Issuing body
ASTM
Latest edition
C591-23
Region
USA, Global
Equipment items
1
Scope
Rigid PIR/PUR insulation for pipes and equipment, typically −180 °C to +120 °C.
Key requirements (7)
- Polyisocyanurate (PIR) rigid cellular foam insulation.
- Service temperature: –183 °C to +149 °C.
- Thermal conductivity: ~0.022 W/m·K at 24 °C (initial); ~0.026 aged.
- Closed-cell, low water absorption.
- Density: 32–50 kg/m³ typical; 40–96 kg/m³ for higher compressive grades.
- Used widely for refrigerated piping, LPG/ammonia storage tank base insulation.
- Combustible — needs fire protection in high-risk areas.
Related standards (1)
Applied to 1 equipment item
Insulation & Refractory