AP/ArmaFlex® W
AP/ArmaFlex W is an off-white, fiber-free, closed-cell elastomeric thermal insulation supplied in tubular pipe form, with nominal wall thicknesses from 1/2″ to 1-1/2″ and tubular inside diameters from 1/2″ up to 6 IPS. It carries a declared thermal conductivity as low as 0.034 W/(m·K) at 50°F mean temperature and is rated for service from -297°F to 220°F (3/8″ through 1″ walls) or up to 300°F (1-1/2″ EPDM-based wall). It is available with or without a factory-applied self-seal (lap seal) closure system for labor-saving field installation.
Key Properties
- Thermal Conductivity: λd ≤ 0.034 W/(m·K) [k ≤ 0.235 Btu·in/(h·ft²·°F)] at 50°F Mean Temperature, 3/8″ through 1″ walls (NBR/PVC-based); λd ≤ 0.040 W/(m·K) [k ≤ 0.278 Btu·in/(h·ft²·°F)] at 50°F Mean Temperature, 1-1/2″ wall (EPDM-based) — ASTM C518, ASTM C177
- Water Vapor Permeability: 0.05 perm-inch (0.725 x 10⁻¹³ kg/(s·m·Pa)) for NBR/PVC products; 0.08 perm-inch (1.16 x 10⁻¹³ kg/(s·m·Pa)) for EPDM products — ASTM E96 Desiccant Method
- Service Temperature Range: -183°C to 105°C (-297°F to 220°F) for 3/8″ through 1″ walls (NBR/PVC-based); -183°C to 150°C (-297°F to 300°F) for 1-1/2″ wall (EPDM-based) — ASTM C534
- Fire Performance: Flame Spread Index less than 25; Smoke Developed Index less than 50; 25/50 rated — ASTM E84 and UL 723
- Density: 3 to 6 lb/ft³ (48 to 96 kg/m³) — ASTM D1667
- Water Absorption: 0.2% by volume — ASTM C1763, ASTM C2093
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Physical Properties
| Property | Value | Test Method |
| Density | 3 to 6 lb/ft³ (48 to 96 kg/m³) | ASTM D1667 |
Thermal Properties
| Property | Value | Test Method |
| Service Temperature, 3/8″ through 1″ Walls (NBR/PVC-based) | -183°C to 105°C Min./Max. (-297°F to 220°F) | ASTM C534 |
| Service Temperature, 1-1/2″ Wall (EPDM-based) | -183°C to 150°C Min./Max. (-297°F to 300°F) | ASTM C534 |
| Thermal Conductivity (λd), 50°F Mean Temp. (10°C), 3/8″–1″ Walls (NBR/PVC) | ≤ 0.034 W/(m·K) [≤ 0.235 Btu·in/(h·ft²·°F)] | ASTM C518, ASTM C177 |
| Thermal Conductivity (λd), 75°F Mean Temp. (24°C), 3/8″–1″ Walls (NBR/PVC) | ≤ 0.0353 W/(m·K) [≤ 0.245 Btu·in/(h·ft²·°F)] | ASTM C518, ASTM C177 |
| Thermal Conductivity (λd), 100°F Mean Temp. (38°C), 3/8″–1″ Walls (NBR/PVC) | ≤ 0.037 W/(m·K) [≤ 0.257 Btu·in/(h·ft²·°F)] | ASTM C518, ASTM C177 |
| Thermal Conductivity (λd), 125°F Mean Temp. (52°C), 3/8″–1″ Walls (NBR/PVC) | ≤ 0.039 W/(m·K) [≤ 0.268 Btu·in/(h·ft²·°F)] | ASTM C518, ASTM C177 |
| Thermal Conductivity (λd), 50°F Mean Temp. (10°C), 1-1/2″ Wall (EPDM) | ≤ 0.040 W/(m·K) [≤ 0.278 Btu·in/(h·ft²·°F)] | ASTM C177, ASTM C518 |
| Thermal Conductivity (λd), 75°F Mean Temp. (24°C), 1-1/2″ Wall (EPDM) | ≤ 0.040 W/(m·K) [≤ 0.28 Btu·in/(h·ft²·°F)] | ASTM C177, ASTM C518 |
| Thermal Conductivity (λd), 100°F Mean Temp. (38°C), 1-1/2″ Wall (EPDM) | ≤ 0.041 W/(m·K) [≤ 0.289 Btu·in/(h·ft²·°F)] | ASTM C177, ASTM C518 |
| Thermal Conductivity (λd), 125°F Mean Temp. (52°C), 1-1/2″ Wall (EPDM) | ≤ 0.043 W/(m·K) [≤ 0.300 Btu·in/(h·ft²·°F)] | ASTM C177, ASTM C518 |
Note: At -40°F (-40°C) the insulation becomes brittle; this hardening characteristic does not affect thermal efficiency or water vapor permeability. For applications of -40°F to -297°F (-40°C to -183°C), contact Armacell.
