SS Spectacle Blind Flange Supplier India | Figure-8 Blind Paddle Blind Spacer | ASTM A240 A182 SS316 SS304 | Class 150 300 600 | ASME B16.48 | DN15–DN600 | KELOR

Description

SS Spectacle Blind Flange (Figure-8 Blind) & Paddle Blind Supplier India | ASTM A240 A182 SS316 / SS304 | Class 150 / 300 / 600 | DN15–DN600 | ASME B16.48 / API 590 | Refinery / Chemical Plant Positive Isolation | KELOR

Supplier: Krishna Industries (KELOR) – Ahmedabad, Gujarat, India
Established: 2017 | GSTIN: 24AKLPP6499B1ZT | IEC: AKLPP6499B
MOQ: 10 Nos | Material: ASTM A240 SS316/SS304 / ASTM A182 F316/F304
Standard: ASME B16.48 / API 590 | Sizes: DN15–DN600 | Pressure: Class 150–600

SS Spectacle Blind Flange Supplier in India

Krishna Industries (KELOR), based in Ahmedabad, Gujarat, is a B2B supplier of SS Spectacle Blind Flanges (Figure-8 Blinds) and Paddle Blinds / Paddle Spacers — ASTM A240 Grade 316 / Grade 304 SS plate (standard, DN15–DN300) — ASTM A182 F316 / F304 forged (Class 600 and large bore) — spectacle blind (one-piece figure-8 — rotate to blind or open position) / paddle blind + paddle spacer (two-piece — slide in and out) — raised face (RF) — Class 150 / 300 / 600 — DN15 (½”) to DN600 (24″) — ASME B16.48 / API 590 — ASME B16.48 thickness per class and size — GST invoice — MOQ 10 Nos — Pan India dispatch from Ahmedabad.

Spectacle blinds and paddle blinds are positive isolation devices — physical metal barriers installed in the pipeline to provide mandatory isolation for maintenance, hot work, confined space entry, and shutdown operations. Unlike a closed valve, a spectacle blind or paddle blind cannot leak, cannot be opened inadvertently, and provides visible confirmation of isolation status through the protruding tab or handle. This makes them the standard positive isolation device in Indian refineries, petrochemical plants, and chemical plants per OISD-105 and international safety standards.

Spectacle Blind vs Paddle Blind vs Standard Blind Flange — Complete Comparison

Why Positive Isolation is Mandatory — Valve Closure Is Not Sufficient

The requirement for spectacle blinds and paddle blinds in Indian process plant maintenance is driven by formal safety standards — not by preference. Understanding the regulatory basis helps procurement teams specify the correct quantity and type for each isolation point on the plant.

Material and Grade Selection

Technical Specifications

Applications in Indian Industries

• Indian refineries — IOCL, BPCL, HPCL, Reliance — turnaround and shutdown isolation — SS316 paddle blind DN150–DN600 Class 150/300 — process vessel nozzle isolation before vessel entry for inspection or repair — pump and heat exchanger isolation before maintenance — crude distillation unit, vacuum distillation unit, hydrotreater shutdown isolation — formal blind register with each paddle blind tagged and signed-out per OISD-105 work permit — paddle blind for large bore DN300+ where figure-8 rotation is impractical
• Chemical plants — Ankleshwar, Vapi, Dahej GIDC — SS316 spectacle blind DN50–DN200 Class 150/300 — process line isolation for hot work (cutting, welding, grinding) on adjacent equipment — toxic chemical line isolation before maintenance on downstream equipment — figure-8 spectacle blind at DN15–DN200 for fast rotation without full bolt disassembly — critical in chemical plant where process line contains toxic or flammable chemicals
• Pharma API plants — GMP isolation — SS316L spectacle blind DN25–DN100 Class 150 — process line isolation during equipment cleaning validation and maintenance — GMP documentation requires confirmation of isolation status — spectacle blind tab position visually confirmed and recorded in batch record before maintenance team entry — F316L matches GMP piping system material specification
• Petrochemical plants — new construction and commissioning — SS316 paddle blind and spacer DN50–DN400 Class 150/300/600 — temporary isolation of piping sections during phased commissioning — all spectacle blinds and paddle blinds registered in commissioning blind register — positive sign-off required before each section is commissioned — prevents inadvertent pressurisation of sections still under construction
• EPC project supply — complete piping BOM — SS316 spectacle blinds and paddle blinds across all sizes and pressure classes — supplied as part of project piping material BOM alongside weld neck flanges, slip-on flanges, blind flanges, stud bolts, and gaskets — consolidated single order and single GST invoice — MTC for all material grades

Related Products — Krishna Industries (KELOR)

