AP/ArmaFlex + AP/ArmaFlex FS
AP/ArmaFlex and AP/ArmaFlex FS are closed-cell flexible elastomeric insulation materials with a declared thermal conductivity (λd) as low as 0.034 W/(m·K) [k ≤ 0.235 Btu·in/(h·ft²·°F)] at 50°F (10°C) and a density of 3 to 6 lb/ft³ (48 to 96 kg/m³). Both grades are rated for continuous service from -297°F (-183°C) up to 220°F (105°C) for NBR/PVC-based constructions, while 1-1/2″ and 2″ wall EPDM-based constructions are rated up to 300°F (149°C), and both achieve a surface burning rating of Flame Spread Index less than 25 and Smoke Developed Index less than 50 per ASTM E84/UL 723. AP/ArmaFlex is manufactured from nitrile rubber/polyvinyl chloride (NBR/PVC) for wall thicknesses up to and including 1″, while AP/ArmaFlex FS and insulation thicknesses greater than 1″ are manufactured from PVC-free Ethylene Propylene Diene Monomer (EPDM).
Key Properties
- Thermal Conductivity (λd), Declared: AP/ArmaFlex (NBR/PVC, 3/8″–2″ walls): ≤0.034–0.039 W/(m·K) [k ≤0.235–0.268 Btu·in/(h·ft²·°F)] across 50°F–125°F (10°C–52°C) / AP/ArmaFlex FS (EPDM, 1-1/2″ & 2″ walls): ≤0.040–0.043 W/(m·K) [k ≤0.278–0.300 Btu·in/(h·ft²·°F)] across the same temperature range
- Water Vapor Permeability: AP/ArmaFlex (NBR/PVC): 0.05 perm-inch (0.725 × 10⁻¹³ kg/(s·m·Pa)) / AP/ArmaFlex FS (EPDM): 0.08 perm-inch (1.16 × 10⁻¹³ kg/(s·m·Pa))
- Service Temperature Range: AP/ArmaFlex (NBR/PVC, all walls): -297°F to 220°F (-183°C to 105°C) / AP/ArmaFlex FS (EPDM, 1-1/2″ & 2″ walls): -297°F to 300°F (-183°C to 149°C)
- Fire Performance: Flame Spread Index less than 25, Smoke Developed Index less than 50 (AP/ArmaFlex tube insulation all thicknesses; AP/ArmaFlex FS sheet/roll through 2″; AP/ArmaFlex sheet/roll through 1″ — 1-1/2″ and 2″ sheet/roll NOT 25/50 rated) per ASTM E84, UL 723
- Density: 3 to 6 lb/ft³ (48 to 96 kg/m³)
- Water Absorption: 0.2% by volume
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Physical Properties
| Property | Value | Test Method |
| Density | 3 to 6 lb/ft³ (48 to 96 kg/m³) | ASTM D1667 |
| Water Absorption | 0.2% by volume | ASTM C209, ASTM C1763 |
Thermal Properties
| Property | Value | Test Method |
| Service Temperature Range, 3/8″ through 1″ Walls (NBR/PVC) | -183°C to 105°C (-297°F to 220°F) | ASTM C534 |
| Service Temperature Range, 1-1/2″ and 2″ Walls (NBR/PVC) | -183°C to 105°C (-297°F to 220°F) | ASTM C534 |
| Service Temperature Range, 1-1/2″ and 2″ Walls (EPDM) | -183°C to 149°C (-297°F to 300°F) | ASTM C534 |
| Declared Thermal Conductivity λd, 3/8″–2″ Walls (NBR/PVC) at 50°F/75°F/100°F/125°F (10°C/24°C/38°C/52°C) | ≤0.034 / ≤0.0353 / ≤0.037 / ≤0.039 W/(m·K) — k ≤0.235 / ≤0.245 / ≤0.257 / ≤0.268 Btu·in/(h·ft²·°F) | ASTM C177, ASTM C518 |
| Declared Thermal Conductivity λd, 1-1/2″ and 2″ Walls (EPDM) at 50°F/75°F/100°F/125°F (10°C/24°C/38°C/52°C) | ≤0.040 / ≤0.040 / ≤0.041 / ≤0.043 W/(m·K) — k ≤0.278 / ≤0.28 / ≤0.289 / ≤0.300 Btu·in/(h·ft²·°F) | ASTM C177, ASTM C518 |
| R-Value, Tubes (full ID size × wall thickness matrix, 1/4″–2″ wall) | 2.2–19.7, varying by ID size and wall thickness — see manufacturer Technical Bulletin #1 for complete matrix | — |
| R-Value, Sheets and Rolls, 1/4″ (6mm) wall | 1.0 | — |
| R-Value, Sheets and Rolls, 3/8″ (10mm) wall | 1.5 | — |
| R-Value, Sheets and Rolls, 1/2″ (13mm) wall | 2.1 | — |
| R-Value, Sheets and Rolls, 3/4″ (19mm) wall | 3.1 | — |
