvanized steel pipes: one is pregalvanized steel pipe, short for GI pipe; The other is hot dipped galvanized steel pipe. For hot dipped galvanized steel pipe, it includes two technologies: galvanized by zinc blowing machine and galvanized by zinc pool.

Hot dip galvanizing pipe is that a Pipe was dipped into the bath after fabrication.Thickness by this method will reach minimum up to 45 µm and the thickness of the zinc coating is influenced by a number of factors, including the surface of the steel, the time the steel is dipped in the bath, the composition of the steel as well as the steel’s size and thickness.

One advantage of hot dip galvanizing is that the entire part is covered including the edges, welds, etc. giving it an all-round corrosion protection. The end product can be used outdoors in all different weather conditions. It is the most popular galvanizing method and is widely used in the construction industry.

Pre-galvanizing pipe, also known as mill galvanized pipe, hot dip mill galvanized or continuous hot dip galvanized.Pre-galvanized steel pipe refers to pipe which was galvanized while in sheet format, thus prior to further manufacturing. After the sheet is sent through the mill to be galvanized it is cut to size and recoiled.the pipe thickness will be minimum 12 µm.

One of the advantages which pre-galvanized steel has over hot dip galvanized steel is that it has a better appearance.pre-galvanized materials are used for a wide variety of products including conduit, lip and open channels.

How to distinguish the hot-dip galvanized steel pipe and electro galvanized steel pipe?

Galvanized pipes are the pipes that a layer of protective zinc coating to pipe in order to prevent premature rust and corrosion. There are several different processes for galvanizing steel pipe,Hot-Dip Galvanizing and Electrogalvanizing are the most commonly used ways for steel pipes.To distinguish the Galvanized steel pipe and Electrogalvanized steel pipe,you should understand the manufacturing process of them.

Hot-Dip Galvanizing

As the name implies, this method involves dipping the base metal into a molten pool of zinc. First, the base metal must be cleaned either mechanically, chemically, or both to assure a quality bond can be made between the base metal and the zinc coating. Once cleaned, the base metal is then fluxed to rid it of any residual oxides that might remain after the cleaning process. The base metal is then dipped into a liquid bath of heated zinc and a metallurgical bond is formed.

Electro-galvanizing

Electrogralvanizing utilizes an electrical current in an electrolyte solution to transfer zinc ions onto the base metal. This involves electrically reducing positively charged zinc ions to zinc metal which are then deposited on the positively charged material. Grain refiners can also be added which helps to ensure a smooth zinc coating on the steel.

The main difference between Galvanized pipes and Electrogalvanized steel pipe

1.The zinc layer

The thickness of hot dip galvanized zinc layer can achieved more than 50 microns, the maximum can reach 100 microns.Electro-galvanized zinc layer generally in the 3 to 5 microns, special requirements can also reach 7 to 8 microns.

2.Appearance

hot dip galvanization has dull, unpleasant finish.However, Electro-galvanization comes with excellent finish.

3.Life

Hot dip galvanized pipe is known to have very high life averaging between 20 to 50 years. But, lectro-galvanization has very low life, ranging from several months to some years only.

4.Costs

The cost is said to increase proportionately with higher coating thickness. hence the hot dip galvanized pipe with normal coat thickness about 40% expensive than electro-galvanizing pipe.

