GI Pipes

About GI Pipes

Hot-dip galvanized steel-pipe options that combine an applicable steel-tube standard with an ordered zinc-coating standard. Class, service suitability, coating acceptance and current supply must be confirmed for the RFQ.

Use this page as a product and specification reference. The quotation must state the exact material grade, dimensions, manufacturer, certification or document scope, inspection, quantity, price, current availability, freight, and proposed delivery timing for the specific RFQ.

Specification reference

Confirm the exact grade, dimensions, tolerance, test certificate, and current availability for your requirement before ordering.

Common applications

These are enquiry contexts, not universal approvals. The project design and governing specification must approve the exact product, grade, dimensions, and service conditions.

• Water Supply: Municipal and residential drinking water distribution.
• Fire Protection: Fire fighting sprinkler systems, standpipe installations.
• Construction: Scaffolding, fencing, greenhouse frames, handrails.
• Agriculture: Irrigation lines, pump risers, greenhouse structures.

Who should use GI pipe and where another product fits better

GI pipe suits above-ground water distribution, building plumbing, exposed utility lines, agricultural installations, fencing and selected fire-system work when the approved specification calls for galvanized steel. The zinc layer is a corrosion-control measure. It does not replace the steel-tube class, pressure design, joint specification or project inspection requirements. Write the substrate and coating requirements as separate PO lines.

A buyer should not select GI only because the service contains water. Buried lines, chemical service, high-temperature lines and fire networks can require a different material, coating system or wall class under the project design. Borewell casing also has its own product specification. Send the approved BOQ instead of translating every coated pipe item into IS 1239 GI.

• JJM and PWD contractors should preserve the exact NB, class, ISI-marking, coating and document wording from the tender schedule.
• Building plumbers should state threaded and coupled or plain ends before comparing bundles.
• Fire-system installers should match the approved riser, hydrant and branch-line specification rather than choosing by colour or coating alone.
• Borewell contractors should use the specified casing tube and thread form for the well design.
• Fabricators should protect the zinc layer during cutting, welding, storage and transport.

Potential source references

The quotation must identify the proposed manufacturer, current availability, inspection documents, and delivery basis for the specific RFQ.

• APL Apollo
• Tata Steel
• Jindal Star
• Surya Roshni
• Hi-Tech Pipes

Applicable standards and specifications

• IS 1239
• IS 3589

GI pipe class A / B / C selection table

IS 1239 Part 1 defines Light, Medium and Heavy dimensional series. The class is one input to a design check, not a standalone working-pressure rating or automatic permission for a particular service.

For a galvanized order, state the amended IS 4736 coating requirement and test scope. For water or fire-service work, follow the project specification and approving authority; this table does not replace hydraulic, surge, corrosion or code checks.

How Kanpur contractors specify a GI pipe order

Start the RFQ with the governing steel-tube standard, nominal bore and Light, Medium or Heavy class. Add the galvanizing standard and current coating requirement as a separate phrase. Then state length, threaded and coupled or plain ends, coupling quantity, marking, packing and inspection. The PO should not rely on a shorthand such as first quality GI because that phrase leaves the class and coating unmeasurable.

For tender supply, attach the relevant BOQ page and approved material schedule. Ask the supplier to reproduce the description on the quotation rather than returning a shortened trade description. Before PO release, confirm the mill, BIS licence details where required, MTC contents, coating record, TPI stage, consignee and e-way bill address.

• Write NB and class together because the same bore can carry different walls.
• Specify hot-dip galvanizing and the coating standard instead of accepting the word galvanized alone.
• State whether couplings are included and whether both ends need thread protection.
• List the test and inspection records required with each dispatch tranche.
• Separate material, freight, unloading and applicable taxes in the commercial comparison.

Worked weight example for GI pipe planning

The steel-tube weight gives a useful planning baseline before adding zinc, socket, threading and permitted variation. Using 60.3 mm OD and 3.6 mm wall, weight = (OD - t) x t x 0.02466 kg/m. The result is (60.3 - 3.6) x 3.6 x 0.02466 = 5.03 kg/m. A 6 m plain steel length is about 30.20 kg on this theoretical basis.

Do not use that result as the final GI dispatch weight. Galvanizing and the coupling add mass, while mill tolerance affects the steel weight. Use the theoretical figure to sense-check the BOQ, then settle billing and receipt against the agreed actual or theoretical basis. The bundle schedule should show NB, class, length count and total quantity.

