1、Suggested Temperatu re Limits for the Operation and Installation of Thermoplastic Piping in Non- Pressure Applications TN-I 1/99 Foreword This report was developed and published with the technical help and financial support of the members of the PPI (Plastics Pipe Institute, Inc.). The members have
2、shown their interest in quality products by assisting independent standards-making and user organizations in the development of standards, and also by developing reports on an industry-wide basis to help engineers, code officials, specifying groups, and users. The purpose of this technical note is t
3、o provide suggested temperature limits for the operation and installation of thermoplastic piping in non-pressure applications. This report has been prepared by PPI as a service of the industry. The information in this report is offered in good faith and believed to be accurate at the time of its pr
4、eparation, but is offered without any warranty, expressed or implied, including WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Any reference to or testing of a particular proprietary product should not be construed as an endorsement by PPI, which does not endorse the proprietary
5、 products or processes of any manufacturer. The information in this report is offered for consideration by industry members in fulfilling their own compliance responsibilities. PPI assumes no responsibility for compliance with applicable laws and regulations. PPI intends to revise this report from t
6、ime to time, in response to comments and suggestions from users of the report. Please send suggestions of improvements to the address below. Information on other publications can be obtained by contacting PPI directly or visiting the web site. The Plastics Pipe Institute Toll Free: (888) 314-6774 De
7、cem ber 1999 SUGGESTED TEMPERATURE LIMITS FOR THE OPERATION AND INSTALLATION OF THERMOPLASTIC PIPING IN N ON - P RES S U RE AP P LI CATI ON S Operating Notes: The following related information and precautions should be considered before thermoplastic non-pressure piping systems are designed to trans
8、port fluids at the high temperature limits suggested in this document. It may be advisable in some cases to reduce these maximum temperature limits due to the chemical compatibility between the fluid and the piping material. For purposes of this document, non-pressure piping systems should be consid
9、ered those piping systems which do not operate fully charged for their continuous length and for which the static head never exceeds 15 psig. Some plastic pipe systems may be affected by the continuous exposure to higher temperature fluids. Pipe and fitting manufacturers should be consulted for info
10、rmation about the effects of fluid temperatures on the piping system and its operation. It should be noted that given the lower thermal conductivity of thermoplastics, the outer surface of the pipe might be at a lower temperature than the hotter fluid inside the pipe. The maximum temperatures sugges
11、ted in the table are for the fluids being transported. The suggested temperature limits, which have been established under the assumption that the outer pipe surface is exposed to ambient temperatures, may need to be modified for cases where this assumption is essentially incorrect such as buried or
12、 insulated pipe. While the guidelines presented in the table are generally accepted for the products described, not all piping compounds are designed to sustain continuous exposure to high temperatures. The piping manufacturer should be consulted for specific information regarding thermal and oxidat
13、ive stability of the piping product being provided. The materials included in the tables are those covered by the current ASTM standards. Material or pipe manufacturers should be consulted for recommendations about other piping materials. The temperature limits presented here are based on non-pressu
14、rized continuous exposure to high temperature aqueous environment. The piping manufacturer should be consulted regarding the applicability of these limits in the presence of specific chemicals or conditions. Above ground installations, in which a polyolefin piping system conveys fluids at more tradi
15、tional temperatures but is in direct exposure to sunlight for extended periods of time is of equal concern. In these situations, a conservative design and operating philosophy, in which continual exposure to the high temperature extremes associated with heating by sunlight of the piping system, is r
16、ecommended. Installation Notes When solvent cement joints are made at temperatures below 32“F, special precautions are needed to obtain adequate joint strength. Additional drying time may be required for solvent cement permeation and cure time of the joint. Refer to ASTM D2855 and/or consult piping
17、manufacturers for details. Solvent cement manufacturers should be consulted regarding precautions that should be taken at the temperature extremes indicated. Transporting fluids near the maximum temperature limit may require a continuously supported pipeline. For lower temperatures and intermittent
18、flow it may be acceptable to support the pipe with hangers spaced at appropriately close intervals. The reader is referred to PPIs Handbook of Poyefhyene for more information on this subject. Joining of polyolefin pipe under the extreme temperatures presented in the tables may require special consid
19、eration and handling. Fusion joining of polyolefin pipe at these temperature extremes may require sheltering of the fusion apparatus and the fusion crew. Handling of any construction materials at the temperature extremes presented in the tables should be done with extreme caution. Any pipe or fittin
20、g left in direct sunlight at very high ambient temperatures will increase in temperature significantly. Caution should be exercised in handling pipe and fittings in these situations so as to avoid any potential for personal injury. The effects of low temperature are different. As temperatures drop,
21、the modulus of elasticity for most polyolefins increases thus increasing the potential of low-temperature embrittlement. As such, polyolefin piping should handled in accordance with specific manufacturers recommendations at these low temperature extremes. SUGGESTED TEMPERATURE LIMITS FOR OPERATION A
22、ND INSTALLATION OF THERMOPLASTIC PIPE I N N ON-PRESSU RE APPLICATIONS Min i mum Temperature For Non-Pressure Pipe Material Continuous Flow (OF) Acry lo n i tri le Bu tad i en e O Styrene (ABS) Polyethylene (PE) PE1404 PE2406 PE3408 -40 -40 -40 Crosslinked Polyethylene (PEX) -30 Polyvinyl Chloride (P
23、VC) C h I or i n a ted Po I yv i n y I Chloride (CPVC) Polybutylene (PB) Pipe Material Acrylonitrile Butadiene Styrene (ABS) Polyethylene (PE) PE1404 PE2406 PE3408 O O O Minimum Installation Temperature (OF) O -30 -30 -30 Crosslinked Polyethylene (PEX) -30 Polyvinyl Chloride (PVC) O C h I or i n a ted Po I yv i n y I Chloride (CPVC) O Polybutylene (PB) O Maximum Temperature for Non-Pressure Continuous Flow (OF) 180 1 O0 180 180 21 o 150 21 o 21 o Maximum Installation Temperature (OF) 120 130 130 130 140 120 140 120 Copyright, The Plastics Pipe Institute, Inc. 1999