| R-Value, Sheets and Rolls, 1″ (25mm) wall | 4.2 | — |
| R-Value, Sheets and Rolls, 1-1/2″ (38mm) wall | 6 | — |
| R-Value, Sheets and Rolls, 2″ (50mm) wall | 8 | — |
Flame & Fire Performance
| Property | Value | Test Method |
| Surface Burning Characteristics — AP/ArmaFlex tube (all thicknesses); AP/ArmaFlex FS sheet/roll through 2″; AP/ArmaFlex sheet/roll through 1″ | Flame Spread Index less than 25; Smoke Developed Index less than 50 (AP/ArmaFlex sheet/roll 1-1/2″ and 2″ thickness NOT 25/50 rated) | ASTM E84, UL 723, CAN/ULC S102 |
| FM Approved | Up to 1-1/2″ insulation thickness for tubes and up to 1″ insulation thickness for sheets | FM 49249 |
| UL94 5VA | Pass at 6mm (1/4″) and thicker for AP/ArmaFlex; pass at 7.5mm (0.30″) and thicker for AP/ArmaFlex FS | UL 94, File No. E535094 |
| UL94 V-0 | Pass at 6mm (1/4″) and thicker for AP/ArmaFlex; pass at 13mm (1/2″) and thicker for AP/ArmaFlex FS | UL 94, File No. E535094 |
| UL94 V-1 | Pass at 7.5mm (0.30″) and thicker for AP/ArmaFlex FS | UL 94, File No. E535094 |
| Practical Fire Behavior | Self-extinguishing, does not drip, does not spread flames | UL 94 |
Environmental Performance
| Property | Value | Test Method |
| Water Vapor Permeability (NBR/PVC products) | 0.05 perm-inch (0.725 × 10⁻¹³ kg/(s·m·Pa)) | ASTM E96, Procedure A |
| Water Vapor Permeability (EPDM products) | 0.08 perm-inch (1.16 × 10⁻¹³ kg/(s·m·Pa)) | ASTM E96, Procedure A |
| Mold Growth | Passed | UL 181 |
| Fungal Growth | Passed | ASTM C1338, ASTM G21 |
Acoustic Performance
| Property | Value | Test Method |
| Sound Absorption Average (SAA), 25mm (1″) thickness | 0.38 | ASTM C423, Type A Mounting |
| Sound Absorption Average (SAA), 38mm (1.5″) thickness | 0.49 | ASTM C423, Type A Mounting |
| Sound Absorption Average (SAA), 50mm (2″) thickness | 0.51 | ASTM C423, Type A Mounting |
Compliance
- GREENGUARD Gold Certified
- ISO 9001 — Compliant (Armacell North America quality management systems certified by Intertek)
- ASTM E84, UL 723 — Compliant
- MIL-P-15280J, FORM T — Compliant
- ASHRAE 90.1 energy standards — Compliant
- EPA registered MICROBAN® antimicrobial product protection
- 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; FM 49249)
- CAN/ULC S102 — Compliant (up to 1″ thickness)
- MIL-P-15280J, FORM S — Compliant
- ASTM C534, Type I – Tube Grade 1 — Compliant
- ASTM C534, Type II – Sheet Grade 1 — Compliant
- UL 94 — Compliant (File Number E535094)
- MEA 107-89M — Compliant
- Manufactured without CFCs, HFCs, HCFCs, PBDEs, or Formaldehyde
- ASTM D1056, 2C1 — Compliant
- Conforms to building codes: International Mechanical Code (IMC), International Energy Conservation Code (IECC), International Residential Code (IRC), Title 24 California Building Energy Efficiency Standards
- ASTM G21/C1338 — Compliant
- Condensation control on below-ambient piping and equipment
- Chilled water, refrigeration, and process piping insulation
- HVAC and mechanical duct, pipe, and equipment insulation for energy loss prevention
- Tube, sheet, and roll insulation for commercial and industrial mechanical systems
- High-temperature process piping insulation up to 300°F (149°C) using EPDM-based construction
Common industries: HVAC/mechanical, plumbing and piping, refrigeration, commercial and institutional building construction.
