The Plastic Pipe Institute has issued the following "Use Recommendation" for Polyethylene Piping systems for LPG and it's major component, propane gas. (Technical Report PPI-TR22 - July 1974)

The information collected indicates that polyethylene piping is satisfactory for transporting LPG a+nd it's major component, propane gas. The information also indicates that pressure design parameters based on propane gas should be adequate and reasonable. However, until more information is available, these recommendations cover only commercial propane in detail.

These use recommendations cover polyethylene plastic pipe for commercial propane gas systems that serve over 10 or more customers, or for systems, any portion of which is located in a public place, such as a highway.

1. The polyethylene pipe, tubings and fittings should be only those specific types designated as PE-2406 or PE-3408 and meeting the appropriate requirements of ASTM D2513
2. A long term hydrostatic strength (design basis) of 1000 psi should be used in the design of polyethylene piping systems for commercial propane gas distribution at pipe temperatures of 73°F or lower. The long-term hydrostatic strength measurements should be made in accordance with ASTM D2837
3. Polyethylene piping should be used only in underground commercial propane gas distribution systems designed to operate at internal pressures and temperatures such that condensation will not occur.
   These conditions are as follows: