The duct, encased either in concrete or buried directly below a concrete slab, is installed above the original line of undisturbed soil and above the water table. Encasing the duct in concrete with porous fill beneath is the best way to install Spiral vinyl-coated duct. An optional vapor barrier can be placed between the pipe and the fill.

These are only basic guidelines; you must check your local building codes for more specific installation instructions.

PVS Information

PVS spiral pipe is UL listed and manufactured from prime hot dipped galvanized steel coated with polyvinyl chloride material, with an outside thickness of 4-mil and inside 1-mil, standard. This is reversible for special purposes.  For extreme duty applications a 4x4 coating is applied. External corrugations are standard for 14" diameters and over for underground applications. Standard gauges are 4" to 16"/24 gauge, 17" to 24"/22 gauge, 26" to 48"/20 gauge. Our PVS coated class I duct has a temperature range of -40 F to 250 F and should not exceed 3600 fpm with positive and negative pressure limits not in excess of 6 inches water column. For more detailed specifications, click here.

PVS Compliance data
Spiral Manufacturing Co., Inc. PVS products comply with the following codes and industry standards:
UL 181 Class 1
International Mechanical Code - 1996 Section 603
BOCA National Mechanical Code - 1993
ICBO Uniform Mechanical Code - (UMC) 1997
SMACNA Sheet Metal Air Conditioning Contractors National Association