• SS Blind Flange — solid plate bolted to flange face — for permanent end closure, hydrostatic pressure testing, nozzle blanking — not for repeated process isolation switching — the standard end closure product distinct from spectacle blinds
• SS Weld Neck Flange — Class 150–1500 inline connection flanges — paired with spectacle blinds at process isolation points on the same SS piping system
• SS Slip-On Flange — Class 150/300 utility SS piping flanges — spectacle blinds installed at isolation points in the same utility piping systems
• Stud Bolts — ASTM A193 B8M (SS316) — SS316 studs for SS flanged joints — used at the flanged joints where spectacle blinds are installed — B8M studs prevent galvanic corrosion at SS isolation points
• Gate Valve — upstream and downstream isolation valves at spectacle blind locations — valve closed plus spectacle blind inserted provides the standard double isolation arrangement for Indian process plant maintenance permits

Frequently Asked Questions

1. What is the difference between a spectacle blind and a paddle blind and when should I specify each?

A spectacle blind (figure-8 blind) is one piece — solid blind half connected to open ring half — permanently installed between two flanges and rotated to switch between isolated and open states without removing flange bolts. A paddle blind is a separate solid plate with handle that is slid into the flange joint (and a separate paddle spacer ring slid in when the line is open). Specify spectacle blind for DN15–DN200 where the figure-8 can be rotated within the pipe spread available when flange bolts are loosened — the single-piece design prevents component loss and is faster to operate. Specify paddle blind + paddle spacer for DN250+ where the weight and size of a figure-8 makes rotation impractical — individual paddle blind and spacer are lighter to handle at large bore. Both provide equivalent positive isolation.

2. Why is a closed gate valve or ball valve not accepted as positive isolation for a hot work permit in an Indian refinery?

OISD-105 (Oil Industry Safety Directorate Standard 105 — Work Permit System) requires positive isolation before issuing hot work or confined space entry permits on process lines in Indian oil and gas installations. A closed valve does not qualify as positive isolation because valves can leak through worn seats (especially in hydrocarbon service where valve seats erode), can be inadvertently opened by a second operator who is unaware of the ongoing maintenance work, and can fail due to actuator malfunction on automated valves. A spectacle blind or paddle blind inserted in the blind position provides a solid metal plate between the live process and the work area — physically impossible to bypass without removing the flange joint. The visible protruding tab or handle confirms isolation status to the permit supervisor and the working team. This is why every Indian refinery and petrochemical plant maintains a formal blind register tracking the location and status of every spectacle blind and paddle blind on the plant.

3. What gasket should be used with spectacle blinds in SS piping?

When the spectacle blind is in the ring (open) position, the ring half sits between the two flanges and gaskets are required on both faces of the ring — two gaskets per spectacle blind joint. When the blind half rotates into position, the solid face contacts the gasket on the upstream side only (no gasket required on downstream face of solid blind). For Class 150 SS piping: compressed fibre (CAF) or PTFE gaskets — cut to suit the raised face dimensions. For Class 300 and above: spiral wound SS316/graphite gasket — the standard Indian refinery and chemical plant gasket for medium to high pressure SS flanged joints. Gaskets must be replaced each time the spectacle blind is rotated — the gaskets deform to the flange face on first compression and do not provide reliable sealing if reused. A set of replacement gaskets should be stocked with each spectacle blind location in the plant maintenance stores.

4. How thick must a spectacle blind be for a given pressure class?

ASME B16.48 specifies the minimum thickness for the blind half of line blanks per pressure class, nominal pipe size, and material group. The blind half must withstand the full line pressure acting across its unsupported circular area — thickness increases rapidly with pipe size and pressure class. As a reference, a DN150 Class 150 SS316 spectacle blind blind-half is approximately 8–10mm thick; a DN150 Class 300 blind-half is approximately 14–16mm. Do not accept spectacle blinds thinner than ASME B16.48 minimum — under-thickness blinds can fail in service under line pressure. Krishna Industries supplies spectacle blinds to ASME B16.48 minimum thickness with MTC confirming material grade.

5. What is the MOQ?

MOQ is 10 Nos per line item. EPC and refinery project supply — full piping isolation BOM across all sizes and pressure classes — spectacle blinds and paddle blind/spacer pairs — with MTC, dimensional report, and GST invoice. WhatsApp type (spectacle blind / paddle blind + spacer), material grade, pressure class, size list, and quantity for project pricing within 2 hours.

Conclusion

Krishna Industries (KELOR) supplies SS Spectacle Blind Flanges (Figure-8 Blinds) and Paddle Blinds / Paddle Spacers for process isolation in Indian refineries, petrochemical plants, chemical plants, and pharma plants — ASTM A240 SS316 / SS304 plate (standard) — ASTM A182 F316 / F304 forged (Class 600+) — spectacle blind (one-piece figure-8, DN15–DN200) / paddle blind + paddle spacer (two-piece, DN15–DN600) — raised face (RF) — Class 150 / 300 / 600 — DN15 (½”) to DN600 (24″) — ASME B16.48 / API 590 — ASME B16.48 thickness per class and size — MTC supplied — GST invoice — Pan India dispatch from Ahmedabad. WhatsApp type, material, pressure class, size list, and quantity for project pricing within 2 hours.