TEMPERATURES & PRESSURES
The maximum safe pressure for a given plastic pipe is determined by the pipe's wall thickness and Hydrostatic Design Basis (HDB),
the plastic pipe industry's pressure rating method. The resultant maximum safe pressure is the modified by a design factor
established by the Department of Transportation to arrive at a design pressure rating.
| Plastic Material |
Design Factor |
| Polyethylene (PE) |
0.32 |
| Polyamide 11 (PA11) |
0.40 |
By federal code the design pressure for a polyethylene gas line may not exceed 100 psig with some exceptions.
These exceptions allow for the use of PE 2406 or PE3408 polyethylene gas pipe produced after July 14, 2004 up to
125 psig up through nominal 12" diameter pipe.
Polyamide 11 in diameters up to 4" IPS may operate at pressures up to 200 psi also in accordance with federal code.
For more information please see Gas Industry
Links.
PE pipe's operating temperature range is from -20°F to 140°F in pressure service. The U.S. Department of Transportation
suggests that systems and fittings not be operated above 100°F unless components have demonstrated that gas can be
safely transported at the higher temperature and expected pressure. PA 11 and PEX pipe may be operated up to 200°F,
which make them attractive for higher temperature applications, such as gas lines installed close to steam lines.
Cold ambient temperature does not have an adverse effect on plastic pipe strength or characteristics.