Standard

Welded pipes specification and size

Product Name	Executive Standard	Dimension (mm)	Steel Code / Steel Grade
Electric-Resistance-Welded Steel Pipes	ASTM A135	42.2-114.3 x 2.11-2.63	A
Electric-Resistance-Welded Carbon Steel and Carbon-Manganese Steel Boiler and Superheater Tubes	ASTM A178	42.2-114.3 x 2.11-2.63	A, C,D
ERW and Hot-dip Galvanized Steel Pipes	ASTM A53	21.3-273 x 2.11-12.7	A, B
Pipes for Piling Usage	ASTM A252	219.1-508 x 3.6-12.7	Gr2, Gr3
Tubes for General Structural Purpose	ASTM A500	21.3-273 x 2.11-12.7	Carbon Steel
Square Pipes for General Structural Purpose	ASTM A500	25 x 25-160 x 160 x 1.2-8.0	Carbon Steel
Mechanical tubing	ASTM A513	21.3-273 x 2.11-12.7	carbon and alloy steel
Screwed and Socketed Steel Tubes	BS 1387	21.4-113.9 x 2-3.6	Carbon Steel
Scaffolding Pipes	EN 39	48.3 x 3.2-4	Carbon Steel
Carbon Steel Tubes for General Structure Purpose	JIS G3444	21.7-216.3 x 2.0-6.0	Carbon Steel
Carbon Steel Tubes for Machine Structure Purpose	JIS G3445	15-76 x 0.7-3.0	STKM11A, STKM13A
Carbon Steel Pipes for Ordinary Piping	JIS G3452	21.9-216.3 x 2.8-5.8	Carbon Steel
Carbon Steel Pipes for Pressure Service	JIS G3454	21.7-216.3 x 2.8-7.1	Carbon Steel
Carbon Steel Rigid Steel Conduits	JIS G8305	21-113.4 x 1.2-3.5	G16-G104, C19-C75, E19-E75
Carbon Steel Rectangular Pipes for General Structure	JIS G3466	16 x 16-150 x 150 x 0.7-6	Carbon Steel

Coating

Pipeline coating is the most consistent and successful solution for protecting ERW pipes from corrosion, from moisture, other harmful chemicals.

Anti-corrosion steel pipe is processed through the preservation process, which can effectively prevent or slow down the process in the transport and use of chemical or electrochemical corrosion reaction of steel pipe.

Therefore pipe anti-corrosion layer is an important barrier to prevent soil erosion. A well-known foreign scholar put forward” 3PE france protective layer”, so far, anti-corrosion methods is widely used.

Coated pipes offer high resistance to corrosion on pipes and provide many benefits such as:

1. Increased Flow Capacity – A coating on pipes helps provide a smoother surface thus improving gas and liquid flow within pipes.

2. Reduced Cost – The pipeline coating increases the pipes durability so they can be deployed with minimum maintenance cost even in the harshest environments.

3. Lower energy usage – Various studies have shown that pipelines that are internally coated use less energy for pumping and compression of products through pipes. This helps in increased saving over time.

4. Clean delivery of products – The inhibitors used for the protection products can also be minimized by the use of coated pipes for delivery of products.

Thus, coating of pipelines can help you in reducing your maintenance cost and at the same time providing a corrosion free reliable protection.

Basic functions of erw pipe coating

making the surface of ERW steel pipes free from electrochemical corrosion of the soil medium, the basic physics of bacterial corrosion protection.
resisting the move of the soil medium creep stress, static stress and abrasion force method and structure of the basic machinery protection.

The basic principles of urban gas pipeline coating selection:

good insulating and mechanical properties;
good resistance to cathodic disbondment performance;
good resistance to water, gas permeability;
good chemical resistance soaking performance and anti-aging properties;
resistance to low temperature and high temperature performance;
easy mending and mending;
at reasonable prices.

Types of coating:

Coating Specifications

2.1.External Coating

2.1.1 External Epoxy Coating

API RP 5L2 Recommended Practice for Internal Coating of Line Pipe for Non-Corrosive Gas Transmission Service.
CAN/CSA-Z245.20 Standard for External Fusion Bond Epoxy Coating for Steel Pipe
AS 3862 Standard Specification for External Fusion-Bonded Epoxy Coating for Steel Pipes
AWWA C210 Standard for Liquid-Epoxy Coating Systems for the Interior and Exterior of Steel Water Pipelines
AWWA C213 Standard for Fusion Bonded Epoxy Coating for the Interior and Exterior of Steel Water Pipelines.
DEP 31.40.30.32-Gen TECHNICAL SPECIFICATION FOR EXTERNAL FUSION-BONDED EPOXY POWDER COATINGFOR LINE PIPE
NFA 49-710 Standard Specification for External FBE layered Coating
ISO 21809-2:2007, Petroleum and natural gas industries-External coatings for buried or submerged pipelines used in pipeline transportation systems-Part 2:
Fusion-bonded epoxy coatings
NACE RP0394 – National Association of Corrosion Engineers Standard Recommended Practice, Application, Performance, and Quality Control of Plant Applied, Fusion Bonded Epoxy External Pipe Coating.
NACPA 12-78 – National Association of Pipe Coating Applicators External Application Procedure for Plant Applied fusion Bonded Epoxy (FBE) to Steel Pipe.
SAES-H-002 Internal and External Coatings for Steel Pipelines and Piping
09-SAMSS-089 Shop-Applied External FBE Coating
09-SAMSS-091 Shop-Applied Internal FBE Coatings

