1、RECOMMENDATION B 1997THERMOPLASTIC PIPINGFOR THE TRANSPORT OF COMPRESSED AIROR OTHER COMPRESSED GASESOriginally Adopted January, 1972Revised December 30, 2005The evaluation of thermoplastic piping for compressed gas service shouldconsider all pertinent design and safety factors. Chemical effects oxi
2、dation andtemperature should be taken into account. The Plastics Pipe Instituterecommends that thermoplastics piping intended for the transport of compressedair or other compressed gases should be installed by burial, encasement inshatter resistant material, or other appropriate means, to prevent or
3、 minimize thepossibility of mechanical damage.Thermoplastic piping that fails from mechanical impact by shattering or whippingcan be hazardous to personnel. The potential safety hazard posed by failuremust take into consideration the nature of the material, internal pressure, pipesize, and the natur
4、e of the gas.Aboveground installations of thermoplastic piping should be installed per themanufacturers recommendations using only products that are recommended bythe manufacturer for the particular intended service. Some thermoplastic pipematerials have limited resistance to shatter-type failures f
5、rom mechanical impact.Suddenly released compressed gas can propel pipe shards or fragments.Materials that can fail by shattering pose a hazard to employees if they areinstalled above ground without encasement or other protection.Other thermoplastic materials that resist shattering, may be sufficiently flexiblethat if there is a failure or separation of the piping the piping can whip aboutuncontrollably as the pipe is propelled by the energy of the suddenlydecompressing gas. Flexible aboveground piping should be properly restrainedto prevent or limit whipping of the piping material.
