The primary limitation of PVC material is the recommended environmental temperature limit of 140° F (60°C).
Maximum operating and required minimum bursting pressures at 73oF (23oC) for PVC pipe fittings according ASTM D1785 Standard Specification for Poly Vinyl Chloride (PVC) Plastic Pipes Schedules 40 and 80 are indicated in the diagram and table below: Note! The maximum operating pressures derates with temperature. At the maximum operating temperature for PVC - 140oF (60oC) - the strength is derated to approximately 20% of the strength at 73oF (23oC) . Be aware that maximum operating pressures varies with the fittings design. Consult the manufacturing data. Mechanical properties of PVC are temperature dependent. Nominal working pressures are determined at 20°C. For lower operating temperatures, the 20°C ratings are used, even though properties such as tensile strength are greater. As the temperature decreases, it is advisable to take additional care to avoid impact damage as the impact strength decreases with temperature. The coefficient of thermal expansion is 7 x 10 -5 /°C. A handy rule is 7 mm change in length for every 10 metres for every 10°C change in temperature. Example. A 150 metre line of PVC pipe is being installed with the temperature at 28°C. The service temperature will be 18°C. Pressure Rating. At temperatures below 20°C, the resistance to internal pressure of a PVC pipe increases as the strength of the PVC material increases. However, it is not customary to utilise this increase in strength by increasing the pressure rating. The nominal pressure rating of the pipe at 20°C, or PN, should still define the maximum allowable operating pressure at lower temperatures. At temperatures above 20°C the maximum allowable operating pressure must be reduced in proportion to the material strength. Use of PVC pipes in the temperature range from 20°C up to the recommended maximum continuous operating temperature of 60°C is well defined (for more information see PVC Temperature Considerations). However, it is not customary to utilise this increase in strength by increasing the pressure rating. The nominal pressure rating of the pipe at 20°C, or PN, should still define the maximum allowable operating pressure at lower temperatures. Although Type I PVC can be satisfactorily used for many applications at temperatures of up to 140° F, its strength and creep characteristics are altered. CPVC shall carry a maximum operating temperature of 200° F and has the same self-extinguishing and low conductivity features as PVC. Share This: The primary limitation of PVC material is the recommended environmental temperature limit of 140° F (60°C). This limit is not only a structural strength limitation but also a corrosion resistance limitation. Both can decrease rapidly as the temperature increases. Maximum Service Temperature. PVC-U and PVC-M pressure pipes are suitable for use at service temperatures up to 50°C. For PVC-O pipes, the maximum continuous operating temperature should be limited to 45°C. The coefficient of thermal expansion is 7 x 10 -5 /°C. A handy rule is 7 mm change in length for every 10 metres for every 10°C change in temperature. Example. A 150 metre line of PVC pipe is being installed with the temperature at 28°C. The service temperature will be 18°C. Example-Higher Temperature and Reduced Strength. If operating pressure for a 6 Schedule 80 CPVC pipe is 167 psi, the maximum operating pressure at 150 oF (66 oC) is reduced to. (167 psi) 0.5. = 83.5 psi. 1 Temperature Derating of Steel Pipes-Temperature derating factor of steel pipes. 2  Plastic Pipes and Operating Temperatures-ABS, PE, PVC, CPVC, PB, PP and SR-Operating temperatures with or without pressure. 3  PVC Pipes-Pressure Ratings-Maximum operating and required burst pressure of PVC-Polyvinyl Chloride-pipe fittings. A good rule of thumb in design of PVC pipe and conduit systems is to allow 3/8” length variation for every 100 feet of pipe for each 10°F change in temperature. (This rule is independent of pipe size.) Table 1 can also be used to determine the effects of temperature changes on the length of PVC pipe and conduit. To reduce the pressure ratings of PVC pres-sure pipe for operating temperatures above 73°F, mul-tiply the pressure rating or pressure class by the derat-ing factors in Table 2 on the back of this page. JANUARY 2009 TECHNICAL BULLETIN Building essentials for a better tomorrow.
http://www.engineeringtoolbox.com/pvc-cpvc-pipes-pressures-d_796.html http://www.vinidex.com.au/technical/pvc-pressure-pipe/pvc-temperature-considerations/ http://www.vinidex.com.au/technote-parent-page/pvc-pipes-in-low-temperature-applications/ http://www.vinidex.com.au/technote-parent-page/pvc-pipes-in-low-temperature-applications/ http://www.usplastic.com/knowledgebase/article.aspx?contentkey=796 http://www.vinidex.com.au/technical/pvc-pressure-pipe/pvc-temperature-considerations/ http://www.engineeringtoolbox.com/thermoplastic-pipes-temperature-strength-d_794.html http://www.jmeagle.com/pdfs/Technical%20Bulletins/TB09TempEffectsonPVC.pdf
temp rating for pvc