2.1.2 Polyethylene Coating

CAN/CSA Z245.21 External Polyethylene Coating for Pipe
DIN 30670 Polyethylene Sheathing of Steel Tubes and of Steel Shaped Fittings
NFA 49-710 External Three-Layer Polyethylene Based Coating, Application by Extrusion
DNV-RP-F106 Factory Applied External Pipeline Coatings For Corrosion Control
AS/NZS 1518 External Extruded High-Density Polyethylene Coating System for Pipes
ISO 21809-1 Petroleum and natural gas industries — External coatings for buried or submerged pipelines used in pipeline transportation systems – Part 1: Polyolefin coatings (3- layer PE and 3- layer PP)
ISO 21809-4:2009, Petroleum and natural gas industries -External coatings for buried or submerged pipelines used in pipeline transportation systems-Part 4: Polyethylene Coatings (2-layer PE)
DEP 31.40.30.31-Gen. TECHNICAL SPECIFICATION FOR EXTERNAL POLYETHYLENE AND POLYPROPYLENE COATING FOR LINE PIPE
IPS-G-TP-335 Material and Construction Standard for Three Layer Polyethylene Coating System
NFA 49-710 External 3 layer Polyethylene Coating
PETROBRAS’ ET-200.03 Engineering Specification (“Piping Materials for Production and Process Facilities”) for using low density linear polyethylene in carbon steel piping, as to appendix 13 of such specification.
09-SAMSS-113 External Renovation Coating for Buried Pipelines and Piping (APCS-113)
UNI 9099-DIN 30670 Polyethylene Coating Applied by Extrusion

2.1.3 Polypropylene Coating

DIN30678 Polypropylene Sheathing of Steel Tubes and of Steel Shaped Fittings
EN 10286 Steel tubes and fittings for onshore and offshore pipelines –External three layer extruded polypropylene based coatings.
NFA 49-711 External Three-Layer Polypropylene Based Coating, Application by Extrusion
09-SAMSS-114 Shop-Applied Extruded, Three-Layer Polypropylene External Coatings for Line Pipe

2.1.4 Polyurethane Coating

AWWA C222-99: Polyurethane Coatings for the Interior and Exterior of Steel Water Pipe and Fittings
BS 5493- Polyurethane Coating
DIN 30677.2 polyurethane Insulation of the fittings
EN 10290- External Liquid Applied Polyurethane Coatings

2.1.5 Polyolefin Coating

AWWA C225-03: Fused Polyolefin Coating Systems for the Exterior of Steel Water Pipelines
AWWA C215-99: Extruded Polyolefin Coatings for the Exterior of Steel Water Pipelines
AWWA C216-00 Standard for Heat-Shrinkable Cross-Linked Polyolefin Coatings for the Exterior of Special Sections, Connections, and Fitting for the Steel Water Pipelines
AWWA C224 – 01: Two-layer Nylon-11 Based Polyamide Coating System for Interior and Exterior of Steel Water Pipe and Fittings
AWWA C225 – 03: Fused Polyolefin Coating Systems for the Exterior of Steel Water Pipelines

2.1.6 Tape Coating

ISO 21809-3:2008, Petroleum and natural gas industries-External coatings for buried or submerged pipelines used in pipeline transportation systems-Part 3: Field joint coatings
AWWA C209-00: Standard for Cold-Applied Tape Coatings for the Exterior of Special Sections, Connections, and Fittings for Steel Water Pipelines
AWWA C214-00 Standard for Tape Coating Systems for the Exterior of the Steel Water Pipelines
AWWA C217-99 Standard for Cold-Applied Petrolatum Tape and Petroleum Wax Tape Coatings for the Exterior for Special Sections, Connections, and Fittings for Buried/Submerged Steel Water Pipelines
AWWA C218-02 Standard for Coating the Exterior of Aboveground Steel Water Pipelines and Fittings
AWWA C224-01: Two-layer Nylon-11 Based Polyamide Coating System for Interior and Exterior of Steel Water Pipe and Fittings
EN 12068 – DIN 30672 STANDARD-POLYETHYLENE SELF ADHESIVE TAPES

