GI pipe is zinc-coated steel pipe. Order it by the required standard, nominal size, outside diameter, wall series, end connection and coating specification. A DN label alone does not identify wall thickness or pressure capacity. For Qatar and UAE projects, confirm the full pipe-and-fitting specification and current supplier quotation before comparing prices.
GI pipe sizes and wall thickness
The reference dimensions below cover selected EN 10255 medium and heavy series. They were checked against the original manufacturer's technical delivery datasheet. They describe a reference product specification, not confirmed Aamtron stock. DN is a nominal designation; the actual internal bore is the specified outside diameter minus twice the specified wall thickness.
| Nominal inch | DN | OD mm | Medium wall mm | Heavy wall mm |
|---|---|---|---|---|
| 1/2 | 15 | 21.3 | 2.6 | 3.2 |
| 3/4 | 20 | 26.9 | 2.6 | 3.2 |
| 1 | 25 | 33.7 | 3.2 | 4.0 |
| 1 1/4 | 32 | 42.4 | 3.2 | 4.0 |
| 1 1/2 | 40 | 48.3 | 3.2 | 4.0 |
| 2 | 50 | 60.3 | 3.6 | 4.5 |
| 2 1/2 | 65 | 76.1 | 3.6 | 4.5 |
| 3 | 80 | 88.9 | 4.0 | 5.0 |
| 4 | 100 | 114.3 | 4.5 | 5.4 |
| 5 | 125 | 139.7 | 5.0 | 5.4 |
| 6 | 150 | 165.1 | 5.0 | 5.4 |
For a light-series order, specify the required L, L1 or L2 series and obtain the manufacturer’s verified dimensional schedule. Confirm the standard edition, tolerances and project requirements against the mill documentation before procurement.
Pipe weight in kilograms per metre
The weight table shows calculated theoretical bare-steel mass. It uses steel density of 7,850 kg/m³ and the geometry of a hollow cylinder: kg/m = π × wall thickness × (outside diameter − wall thickness) × 7,850 ÷ 1,000,000, with dimensions in millimetres. These calculations exclude zinc coating, threaded ends, couplings and manufacturing tolerance.
| DN | Medium bare steel kg/m | Heavy bare steel kg/m |
|---|---|---|
| 15 | 1.199 | 1.428 |
| 20 | 1.558 | 1.870 |
| 25 | 2.407 | 2.930 |
| 32 | 3.094 | 3.788 |
| 40 | 3.559 | 4.370 |
| 50 | 5.034 | 6.193 |
| 65 | 6.437 | 7.946 |
| 80 | 8.375 | 10.346 |
| 100 | 12.185 | 14.502 |
| 125 | 16.610 | 17.885 |
| 150 | 19.742 | 21.268 |
Use the mill's actual delivered mass basis when comparing freight or purchasing tonnage. A six-metre tube's theoretical bare mass can be estimated by multiplying the table value by six. That calculation does not establish the shipment's certified weight, the coating mass or the allowable working pressure.
Current price enquiries in Qatar and the UAE
Compare quotations for the same pipe series, finish, length and end condition. A price for a plain-end medium tube cannot be compared directly with a threaded heavy tube supplied with sockets. Ask whether cutting, threading, fittings, transport, unloading, tax and installation are included. Quote the delivery location and the required date.
Request an itemized supply quotation in QAR for Qatar or AED for the UAE, with the date, quantity, tax, transport and quotation validity stated. This reference guide does not list current selling prices.
An installed piping price also depends on fittings, valves, supports, work height, route access, shutdown arrangements, testing and handover documentation. Use a measured scope for an installation quotation. Keep supply-only prices distinct from installed costs and state the quotation validity period.
EN 10255 BS 1387 and ASTM A53
BS 1387 is a legacy withdrawn specification. EN 10255 and ASTM A53/A53M have their own scopes, classifications and dimensional requirements. Confirm which specification and edition the project requires. Do not describe EN medium and heavy classes as universal equivalents of Schedule 40 and Schedule 80. Matching nominal size does not establish matching outside diameter or wall.
ASTM A53/A53M covers black and hot-dipped zinc-coated welded and seamless steel pipe. Compliance with a pipe material specification does not by itself establish the pressure rating of an assembled threaded or welded system. Obtain certificates for the delivered material and check the design, joints, fittings, valves, seals, temperature and corrosion allowance as applicable.
GI pipe versus MS pipe
In ordinary commercial usage, GI refers to galvanized steel while MS often refers to ungalvanized mild steel. Galvanizing changes the surface protection; it does not remove the need to check the underlying grade, wall, connections and design requirements. Condensate, damaged coating, deposits and operating conditions affect a compressed-air installation.
Ask how cut ends, threaded joints, dissimilar metals and supports are treated. For a maintenance replacement, inspect the existing network rather than selecting solely from the original nominal size. Where internal deposits reduce the clear bore, a new hydraulic assessment may be needed.
GI versus aluminium for compressed air
A modular aluminium system can reduce on-site threading and make future changes easier, subject to the selected product's instructions and rating. GI may fit an existing steel installation or a project specification, but the work scope should include joint preparation, support requirements and internal cleanliness. Compare the complete installed system and its intended duty.
Neither material guarantees clean air or an ISO 8573-1 purity class by itself. Air treatment, drying, condensate management, installation cleanliness and measurement at the specified point of use all matter. Use the air pipe size calculator for a preliminary bore estimate, then verify the actual selected product data.
Frequently asked questions
What does GI mean?
GI is the common trade term for galvanized steel pipe. Confirm the actual steel specification and zinc-coating requirements in the order.
Is DN the internal diameter?
No. DN is nominal. Calculate a specified reference bore from the outside diameter and wall, then check tolerances and the actual product documentation.
Is medium pipe the same as Schedule 40?
No. EN 10255 medium and ASTM dimensional schedules belong to different specifications. Compare exact dimensions and required properties.
How much does a six-metre pipe weigh?
Multiply a verified per-metre mass by six, while keeping coating, couplings, end condition and manufacturing tolerance on the same basis.
Does the table give delivered galvanized weight?
No. The table contains geometric theoretical bare-steel mass. Obtain the delivered galvanized mass basis from the mill.
What is the current GI pipe price?
A current written quotation is required for the specified pipe, quantity and delivery location. Ask for the quotation date, validity and inclusions so that prices can be compared on the same basis.
Can GI pipe be used for compressed air?
Its suitability depends on the complete design, material, joints, fittings, internal condition and operating requirements. Confirm the selected system for the actual duty.
Can I assume a 40 bar rating?
No. A general material name or schedule label does not establish a complete system's allowable pressure and temperature.
Which light series should I order?
Specify the required series and edition explicitly. The L, L1 and L2 details need verification from the actual product documentation.
What should I send for a quotation?
Send sizes, standard, wall series, quantity, lengths, end condition, coating, fittings, delivery area and whether installation and testing are required.
For a measured supply or installation enquiry, see GI pipe supply and installation in Qatar and the UAE. For a factory air network, see compressed air piping contractors in Qatar or the UAE piping services page.
Reference source
Outside diameters and medium/heavy walls were checked against Table 2 on page 1 of the Tata Steel Install Plus technical delivery datasheet. The mass values here are independently calculated bare-steel values, rather than delivered galvanized weights. Reference data reviewed 31 October 2026.