Flanges

About Flanges

Carbon steel, stainless steel, and alloy steel flanges, weld neck, slip-on, blind, socket weld, threaded and lap joint, conforming to ASME B16.5 and ASME B16.47 for process piping, pressure vessels, and industrial equipment.

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.

• Oil & Gas: Pipeline flanged connections, wellhead equipment, manifolds.
• Power Generation: Boiler connections, turbine piping, feedwater systems.
• Chemical & Pharma: Reactor vessels, process piping, clean-room systems.
• Water & Infrastructure: Pump connections, valve assemblies, water treatment plants.

Potential source references

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

• Regal Sales Corporation
• Kanak Metal
• Tube Trading Co.
• Dynamic Forge & Fittings

Applicable standards and specifications

• ASME B16.5

Technical Definition, Geometries, and Governing Standards

Flanges create removable bolted joints between pipes, valves, pumps, vessels, and other equipment. The purchase description must coordinate the flange type, material, nominal size, pressure class, facing, mating pipe wall, bore, end preparation, and applicable dimensional standard. Treating a flange as only a size-and-class item leaves the fabricator to resolve important details after delivery.

This product record uses the six pressure classes listed in the specification table: 150#, 300#, 600#, 900#, 1500#, and 2500#. The applicable dimensional standard and series still depend on nominal size and the project specification. Pressure-temperature suitability must be checked against the material group and the specific table required by the design code; class alone is not a universal working-pressure value.

Service Application and Material Compatibility Matrix

Material selection follows the line class and service assessment. Carbon steel, stainless steel, low-temperature steel, and alloy steel forgings have different chemistry, heat treatment, toughness, corrosion, and temperature considerations. Copy the full grade and any supplementary requirement from the project specification. A generic material family such as 'SS' or 'alloy' is not enough for a controlled purchase.

Check the facing of both mating components, the gasket type, bolt material, and equipment limitations as one assembly. Do not replace a specified forged flange with a fabricated ring or plate blank without written engineering approval. If an equipment nozzle or pump casing has a different facing, ask the designer to confirm the joint arrangement before procurement.

ASME B16.5 Raised Face (RF) Dimension and Bolt Hole Table

Repository dimensional rows for preliminary flange identification. Confirm the applicable standard edition and certified dimensions for the offered type and material.

Use these repository dimensions for preliminary identification only. Confirm the applicable standard edition, material group, flange type, facing, bore, and certified dimensions for the item offered.

Worked Bolt-Circle Sizing and Geometry Calculation

To assist site fabrication teams in Kanpur's industrial zones (such as Fazalganj or Dada Nagar), let us calculate the geometric spacing for a 4" NPS Class 150 Weld Neck Raised Face (WNRF) flange. A piping supervisor needs to verify the hole-spacing before drilling matching backing plates.

First, the supervisor identifies the bolt-circle diameter (D_bc) from ASME B16.5 Table 8:

D_bc = 190.5 mm.

The total circumference of the bolt-circle is computed using the standard circle formula:

Circumference (C) = pi * D_bc

Calculation: C = 3.14159 * 190.5 mm = 598.47 mm.

Since Class 150 4" NPS flanges require exactly 8 bolt holes, the linear arc spacing between adjacent hole centers is calculated:

Arc Spacing = Circumference / Number of Holes = 598.47 mm / 8 = 74.81 mm.

The calculated arc distance is a layout cross-check, not a drilling template. Fabricators should verify the certified flange dimensions, hole count, hole diameter, orientation, and mating component before machining a backing plate.

Common Procurement Mistakes and Failure Modes

Flange orders can become incomplete when the bore, facing, material, or mating details are missing:

• Weld-neck bore omitted: Give the mating pipe outside diameter and wall or schedule. Ask the supplier to state the offered bore so the fabricator can check internal alignment before welding.
• Manufacturing route unclear: State whether the project calls for a forging and identify the material specification. A visual similarity between a machined ring and a forged item does not establish material compliance.
• Facing description incomplete: Name the face type and required finish from the project specification. Coordinate it with the gasket and mating flange, and protect finished faces during storage and transport.