2.1.7 Bitumen Coating

DIN 30673 Bitumen coatings and linings for steel pipes, fittings and vessels.
BS 534

2.1.8 Coal-Tar Enamel Coating

AWWA C-203 Coal-Tar Protective Coatings and Linings for Steel Water Pipelines-Enamel and Tape-Hot-Applied
AWWA C205 Cement Mortar Protective Lining and Coating for Steel Water Pipe – 4 inch (100 mm) and Larger- Shop Applied
BS 534

2.1.9 Concrete Weighted Coating

DNV-OS-F101 Submarine Pipeline System
ASTM C171 Specification for Sheet Material for Coating Concrete
BS EN 12620 Aggregates for Concrete
ISO 21809-5:2009, Petroleum and natural gas industries -External coatings for buried or submerged pipelines used in pipeline transportation systems – Part

5:External concrete coating.

ASTM C42 Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
ASTM C642 Standard Test Method for Specific Gravity, Absorption and Voids in Hardened Concrete
ASTM C87 Standard Test Method for Effect of Impurities in Fine Aggregate on Strength of Mortar BS 1881 Methods of Testing Concrete
BS 3148 Methods of Test for Water for Making Concrete
BS 4482 Hard Drawn Mild Steel Wire for the Reinforcement of Concrete
BS 4483 Specification for Steel Fabric for the Reinforcement of Concrete
BS 4449 Specification for Carbon Steel Bars for Reinforcement of Concrete
ISO 4012 Determination of Compressive Strength of Test Specimen

2.1.10 Marine Coating

EN ISO 12944:1998 – Paints & Varnishes – Corrosion Protection of Steel Structures by protective paint system (parts 1 – 8)
ISO 20340:2009 Paints and varnishes – Performance requirements for protective paint systems for offshore and related structures
ISO 15741 Paints and varnishes-Friction-reduction coatings for the interior of on- and offshore pipelines for non-corrosive gases

2.1.11 Other specification

British Gas BGC/PS/CM1,
BGC/PWS/CM2
GAZ de France R 09
NACE RP 0181
NF A 49-706
TS 5140
TS 5139

2.2. Lining

2.2.1 Epoxy Lining

AWWA C210: Liquid-Epoxy Coating Systems for the Interior and Exterior of Steel Water Pipelines
API RP512 or NFA 49-709 Internal can be epoxy 80 microns
TS EN 10289
NFA 49708 Recommended Practice for Internal Coating of Line Pipe

2.2.2 Bitumen Lining

DIN 30673 Bitumen coatings and linings for steel pipes, fittings and vessels
UNI-ISO 5256/87 STANDARD-BITUMEN COATING
BS 534

2.2.3 Cement Mortar Lining

AS/NZS 1516 Cement Mortar Lining of Pipelines In Situ
AWWA C203-02: Coal-Tar Protective Coatings & Linings for Steel Water Pipelines, Enamel & Tape, Hot-pap. (Incl. add. C203a-99)
AWWA C205-00: Cement-Mortar Protective Lining and Coating for Steel Water Pipe- 4 In. (100 mm) and Larger-Shop application
AWWA C602 Standard for Cement-Mortar Lining of Water Pipelines – 4 inch (100 mm) and Larger – In Place
BS 534

2.2.4 Shop Cement Lined Piping

AWWA C205,C104,C602
DIN 2614
British Standard BS 534
British Petroleum GS 106-1
Shell DEP 30.48.30.31-Gen.
Saudi Aramco 01-SAMSS-005
KNPC ENG STD 87C1
API RP 10E

