Galvanized Seamless Rectangle Steel Pipe
Jointless hollow section with a zinc coated surface in schedule wall thicknesses
Specifications
Seamless Steel Pipe, Steel Pipe
Seamless Steel Pipe in A53 A106 and A333 Grades
Hollow section pipe with no joint around it for pressure and low temperature service
Seamless steel pipe is a long pipe of steel with a hollow section and no joint around it, so there is no weld line to qualify or inspect. It is specified by pressure piping designers and mechanical contractors working in A53 Grade A and B, A106 Grade A and B, the A333 low temperature grades GR1 GR3 and GR6 and the European S355JR S355JO and 355J2 structural grades. Ordering across schedules from SCH5S through SCH160 and XS in one purchase removes the usual split between a thin wall instrument line supplier and a heavy wall process line supplier. Lengths are supplied 5.8m and 6m fixed, 12m fixed or 2-12m random so the cutting plan can follow the spool drawing.
- Product Name — Seamless Steel Pipe
- Also Known As — Seamless steel tube hollow section pipe
- Material — A53 Gr. A, Gr B, A106 GR.A GR.B, A333 GR1 GR3 GR6, S355JR, S355JO, 355J2
- Outside Diameter — 1/2 inch to 48 inch, from 21.3mm, or customized
- Thickness Schedules — SCH5S, SCH10S, SCH20S, SCH20, SCH30, STD, SCH40, SCH60, SCH80, SCH100, SCH140, SCH160, XS
Why It Is Specified
Key Benefits of Seamless Steel Pipe
No Weld Seam to Qualify or Radiograph
The pipe is drawn with a hollow section and no joint around it. There is no longitudinal seam to run nondestructive testing against or to justify in a pressure calculation.
Full Schedule Ladder From SCH5S to SCH160
SCH5S, SCH10S, SCH20S, SCH20, SCH30, STD, SCH40, SCH60, SCH80, SCH100, SCH140, SCH160 and XS are all available. One supplier covers the instrument tubing and the heavy wall header on the same line item.
Low Temperature Grades Held Alongside Standard Ones
A333 GR1 GR3 and GR6 sit next to A53 and A106 in the grade list, so a cryogenic or cold climate line does not have to be sourced separately.
Four Length Options Against the Spool List
5.8m and 6m fixed, 12m fixed and 2-12m random are all offered. Choosing the right length before shipment cuts the offcut left in the fabrication shop.
Corrosion Protection Applied Before Loading
Black painted, galvanized, natural, anticorrosive 3PE coated and polyurethane foam insulated finishes are applied at the mill so buried or insulated line pipe arrives ready to install.
Wall Thickness Down to 1.65mm and Up to 80mm
The same grade family spans 1.65mm to 80mm wall, which means a small bore drain and a heavy wall manifold can share one material certificate lineage.
Problems It Solves
What This Material Removes From Your Process
Weld Seam Disallowed by the Piping Class
Many pressure piping classes will not accept a welded pipe. Seamless pipe has a hollow section and no joint around it, which satisfies the class without a deviation request.
Schedules Split Across Several Suppliers
Thin wall SCH5S and heavy wall SCH160 often come from different sources with different paperwork. Both ends of the ladder are quoted here on one order.
Random Lengths Wasting Shop Material
Random pipe forces the shop to cut around the drop. Choosing 5.8m, 6m or 12m fixed against the spool list reduces the offcut that gets scrapped.
Coating and Insulation Added After Delivery
Black paint, galvanizing, 3PE coating and polyurethane foam insulation applied before shipment remove a separate handling and curing step at site.
Cold Service Grades Treated as an Exception
A333 GR1 GR3 and GR6 are listed as standard material rather than a special enquiry, so a cold climate line is quoted with the rest of the package.
Application Scenarios
Where It Is Used
Process and Pressure Piping
A106 Grade A and B lines inside refineries chemical plants and process units where a seamless wall is written into the piping class.
Low Temperature and Cold Climate Lines
A333 GR1 GR3 and GR6 pipework for refrigeration, LPG handling and cold region service where impact toughness is specified.
Buried and Insulated Distribution Lines
Anticorrosive 3PE coated or polyurethane foam insulated pipe run underground or between plant buildings.
Structural and Mechanical Frames
S355JR S355JO and 355J2 sections used as structural members and machine frames where a round hollow section is wanted.
General Service and Utility Piping
A53 Grade A and B pipe in galvanized or black painted finish for water, air and utility distribution.
Fabrication Shop Spool Work
Prefabricated pipe spools cut from 12m fixed lengths and assembled with fittings before shipping to site.
Who It Is For
Buyers Who Specify This Product
- Piping engineers specifying A106 seamless line pipe against a plant piping class
- Mechanical contractors buying schedule pipe for process and utility spools
- Refrigeration and LPG contractors sourcing A333 low temperature grades
- Pipe fabrication shops ordering 12m fixed lengths to cut against a spool list
- Plant maintenance buyers replacing a corroded run and matching the original schedule
- Stockists carrying a schedule ladder from SCH5S to SCH160 for regional workshops
Technical Data
Specifications and Technical Features
Values below come from the product data published by Shandong Tianyu Metal Products. Confirm the exact grade and size against your order.
