76mm Pipe Insulation Guide: Sizes, Materials & Wall Thickness

76mm Pipe Insulation — Complete UK Guide

76mm pipe insulation is specified for 76.1mm OD pipework — a large bore commercial and industrial pipe size used in district heating mains, large commercial heating systems, industrial process pipework and plant room headers. This guide covers material selection, wall thickness, BS 5422 compliance and installation for 76mm pipework.

Shop 76mm pipe insulation: Browse the full 76mm collection

76mm Pipe — OD, Nominal Bore and Insulation Sizing

76mm pipe insulation fits pipework with an outside diameter (OD) of approximately 76mm. This covers:

• 76.1mm OD copper pipe — large bore copper, used in commercial heating and hot water systems
• 3 inch nominal bore (NB) steel pipe — actual OD approximately 88.9mm — requires 89mm bore insulation, not 76mm
• 2½ inch NB steel pipe — actual OD approximately 73mm — check manufacturer data for correct bore

Always measure the actual OD of the pipe before ordering. Read our guide: Copper Pipe Size vs Insulation Size

What is 76mm Pipework Used For?

76mm pipework is a large bore commercial and industrial pipe size used in:

• District heating and heat network primary distribution mains
• Large commercial heating mains — LTHW primary circuits in large commercial buildings, hospitals and schools
• Industrial process pipework and steam distribution
• Large plant room headers and boiler connections
• Large hot water primary circuits in hotels, hospitals and large residential developments

76mm Pipe Insulation Materials

Armaflex EVO — Elastomeric Foam

Armaflex EVO is available for 76mm HVAC and chilled water pipework.

• Thermal conductivity: λ ≤ 0.033 W/mK at 0°C
• Operating temperature: -50°C to +105°C
• Fire rating: Class O (BS 476), B-s2,d0 (EN 13501)
• Available in 19mm, 25mm and 32mm wall thickness for 76mm bore

Best for: Chilled water, condensation control, HVAC

Kingspan Kooltherm — Phenolic Foam

Kingspan Kooltherm is the preferred specification for 76mm commercial heating and district heating pipework requiring BS 5422 compliance.

• Thermal conductivity: λ = 0.025 W/mK (aged value)
• Operating temperature: -180°C to +110°C
• Fire rating: Class O (BS 476), B-s1,d0 (EN 13501)
• Available in 30mm, 40mm and 50mm wall thickness for 76mm bore
• 60kg/m³ and 120kg/m³ grades available for district heating applications

Best for: District heating, large commercial heating mains, BS 5422 compliance

Rockwool Rocklap — Mineral Wool

Rockwool Rocklap is the standard specification for high-temperature and fire-rated applications on 76mm pipework.

• Fire rating: A1 non-combustible (Euroclass A1)
• Operating temperature: up to 750°C continuous
• Available in 30mm, 40mm and 50mm wall thickness for 76mm bore

Best for: Steam pipework, high-temperature heating mains, industrial process pipework, fire-rated applications

Wall Thickness Selection for 76mm Pipe Insulation

BS 5422 Requirements for 76mm Pipe Insulation

Under BS 5422, the minimum insulation thickness for 76mm OD pipework (76.1mm OD band) on a standard LTHW heating system is:

• Kingspan Kooltherm (λ = 0.025) — 30mm wall
• Rockwool Rocklap (λ = 0.034) — 40mm wall

For district heating and higher temperature applications, 40mm or 50mm wall is typically specified regardless of material. Read our full guide: BS 5422 Pipe Insulation Standards Guide

Shop 76mm Pipe Insulation by Wall Thickness

• 25mm wall — chilled water and condensation control
• 30mm wall — BS 5422 commercial heating (Kooltherm)
• 40mm wall — district heating and high temperature
• 50mm wall — steam, industrial and maximum thermal performance

Related Pipe Size Guides

• 54mm Pipe Insulation Guide
• 42mm Pipe Insulation Guide
• 35mm Pipe Insulation Guide
• Pipe Insulation by Pipe Size — Complete Sizing Guide
• Pipe Insulation Wall Thickness Guide
• BS 5422 Pipe Insulation Standards Guide
• Why Kingspan Kooltherm Is Transforming HVAC Pipe Insulation

Frequently Asked Questions

What size insulation do I need for 76mm pipe?

You need pipe insulation with a 76mm bore. Always measure the actual OD of the pipe first — 76mm copper has an OD of 76.1mm. Steel pipe nominal bore sizes do not correspond directly to OD, so check the actual pipe OD before ordering.

What wall thickness do I need for 76mm pipe insulation?

For commercial heating BS 5422 compliance, 30mm Kooltherm is typically the minimum. For district heating, 40mm or 50mm is standard. For high-temperature and steam applications, 40mm or 50mm mineral wool is specified.

What is 76mm pipe insulation used for?

76mm pipe insulation is used on district heating mains, large commercial heating systems, industrial process pipework and large plant room headers. It is a large bore commercial and industrial pipe size with high order values — typically specified by M&E engineers and district heating contractors.

Is Kooltherm suitable for district heating pipework?

Yes. Kingspan Kooltherm 60kg/m³ and 120kg/m³ grades are specifically approved for district heating and heat network pipework. The higher density grades provide the compressive strength needed to resist point loads from pipe supports and clamps on district heating installations.