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ASME B31.3-2016 (b) Metallic Piping With Nonmetallic Lining. Allow- shall be one-tenth of the minimum tensile strengths spec- ances for pressure and temperature variations provided ified in ASTM C582 and are valid only in the temperature in para. 302.2.4 are permitted only if the suitability of range from —29°C (-20°F) through 82°C (180°F). the lining material for the increased conditions is estab- (c) Reinforced Thermosetting Resin and Reinforced Plastic fished through prior successful service experience or Mortar (Filament Wound and Centrifugally Cast). The tests under comparable conditions. hydrostatic design basis stress(HDBS)values for materi- als listed in Table B-3 shall be obtained by the procedures A302.2.5 Rating at Junction of Different Services. in ASTM D2992 and are valid only at 23°C (73°F). HDS When two services that operate at different pressure— shall be obtained by multiplying the HDBS by a service temperature conditions are connected, the valve segre- (design) factor selected for the application, in accor- gating the two services shall be rated for the more severe dance with procedures described in ASTM D2992, service condition. within the following limits: A302.3 Allowable Stresses and Other Design Limits (1) When using the cyclic HDBS, the service (design) factor F shall not exceed 1.0. A302.3.1 General (2) When using the static HDBS, the service (a) Table B-1 contains hydrostatic design stresses (design) factor F shall not exceed 0.5. (HDS). Tables B-2 and B-3 provide listings of specifica- (d) Other Materials. Allowable pressures in Tables B-4 tions that meet the criteria of paras. A302.3.2(b) and and B-5 have been determined conservatively from (c), respectively. Tables B-4 and B-5 contain allowable physical properties of materials conforming to the listed pressures. These HDS values, allowable stress criteria, specifications, and have been confirmed by extensive and pressures shall be used in accordance with the Notes experience. Use of other materials shall be qualified as to Appendix B,and may be used in design calculations required by para. A304.7.2. (where the allowable stress S means the appropriate A302.3.3 Limits of Calculated Stresses Due to design stress)except as modified by other provisions of Sustained Loads 1 this Code.Use of hydrostatic design stresses for calcula- (a) Internal Pressure Stresses. Limits of stress due to tions other than pressure design has not been verified. internal pressure are covered in para. A304. The bases for determining allowable stresses and pres- (b) External Pressure Stresses. Stresses due to uniform sures are outlined in para. A302.3.2. external pressure shall be considered safe when the wall (b) The stresses and allowable pressures are grouped thickness of the component and its means of stiffening by materials and listed for stated temperatures.Straight- have been qualified as required by para. A304.7.2. line interpolation between temperatures is permissible. (c) External Loading Stresses. Design of piping under (16) A302.3.2 Bases for Allowable Stresses and external loading shall be based on the following: Pressures 1 (1) Thermoplastic Piping. ASTM D2321 or (a) Thermoplastics. The method of determining HDS AWWA C900. is described in ASTM D2837. HDS values are given in (2) Reinforced Thermosetting Resin (RTR) and Table 13-1 for those materials and temperatures for which Reinforced Plastic Mortar(RPM)Piping. ASTM D3839 or sufficient data have been compiled to substantiate the Appendix A of AWWA C950. determination of stress. (3) Strain and possible buckling shall be considered (b) Reinforced Thermosetting Resin (Laminated). The when determining the maximum allowable deflection design stress(DS)values for materials listed in Table B-2 in (1) or (2) above, but in no case shall the allowable diametral deflection exceed 5% of the pipe inside diameter. 1 Titles of ASTM Specifications and AWWA Standards referenced (4) Nonmetallic piping not covered in (1) or (2) herein are as follows: above shall be subjected to a crushing or three-edge ASTM C14,Concrete Sewer,Storm Drain,and Culvert Pipe ASTM C301,Method of Testing Vitrified Clay Pipe bearing test in accordance with ASTM C14 or C301; ASTM C582, Contact-Molded Reinforced Thermosetting Plastic the allowable load shall be 25% of the minimum value (RTP)Laminates for Corrosion Resistant Equipment obtained. ASTM D2321, Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow A302.3.4 Limits of Calculated Stresses Due to Applications Occasional Loads ASTM D2837,Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for (a) Operation. The sum of the stresses in any compo- Thermoplastic Pipe Products nent in a piping system due to sustained loads,such as ASTM D2992, Practice for Obtaining Hydrostatic or Pressure Design Basis for"Fiberglass"(Glass-Fiber-RTR)Pipe and Fittings z The service(design)factor,F,should be selected by the designer ASTM D3839,Underground Installation of Fiberglass Pipe after evaluating fully the service conditions and the engineering AWWA C900,PVC Pressure Pipe,4-inch through 12-inch,for Water properties of the specific material under consideration.Aside from AWWA C950, Glass-Fiber-Reinforced Thermosetting Resin the limits in paras.A302.3.2(c)(1)and(2),it is not the intent of this Pressure Pipe Code to specify service(design)factors.