Kanpur Steel Market Pricing Mechanics & Regional Delivery Basis

Flanges are normally compared per piece, but a useful quotation also states the manufacturer, material, type, facing, class, size, bore, finish, certificate scope, and delivery basis. Ask suppliers to separate special machining, testing, inspection, packing, and freight so unlike offers are not compared as if they were identical.

For Jajmau, Panki, Dada Nagar, Fazalganj, other Kanpur-area sites, or an outstation destination, send the delivery PIN code and unloading constraints. Require the offer to state current availability, proposed loading date, transport responsibility and the basis of any transit estimate; this page makes no corridor promise.

Agree the dispatch documents before release. The pack may include the invoice, e-way bill, packing list, mill test certificate, heat list, dimensional report, and third-party release note where ordered. Match piece markings to the certificate and packing list before the items are mixed with project stock.

Standards and Testing Compliance

Pressure-temperature selection must use the specific primary rating table required by the governing design code, material group, standard edition, and project conditions. This page does not assign a universal maximum allowable working pressure to Class 150 at a selected temperature. Put the design pressure, design temperature, material grade, class, and applicable table reference in the RFQ so the engineering check is explicit.

Key Takeaways for Kanpur Flange Sourcing

Procurement and quality check guidelines for local industrial buyers in Uttar Pradesh:

• Manufacturing route: State the required forging specification and ask the quotation to confirm the offered route and manufacturer.
• Facing control: Identify RF, RTJ, or FF and the required finish; protect the face from impact and corrosion until installation.
• Document control: List the MTC, dimensional report, marking, inspection release, and any Form III-C requirement in the enquiry.
• Delivery control: Give the destination, packing method, unloading plan, and required-on-site date so dispatch can be confirmed against actual availability.

Flange inspection and fabrication handoff

Build the receiving checklist around the joint, not only the loose flange. Record the line number, mating equipment or pipe, flange type, nominal size, class, material, facing, bore, pipe wall, gasket, and bolting specification. This lets stores direct the item to the correct fabrication package instead of placing visually similar flanges in one bin.

At receipt, compare markings with the packing list and certificate. Check accessible dimensions, bolt-hole count and orientation, bore, hub, end preparation, facing condition, and protective covering. Photograph damage or an unreadable heat mark before acceptance. Keep machined faces off the floor and use separators that do not score the serrations.

Before fit-up, the fabricator should confirm internal alignment, root preparation, flange orientation, bolt access, and gasket-face protection. Any mismatch should return to engineering and purchasing as a documented query. Site machining, bore changes, weld build-up, or facing repair should not proceed from a verbal instruction.

For a mixed flange package, use the line list to sort items by piping class and area before issuing them to fabrication. Similar outside diameters can hide different classes, bores, facings, or materials. Apply temporary identification that survives blasting and painting, and define who restores permanent marking after any approved machining or repair.

Bolting and gaskets should be checked as controlled companion items. Confirm stud length, nut type, material, coating, gasket construction, storage, and traceability from the approved bill of materials. Keep facing protectors fitted until the joint is ready. A clean, undamaged face and the correct assembly procedure matter as much as the flange certificate.

Before shipment from Kanpur, agree packing that prevents carbon-steel contact with stainless surfaces where the project restricts contamination. Separate loose spectacle blinds, orifice items, rings, and small socket-weld or threaded flanges in labelled crates. The receiving list should show package location so the site does not open every crate to find one tagged item.

After welding, preserve the relationship between the flange, weld record, welder identity, examination report, and line number in the turnover dossier. Where the project requires dimensional or alignment checks after welding, record them before painting or insulation hides the joint. This handoff gives commissioning a traceable answer when a joint cannot be assembled or tested.

• Send a flange RFQ Provide type, size, class, material, facing, bore or pipe wall, quantity, documents, and delivery details.
• Prepare for a Kanpur inspection Review local buying information before arranging collection or an inspection.
• Coordinate matching valves Check valve end connections and facing details in the same procurement package.

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.

Frequently asked questions