GI pipe inspection and common procurement failures

Inspect the pipe identity before focusing on appearance. Confirm the marking, NB, class, length and heat or lot link to the documents. Examine the zinc surface for bare areas, heavy lumps, flaking, handling damage and blocked threads. Check sockets separately because an incomplete socket count creates an immediate site shortage even when the pipe quantity is correct.

In practice, mixed classes cause the most serious receiving errors. Light, Medium and Heavy pipes can share the same NB and look similar in a strapped bundle. Keep classes on separate bundle tags and verify wall at the agreed sampling frequency. A bright surface is not evidence of coating mass. Use the specified test record and inspection plan.

• Do not compare GI offers unless the NB, wall class, coating callout and end finish match.
• Do not accept damaged threads hidden under loose plastic caps.
• Do not mix sockets, caps and loose pipe counts on one unverified tally.
• Do not let outdoor bundles sit in contact with standing water or aggressive chemicals.
• Record coating or handling rejections before the vehicle leaves the loading point.

IS 1239 and IS 4736 work together

IS 1239 Part 1 governs the steel tube dimensions and class used in this catalogue. IS 4736 governs hot-dip zinc coating on the tube; the amended coating requirement used here is a minimum zinc coating mass of 360 g/m². Put both standards and their ordered editions on the purchase description so the steel wall and the protective layer can each be checked.

ASTM A53 also covers black and hot-dipped zinc-coated steel pipe, including welded and seamless forms. Do not mix an ASTM description with an IS class label without a written technical reconciliation. For a government or consultant-approved project, the sanctioned material schedule controls the standard, testing, marking and acceptance documents.

Dispatch GI pipe from Kanpur across UP and nearby states

GI buyers in Kanpur Dehat, Unnao, Panki, Dada Nagar, Jajmau, Chakeri and Fazalganj should require the quotation to identify size, class, proposed mill source, bundle quantity, current availability and delivery basis. No daily or multi-state dispatch claim on this page should be treated as a service commitment.

Lucknow, Agra, Prayagraj, Varanasi, Gorakhpur, Jhansi, Bareilly and Patna buyers should provide the destination PIN code and unloading constraints. Long bundles need suitable vehicle support and protected threaded ends. Ask for separate tranches when a PWD or JJM programme has multiple consignee sites, document sets or inspection releases.

• GI pipes in Kanpur Local ordering and documentation guidance.
• GI pipe price list Indicative ex-warehouse Kanpur bands from the matching price page.
• GI pipes in Lucknow Nearby city delivery and enquiry context.
• Kanpur steel market Local buying orientation for steel pipe procurement.
• Request a quotation Send the BOQ, coating requirement, documents and destination.

What to include in the RFQ

1. Specify the relevant standard or grade where known.
2. Provide OD or NB, wall thickness or schedule, required length, and quantity.
3. State the delivery city or PIN code and any unloading constraints.
4. List MTC, IBR, TPI, marking, inspection, or other documentation requirements.
5. Copy the approved standard, NB, Light or Medium or Heavy class and application from the BOQ.
6. State the ordered edition of IS 4736 with the amended 360 g/m² minimum zinc coating requirement.
7. Choose threaded and coupled, plain, grooved or other approved end preparation.
8. List MTC, coating test record, BIS marking, TPI, inspection release and consignee documents.
9. State length, pieces, sockets, packing, bundle tags and protection for threads and zinc surfaces.
10. Define ex-warehouse Kanpur or delivered basis, freight, unloading, transit risk and applicable taxes separately.

Key points for Kanpur buyers

• A complete GI specification names both the steel-tube standard and the zinc-coating standard.
• NB and class must stay together throughout the quotation, PO, bundle tag and receipt check.
• The amended IS 4736 coating requirement used here sets a 360 g/m² minimum zinc coating mass.
• The project design decides where GI pipe is suitable; coating alone does not decide service.
• Confirm price, stock, freight, documents and dispatch terms for each Kanpur RFQ.

Sources and standards references

• IS 1239 (Part 1):2004: Steel Tubes for Water and Sewage, Part 1 Bureau of Indian Standards
• IS 4736:1986 with amendments: Hot-dip zinc coatings on mild steel tubes Bureau of Indian Standards
• ASTM A53/A53M-24: Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless ASTM International

Frequently asked questions