| Product Name | Seamless Steel Pipe |
|---|---|
| Also Known As | Seamless steel tube hollow section pipe |
| Material | A53 Gr. A, Gr B, A106 GR.A GR.B, A333 GR1 GR3 GR6, S355JR, S355JO, 355J2 |
| Outside Diameter | 1/2 inch to 48 inch, from 21.3mm, or customized |
| Thickness Schedules | SCH5S, SCH10S, SCH20S, SCH20, SCH30, STD, SCH40, SCH60, SCH80, SCH100, SCH140, SCH160, XS |
| Wall Thickness | 1.65mm - 80mm or customized |
| Length | 5.8m, 6m Fixed, 12m Fixed, 2-12m Random or customized |
| Surface Treatment | Black painted, galvanized, natural, anticorrosive 3PE coated, polyurethane foam insulation |
| Section Shape | Round hollow section |
| Place of Origin | China |
| Certificate | Mill test certificate |
Technical Features
- Hollow section with no joint around the circumference
- Material A53 Gr A and Gr B A106 GR.A and GR.B A333 GR1 GR3 GR6 S355JR S355JO 355J2
- Outside diameter from 1/2 inch to 48 inch starting at 21.3mm or customized
- Wall thickness schedules SCH5S SCH10S SCH20S SCH20 SCH30 STD SCH40 SCH60 SCH80 SCH100 SCH140 SCH160 and XS
- Wall thickness range 1.65mm to 80mm or customized
- Length 5.8m and 6m fixed 12m fixed or 2-12m random or customized
- Surface black painted galvanized natural anticorrosive 3PE coated or polyurethane foam insulated
Materials
- ASTM A53 Grade A and Grade B carbon steel
- ASTM A106 Grade A and Grade B seamless pressure pipe steel
- ASTM A333 low temperature grades GR1 GR3 and GR6
- European structural grades S355JR S355JO and 355J2
Certification
- ISO9001
- BV
- SGS
- RoHS
- Mill test certificate supplied with each shipment
Manufacturing
How It Is Made and Processed
Round billet heating and piercing to form the hollow shell
Hot rolling or elongating the shell to the ordered outside diameter
Sizing and straightening to the schedule wall thickness
Cutting to 5.8m 6m 12m fixed or 2-12m random length
End facing and deburring
Surface treatment in black paint galvanizing 3PE coating or polyurethane foam insulation
Bundling marking and loading for export
Quality Control
Checks Before It Ships
- Mill test certificate issued against the ordered A53 A106 A333 or S355 grade
- Outside diameter and wall thickness checked against the ordered schedule
- Straightness and end squareness inspected after cutting
- Surface finish confirmed for the ordered paint galvanizing or coating system
- Bundle count and length verified against the packing list before loading
Customization
What We Can Change on Your Order
- Outside diameter customized outside the standard 1/2 inch to 48 inch table
- Wall thickness customized between 1.65mm and 80mm where no schedule fits
- Cut length set to 5.8m 6m 12m fixed or 2-12m random against your spool list
- Surface finish chosen from black paint galvanizing natural 3PE or polyurethane foam insulation
- Grade selected from the A53 A106 A333 or S355 families named in your piping class
- Bevelled or plain ends to suit your welding method
Comparison
Seamless Steel Pipe Against the Alternatives
| ERW welded steel pipe | Seamless pipe has no joint around the circumference so there is no longitudinal seam to inspect or to derate in a pressure calculation. |
|---|---|
| Spiral welded steel pipe | Seamless is the route for pressure piping classes and for schedule wall sizes, while spiral covers very large diameters at lower pressure. |
| Stainless steel pipe | Carbon seamless pipe in A53 A106 or A333 costs less for lines where corrosion is handled by a 3PE coating or paint rather than by the alloy. |
| Standard carbon pipe for cold service | A333 GR1 GR3 and GR6 are held in the same grade list so a low temperature line does not need a separate supply chain. |
Use Guide
Specifying Handling and Welding Notes
- Give the schedule and the grade together because SCH40 in A106 and SCH40 in A333 carry different test requirements
- Pick 12m fixed lengths when the shop is cutting spools and 5.8m or 6m fixed when the material goes straight to site
- Order 2-12m random only when the application tolerates mixed lengths since it is the cheapest cut but leaves more drop
- Specify galvanizing or 3PE coating at order stage rather than arranging it locally after delivery
- Confirm the wall thickness in millimetres as well as the schedule when the size sits between 1.65mm and 80mm
- Ask for the mill test certificate with the shipment so the grade is traceable in the piping record
Questions Buyers Ask
Seamless Steel Pipe FAQ
Which wall thickness schedules can you supply?
SCH5S, SCH10S, SCH20S, SCH20, SCH30, STD, SCH40, SCH60, SCH80, SCH100, SCH140, SCH160 and XS. In millimetres that covers 1.65mm to 80mm, and a custom wall can be produced outside the schedule table.
What is the smallest pipe size you make?
The standard table starts at 1/2 inch, which is 21.3mm outside diameter. Sizes below that are treated as a customized enquiry.
Do you stock A333 low temperature grades?
A333 GR1, GR3 and GR6 are part of the standard material list alongside A53 and A106, so cold service lines are quoted with the rest of your package.
What length options are there and which one should I choose?
5.8m and 6m fixed, 12m fixed and 2-12m random. Fabrication shops normally take 12m fixed to cut against a spool list, while 5.8m suits container loading.
Can the pipe be delivered already galvanized or coated?
Yes. Black painted, galvanized, natural, anticorrosive 3PE coated and polyurethane foam insulated finishes are applied before shipment.
Can I substitute A53 Grade B for A106 Grade B?
That depends on your piping class and the design temperature. Send us the class sheet and the service conditions and we will confirm which of the listed grades is acceptable rather than swapping it on our own.
Is a mill test certificate included?
Yes. A mill test certificate is issued against the ordered grade and ships with the material.
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