Polyurethane Flexible Membrane Liners
Secondary Containment Applications
In the petroleum business, there are hundreds of thousands of underground and above-ground fuel storage tanks. State regulations and insurance requirements demands that every tank be surrounded by a second container. It is recommended in many cases that be a flexible membrane excavation liner, which is relatively low in cost. It is independent of the main containment and able to withstand much of the ground movement, which causes rigid container to leak in the first place. The same is true for the miles of piping that lead to these underground storage sites.
Throughout the industry, the above and below ground storage of process chemicals, maintenance supplies, bulk chemicals, fertilizers, and other “hazardous” substances are under mandate to be contained with both primary and back-up systems. Polyurethane flexible membrane is doing the job and beyond what the standards have set.
Polyurethane is a flexible membrane liner primarily designed for the secondary containment of fuel. Polyurethane is extremely flexible, puncture resistant, and provides unusually good heat-sealing characteristics. Polyurethane is protected from ultraviolet degradation and the effect of underground fungi. Polyurethane is strong and hydrolytically stable for years of service in underground fuel and chemical.
POLYURETHANE
PHYSICAL PROPERTY SPECIFICATIONS
| POLYURETHANE | STANDARD | METRIC |
| Base Fabric Type | Nylon | Nylon |
| Base Fabric Weight (nominal) | 13.0 oz/yd² | 441 g/m² |
| Coating Type | Polyester based Polyurethane | Polyester based Polyurethane |
| Finished Coated Weight ASTM D751 |
32 oz/yd²
± 2 oz/yd² |
1085 g/m²
± 70 g/m² |
| Thickness ASTM D751 |
35 mil (nominal) | 0.89 mm (nominal |
| Grab Tensile ASTM D751 |
1000/1000 lbf (min) | 4450/4450 N (min |
| Strip Tensile ASTM D751 Procedure B |
600/600 lbf/in (min) | 526/526 daN/5 cm (min) |
| Adhesion ASTM D751 Dielectric Weld |
50 lbf/in (min) | 45 daN/5 cm (min) |
| Hydrostatic Resistance ASTM D751 Procedure A |
1500 psi (min) | 10.3 MPa (min) |
| Bursting Strength ASTM D 751 (Ball Tip) |
1200 lbf (min) | 5340 N (min) |
| Low Temperature ASTM D2136 |
1/8 in mandrel, 4hr Pass @ -50ºF |
3.2 mm mandrel, 4 hr Pass @ -46ºC |
| Dead Load ASTM D751 PASS @ |
2 inch Seam, 4 hr, 1inch strip
250 lbf @ Room Temp 125 lbf @ 160ºF |
5 cm Seam, 4 hr, 2.5 cm strip
1113 N @ Room Temp 556 N @ 71ºC |
| Abrasion Resistance ASTM D3389 H-22 wheel/1000g load |
10,000 cycles minimum before fabric exposure |
10,000 cycles minimum before fabric exposure |
| Permeability ASTM D814 (Fuel B) |
0.05 fl. oz/ft²/24 hr (max) | 15.9 mL/m²/24 hr (max) |