Flame & Fire Performance
| Property | Value | Test Method |
| Surface Burning Characteristics | Flame Spread Index less than 25; Smoke Developed Index less than 50 (25/50 rated) | ASTM E84 and UL 723 |
Environmental Performance
| Property | Value | Test Method |
| Water Vapor Permeability (NBR/PVC products) | 0.05 perm-inch (0.725 x 10⁻¹³ kg/(s·m·Pa)) | ASTM E96 Desiccant Method |
| Water Vapor Permeability (EPDM products) | 0.08 perm-inch (1.16 x 10⁻¹³ kg/(s·m·Pa)) | ASTM E96 Desiccant Method |
| Water Absorption | 0.2% by volume | ASTM C1763, ASTM C2093 |
Product Dimensions
| Property | Value | Test Method |
| Wall Thickness, Standard Tube (nominal) | 1/2″, 3/4″, 1″, 1-1/2″ (13, 19, 25, 38 mm) | — |
| Tubular Inside Diameter, Standard Tube | 1/2″ up to 6 IPS (13 mm to 168 mm) | — |
| Length of Sections, Tubular | 6 ft (1.8 m); some larger sizes shipped in two 3 ft sections | — |
| Wall Thickness, Self-Seal Closure System (nominal) | 1/2″, 1″, 1-1/2″ (13, 25, 38 mm) | — |
| Tubular Inside Diameter, Self-Seal Closure System | 1/2″ to 2-5/8″ (13 mm to 67 mm) | — |
Compliance
- FM Approvals — Compliant (3rd party certified through 1-1/2″ wall thickness for pipe insulation up to 4 IPS; 1″ thickness for sheet and roll insulation)
- ISO 9001 — Compliant (Armacell North America’s quality management systems certified by Intertek)
- ASTM E84 — Compliant
- UL 723 — Compliant
- GREENGUARD Gold Certified — Compliant
- ASTM G21/C1338 — Compliant
- ASTM C534, Type I – Tube Grade 1 — Compliant
- ASTM D1056, 2C1 — Compliant
- ASHRAE 90.1 — Compliant (energy standards)
- NFPA 90A, 90B — Compliant
- International Mechanical Code (IMC) — Compliant
- International Energy Conservation Code (IECC) — Compliant
- International Residential Code (IRC) — Compliant
- Title 24: California Building Energy Efficiency Standards — Compliant
- EPA Registered MICROBAN® Antimicrobial Product Protection — Compliant
- HVAC system piping insulation
- VRV and VRF system piping insulation
- Chiller piping insulation
- Hot and cold water piping insulation
- Refrigeration piping and equipment insulation
Common industries: HVAC and mechanical contracting, commercial and industrial refrigeration, plumbing and mechanical piping, building construction.
AP/ArmaFlex W is a fiber-free, formaldehyde-free, off-white closed-cell elastomeric pipe insulation designed for condensation control and energy loss prevention on below-ambient and hot piping and equipment, including HVAC, VRV/VRF, chiller, hot and cold water, and refrigeration systems. Its closed-cell structure provides a built-in resistance to water vapor transmission, reducing reliance on separate vapor retarders, and the product is offered in tubular sections with or without a factory-applied self-seal (lap seal) closure system to reduce field labor.
The material is manufactured without CFCs, HFCs, HCFCs, PBDEs, or formaldehyde, is GREENGUARD Gold Certified for low VOC emissions, and incorporates EPA-registered MICROBAN® antimicrobial product protection. It has demonstrated resistance to fungal and mildew growth per ASTM G21/C1338, and Armacell’s North American quality management systems are certified to ISO 9001 by Intertek. Compliant with ASTM C534, ASTM D1056, ASTM E84, UL 723, ASHRAE 90.1, NFPA 90A, NFPA 90B, and applicable building energy codes (IMC, IECC, IRC, Title 24).
What differentiates AP/ArmaFlex W from fiberglass or other fibrous pipe insulation materials?
AP/ArmaFlex W is a fiber-free, formaldehyde-free, closed-cell elastomeric insulation whose cell structure provides built-in resistance to water vapor transmission, helping control condensation without a separate vapor retarder. It is low-VOC, GREENGUARD Gold Certified, includes EPA-registered MICROBAN® antimicrobial protection, and is available in an off-white finish with or without a factory-applied self-seal (lap seal) closure system for faster field installation.
Why does thermal conductivity matter in material selection for AP/ArmaFlex W?
Thermal conductivity determines how effectively the insulation limits heat gain or loss across piping and equipment. AP/ArmaFlex W has a declared thermal conductivity (λd) as low as 0.034 W/(m·K) at 50°F mean temperature for 3/8" through 1" walls, rising modestly at higher mean temperatures and for the heavier 1-1/2" EPDM-based wall, allowing insulation thickness to be selected to meet specific energy-efficiency and condensation-control requirements.
What is the service temperature range for AP/ArmaFlex W?
-183°C to 105°C (-297°F to 220°F) for 3/8" through 1" walls (NBR/PVC-based), and -183°C to 150°C (-297°F to 300°F) for the 1-1/2" wall (EPDM-based), per ASTM C534. At -40°F (-40°C) the material becomes brittle, though this does not affect thermal efficiency or water vapor permeability; for applications between -40°F and -297°F, contact Armacell.
Is AP/ArmaFlex W suitable for regulated or flame-rated environments?
Yes. AP/ArmaFlex W carries FM Approvals, is rated 25/50 (Flame Spread Index less than 25, Smoke Developed Index less than 50) per ASTM E84 and UL 723, is GREENGUARD Gold Certified, and conforms to ASHRAE 90.1 energy standards, NFPA 90A/90B, and building energy codes including the IMC, IECC, IRC, and Title 24 California Building Energy Efficiency Standards.
How should AP/ArmaFlex W be specified?
Specify grade (AP/ArmaFlex W), wall thickness, tubular inside diameter, with or without self-seal (lap seal) closure system, compliance requirements, dimensional tolerances, and finished format.