Pipe Coating Products

Fusion Bonded Epoxy – Fusion Bond Epoxy is a powder epoxy thermosetting coating applied for anticorrosion protection to steel pipelines. The pipe is first blast cleaned and heated. Then epoxy powder is spray applied by electrostatic guns to melt and form a uniform layer that hardens within a minute from application. Utilizing industry accepted materials supplied by manufacturers such as 3M, DuPont, and Valspar, the facility can apply FBE in a wide range of thickness to cost effectively meet any project specifications.
Fusion Bonded Epoxy with Abrasion Resistance Overcoating (FBE/ARO) – Utilizing two completely separate powder systems, the facility can produce FBE with an ARO at unprecedented processing speeds using industry accepted materials such as 3M 6352, DuPont 7-2610, and Lilly 2040.
Fusion Bonded Epoxy with High Temperature Resistant Overcoating – Utilizing two completely separate powder systems, the facility can produce FBE with a high operating temperature resistant overcoating such as DuPont’s Nap-Gard Gold and 3M’s 6258.
Fusion Bonded Epoxy with Zap-Wrap Overcoating – The facility is capable of processing line pipe with connections and of applying the Zap-Wrap abrasion resistance overcoating to the ends of each pipe.

Three Layer Polyethylene (3LPE)

To improve anticorrosion performance and adhesion, an additional layer of epoxy primer is sprayed onto pipe surfaces prior to the adhesive layer and Polyethylene top layer application. Three Layer Polyethylene is suitable for service temperatures from 60°C to 80°C (85°C peaks). Typical coating thickness is from 1-2 mm to 3-5 mm.

Three Layer Polypropylene (3LPP)

If a wider service temperature range and high stiffness is required, adhesive and top layers, applied over primer layer, are based on polypropylene instead of polyethylene. Three Layer Polypropylene is suitable for service temperatures up to 135 °C (140°C peaks). Typical coating thickness is from 1-2 mm to 3-5 mm.

Three Layer Polypropylene and Polyethylene

Three Layer applications involve a thermoplastic coating applied to steel pipelines as a form of anticorrosion protection. This mechanical resistance is appropriate when the risk of particularly severe coating damages exist. The Three Layer process involved several steps. First, the pipe surface is blast cleaned to remove any external residue from the mill or storage. It is then heated and sprayed with a Fusion Bond Epoxy (FBE) primer followed by the application of an adhesive copolymer and polyolefin polymers that are wrap extruded, one over the other.

Field applied products

3M: SK 134, SK6233, SK6352 Toughkote, SK 314, SK 323, SK 206N, SK 226N, SK 6251 DualKote SK-6171, SK 206P, SK226P,
3M Internal Coatings: Coupon EP2306HP
DuPont: 7-2500, 7-2501, 7-2502, 7-2508, 7-2514, 7-2803, 7-2504 Nap Gard Gold 7-2504, Nap Rock: 7-2610, 7-2617 FBE Powders
DuPont: Repair Kits; 7-1631, 7-1677, 7-1862, 7-1851
DuPont Internal Coatings: 7-0008, 7-0010, 7-0014, 7-0009SGR, 7-0009LGR, 7-2530, 7-2534, 7-2509
Akzo Nobel: FBE – Fusion Bond Epoxy
Internline 876 Seal Coat
Hampel: 85448,97840
Denso: 7200, 7900 High Service Temperature Coatings
Internal Liquid Epoxy: Powercrete Superflow

Delivery

FAQs

Advantage of ERW pipe

The alloy content of the coil is often lower than similar grades of steel plate, improving the weldability of the spiral welded pipe. Due to the rolling direction of spiral welded pipe coil is not perpendicular to the pipe axis direction, the crack resistance of the spiral welded pipe materials.

Inquiry

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FAQ

Q: How long is your delivery time?
A: The delivery time of customized products is generally 25 35 days, and non customized products are generally shipped within 24 hours after payment.

Q: Do you provide samples? Is it free?
A: If the value of the sample is low, we will provide it for free, but the freight needs to be paid by the customer. But for some high value samples, we need to charge a fee.

Q: What are your payment terms?
A: T/T 30% as the deposit,The balance payment is paid in full before shipment

Q: What is the packaging and transportation form?
A: Non steaming wooden box and iron frame packaging. Special packaging is available according to customer needs. The transportation is mainly by sea.

Q: What is your minimum order quantity?
A: There is no minimum order quantity requirement. Customized products are tailor made according to the drawings provided by the customer.