Blind Flange

Blind Flange

Brand: LOCUS
Material: Carbon Steel, Stainless Steel, Mild Steel, Alloy Steel, or Custom
Standards: ANSI, ASME B16.5, DIN, EN, JIS, BS, IS
Sizes: ½” to 48” (DN15 to DN1200) or as per customer requirement
Pressure Rating: PN6, PN10, PN16, PN25, PN40, PN64, Class 150 to 2500
Connection Type: Bolted – No bore (fully closed)

Description

1. Product Description

LOCUS Blind Flanges are solid, flat plates used to close off the ends of piping systems, valves, or equipment nozzles. These flanges are ideal for systems requiring future extension or where pressure testing, maintenance, or isolation is needed. Manufactured to global standards (ANSI/ASME/DIN), they offer strength, leak-proof sealing, and corrosion resistance.

2. Product Specifications

Parameter	Details
Material	SS304, SS316, MS, Carbon Steel, Duplex, etc.
Size Range	½” to 48” (DN15 to DN1200)
Thickness	As per ASME B16.5, custom on request
Pressure Rating	Class 150 – 2500 / PN6 – PN64
Finish	Black Oxide / Machined / Polished / Painted
Face Type	Flat Face (FF), Raised Face (RF), RTJ
Coating (optional)	PTFE, Epoxy, Zinc-plated, etc.
Standard Compliance	ASME B16.5, DIN 2527, EN 1092, IS Standards

3. Working Principle

A blind flange is used to block off or terminate a piping line. It can be bolted or unbolted when isolation or access to the system is required. It is designed to handle high-pressure and high-temperature fluids without leakage when paired with proper gaskets and bolts.

4. Principle

Sealing Mechanism: When the blind flange is bolted with a gasket to a mating flange or stub end, it forms a static seal that blocks the flow.
Load Bearing: Blind flanges must withstand system pressure and mechanical loads during operation.

5. Assembly Process

Select appropriate flange size, material, and pressure rating.
Place gasket between blind flange and mating flange face.
Align bolt holes of flanges and insert bolts.
Tighten bolts in a star pattern to ensure uniform sealing pressure.
Perform pressure test if required.

6. Installation Process

Clean mating surfaces (pipe ends/flange faces).
Position the blind flange in place.
Use standard torque guidelines to tighten bolts with torque wrench.
Apply sealant if needed for additional sealing.
Inspect after installation for leaks.
Record and tag for maintenance schedule.

7. Technical Specifications

Attribute	Value
Design Standard	ASME B16.5 / B16.47 / DIN / IS / EN
Operating Temperature	-20°C to 600°C (depending on material)
Operating Pressure	Up to 2500 psi
Tolerance	As per applicable standards
Gasket Type Compatibility	Spiral Wound / Ring Type / Rubber / PTFE
Surface Finish	3.2 – 6.3 Ra (machined face)
Corrosion Resistance	High (depending on material selection)

8. Troubleshooting Guide

Issue	Possible Cause	Solution
Leakage at joint	Improper gasket placement or low bolt torque	Re-torque bolts in star pattern; replace gasket
Bolt misalignment	Incorrect flange orientation or pipe stress	Align flange holes properly, support pipe load
Corrosion on flange face	Poor material selection or environment	Use corrosion-resistant coating or upgrade material
Flange cracking	Over-tightening or material fatigue	Follow torque specs and inspect material before use

9. HS Codes

Product	HS Code (India)	Description
Blind Flange	73072100	Flanges, of stainless steel, for tubes or pipes

✅ You can also use 73072200 (for alloy steel), 73072300 (for iron/steel), depending on material.

10. Frequently Asked Questions (FAQ)

Q1: What’s the purpose of a blind flange?
👉 It is used to close off or terminate the end of a piping system, especially where future extension or maintenance is expected.

Q2: Can I reuse a blind flange after removal?
👉 Yes, if it is not damaged, warped, or corroded. Always inspect before reuse.

Q3: What gasket should be used?
👉 Depends on pressure and fluid. Spiral wound or rubber gaskets are common.

Q4: How is blind flange different from a slip-on flange?
👉 Blind flange has no bore and is used to block flow, while a slip-on flange is used to connect pipes.

Q5: Do blind flanges hold pressure?
👉 Yes, they are designed to handle the full system pressure when properly installed.

11. Applications

LOCUS Blind Flanges are widely used in:

- 🔧 Petrochemical & Oil Refineries
- 🏭 Chemical & Process Plants
- 💧 Water & Wastewater Pipelines
- 🔥 Power Plants (Thermal/Nuclear)
- 🧪 Laboratory & Pilot Plants
- 🛢️ Storage Tanks & Pressure Vessels
- 🚢 Shipbuilding & Marine Applications
- 🚘 Automobile Exhaust & Hydraulic Lines