AP/ArmaFlex and AP/ArmaFlex FS are flexible, closed-cell elastomeric insulation products designed for condensation control and energy loss prevention on below-ambient piping and equipment. The closed-cell structure provides inherent resistance to water vapor ingress, so no additional water vapor retarder is required for most applications. AP/ArmaFlex is formulated from nitrile rubber and polyvinyl chloride (NBR/PVC) for insulation up to and including 1″ wall thickness, while AP/ArmaFlex FS and insulation thicknesses greater than 1″ use a PVC-free EPDM formulation, which extends the maximum recommended service temperature to 300°F (149°C) versus 220°F (105°C) for the NBR/PVC construction. Both grades are supplied in tube, sheet, and roll form.
Beyond thermal and vapor performance, both grades demonstrate self-extinguishing, non-dripping fire behavior per UL 94, pass mold growth testing (UL 181) and fungal growth testing (ASTM C1338, ASTM G21), and exhibit low water absorption (0.2% by volume). The products are fiber-free, formaldehyde-free, and manufactured without CFCs, HFCs, HCFCs, or PBDEs, and incorporate EPA-registered MICROBAN® antimicrobial product protection. Sound absorption average (SAA) values of 0.38–0.51 are reported for 1″–2″ thicknesses under Type A mounting. Compliant with ASTM C534 Type I (Tube, Grade 1) and Type II (Sheet, Grade 1), ASTM E84/UL 723, CAN/ULC S102, MIL-P-15280J (FORM S and FORM T), UL 94 (File No. E535094), FM Approvals, MEA 107-89M, ASTM D1056 2C1, ASTM G21/C1338, ASHRAE 90.1, GREENGUARD Gold Certification, and applicable building codes including IMC, IECC, IRC, and Title 24 California Building Energy Efficiency Standards.
What differentiates AP/ArmaFlex from AP/ArmaFlex FS?
AP/ArmaFlex is manufactured from nitrile rubber/PVC (NBR/PVC) for wall thicknesses up to and including 1", while AP/ArmaFlex FS and insulation thicknesses greater than 1" use a PVC-free EPDM formulation. The EPDM-based construction extends the maximum recommended service temperature to 300°F (149°C) compared to 220°F (105°C) for the NBR/PVC construction, and requires greater material thickness to achieve the same UL94 5VA, V-0, and V-1 flame ratings (e.g., UL94 V-0 passes at 6mm/1/4" for AP/ArmaFlex versus 13mm/1/2" for AP/ArmaFlex FS).
Why does water vapor permeability matter for this insulation?
Because the closed-cell structure of AP/ArmaFlex and AP/ArmaFlex FS provides a low water vapor permeability (0.05 perm-inch for NBR/PVC products, 0.08 perm-inch for EPDM products per ASTM E96, Procedure A), the material reliably resists water vapor ingress on below-ambient piping and equipment without requiring an additional vapor retarder for most applications, which directly controls surface condensation and protects insulation performance over time.
What is the service temperature range for AP/ArmaFlex and AP/ArmaFlex FS?
AP/ArmaFlex (NBR/PVC, all wall thicknesses): -297°F to 220°F (-183°C to 105°C). AP/ArmaFlex FS (EPDM, 1-1/2" and 2" walls): -297°F to 300°F (-183°C to 149°C). Per the manufacturer's TDS, flexibility decreases below -20°F (-29°C) without affecting thermal or vapor performance, and applications beyond the recommended range require contacting the manufacturer.
Is AP/ArmaFlex or AP/ArmaFlex FS suitable for flame-rated, regulated mechanical insulation environments?
Yes. Both grades achieve a Flame Spread Index less than 25 and Smoke Developed Index less than 50 per ASTM E84/UL 723 and CAN/ULC S102, are UL 94 rated (File No. E535094, ratings 5VA/V-0/V-1 depending on grade and thickness), are FM Approved (FM 49249) up to specified thicknesses, and meet MIL-P-15280J (FORM S and FORM T), MEA 107-89M, ASTM D1056 2C1, and applicable building codes (IMC, IECC, IRC, Title 24 California Building Energy Efficiency Standards).
How should AP/ArmaFlex or AP/ArmaFlex FS be specified?
Specify grade (AP/ArmaFlex or AP/ArmaFlex FS), wall thickness, ID size or sheet/roll dimensions, compliance requirements, dimensional tolerances, and finished format (tube, sheet, or roll).
