LAC 43:XIII §921
Design of Plastic Pipe [49 CFR 192.121]
(A)A. Design Pressure. The design pressure for plastic pipe is determined in accordance with either of the following formulas.#
where:#
P = Design pressure, gauge, psig (kPa)#
S = For thermoplastic pipe, the HDB is determined in accordance with the listed specification at a temperature equal to 73 ºF (23ºC), 100ºF (38ºC), 120ºF (49ºC), or 140ºF (60ºC). In the absence of an HDB established at the specified temperature, the HDB of a higher temperature may be used in determining a design pressure rating at the specified temperature by arithmetic interpolation using the procedure in Part D.2 of PPI TR-3/2012, HDB/PDB/SDB/MRS Policies", (incorporated by reference, see §507). For reinforced thermosetting plastic pipe, 11,000 psig (75,842 kPa).#
t = Specified wall thickness, in. (mm)#
D = Specified outside diameter, in (mm)#
SDR = Standard dimension ratio, the ratio of the average specified outside diameter to the minimum specified wall thickness, corresponding to a value from a common numbering system that was derived from the American National Standards Institute preferred number series 10.#
DF = Design Factor, a maximum of 0.32 unless otherwise specified for a particular material in this Section. [49 CFR 192.121(a)]#
(B)B. General Requirements for Plastic Pipe and Components [49 CFR 192.121(b)]#
(1)1. Except as provided in Subsections C through F of this Section, the design pressure for plastic pipe may not exceed a gauge pressure of 100 psig (689 kPa) for pipe used in: [49 CFR 192.121(b)(1)]#
(a)a. distribution systems; or [49 CFR 192.121(b)(1)(i)]#
(b)b. transmission lines in Class 3 and 4 locations [49 CFR 192.121(b)(1)(ii)]#
(2)2. Plastic pipe may not be used where operating temperatures of the pipe will be: [49 CFR 192.121(b)(2)]#
(a)a. below -20°F (-29°C), or -40°F (-40°C) if all pipe and pipeline components whose operating temperature will be below -20°F (-29°C) have a temperature rating by the manufacturer consistent with that operating temperature; or [49 CFR 192.121(b)(2)(i)]#
(b)b. above the temperature at which HBD used in the design formula under this Section is determined. [49 CFR 192.121(b)(2)(ii)]#
(3)3. Unless specified for a particular material in this Section, the wall thickness for thermoplastic pipe may not be less than 0.062 in. (1.57 millimeters). [49 CFR 192.121(b)(3)]#
(4)4. All plastic pipe must have a listed HDB in accordance with PPI TR-4/2012). (incorporated by reference, see §507) [49 CFR 192.121(b)(4)]#
(C)C. Polyethylene (PE) Pipe Requirements [49 CFR 192.121(c)]#
(1)1. For PE pipe produced after July 14, 2004, but before January 22, 2019, a design pressure of up to 125 psig may be used, provided: [49 CFR 192.121(c)(1)]#
(a)a. The material designation code is PE2406 or PE3408. [49 CFR 192.121(c)(1)(i)]#
(b)b. The pipe has a nominal size (Iron Pipe Size (IPS) or Copper Tubing Size (CTS)) of 12 inches or less (above nominal pipe size of 12 inches, the design pressure is limited to 100 psig); and [49 CFR 192.121(c)(1)(ii)]#
(c)c. The wall thickness is not less than 0.062 inches (1.57 millimeters). [49 CFR 192.121(c)(1)(iii)]#
(2)2. For PE pipe produced on or after January 22, 2019, a DF of 0.40 may be used in the design formula, provided: [49 CFR 192.121(c)(2)]#
(a)a. the design pressure does not exceed 125 psig; [49 CFR 192.121(c)(2)(i)]#
(b)b. the material designation code is PE2708 or PE4710; [49 CFR 192.121(c)(2)(ii)]#
(c)c. the pipe has a nominal size (IPS or CTS) of 24 inches or less; and [49 CFR 192.121(c)(2)(iii)]#
(d)d. the wall thickness for a given outside diameter is not less than that listed in Table 1 to this Subparagraph C.2.d : [49 CFR 192.121(c)(2)(iv)]#
Table 1 to Subparagraph C.2.d#
PE Pipe: Minimum Wall Thickness and SDR Values#
Pipe Size (inches)#
Minimum Wall Thickness#
Corresponding SDR (values)#
1/2" CTS#
0. 090#
7#
1/2" IPS#
0. 090#
9. 3#
3/4" CTS#
0. 090#
9. 7#
3/4" IPS#
0. 095#
11#
1" CTS#
.099#
11#
1" IPS#
0. 119#
11#
1 ¼" CTS#
0. 121#
11#
1 1/4" IPS#
0. 151#
11#
1 1/2" IPS#
0. 173#
11#
2"#
0. 216#
11#
3"#
0. 259#
13. 5#
4"#
0. 265#
17#
6"#
0. 315#
21#
8"#
0. 411#
21#
10"#
0. 512#
21#
12"#
0. 607#
21#
16#
.762#
21#
18#
.857#
21#
20#
.952#
21#
22#
1. 048#
21#
24#
1. 143#
21#
(D)D. Polyamide (PA-11) Pipe Requirements [49 CFR 192.121(d)]#
(1)1. For PA-11 pipe produced after January 23, 2009, but before January 22, 2019, a DF of 0.40 may be used in the design formula, provided: [49 CFR 192.121(d)(1)]#
(a)a. the design pressure does not exceed 200 psig; [49 CFR 192.121(d)(1)(i)]#
(b)b. the material designation code is PA32312 or PA32316; [49 CFR 192.121(d)(1)(ii)]#
(c)c. the pipe has a nominal size (IPS or CTS) of 4 inches or less; and [49 CFR 192.121(d)(1)(iii)]#
(d)d. the pipe has a standard dimension ratio of SDR-11 or less (i.e., thicker wall pipe). [49 CFR 192.121(d)(1)(iv)]#
(2)2. For PA-11 pipe produced on or after January 22, 2019, a DF of 0.40 may be used in the design formula, provided: [49 CFR 192.121(d)(2)]#
(a)a. the design pressure does not exceed 250 psig; [49 CFR 192.121(d)(2)(i)]#
(b)b. the material designation code is PA32316; [49 CFR 192.121(d)(2)(ii)]#
(c)c. the pipe has a nominal size (IPS or CTS) of 6 inches or less; and [49 CFR 192.121(d)(2)(iii)]#
(d)d. the minimum wall thickness for a given outside diameter is not less than that listed in Table 2 to Subparagraph D.2.d . [49 CFR 192.121(d)(2)(iv)]#
Table 2 to Suparagraph D.2.d#
PE Pipe: Minimum Wall Thickness and SDR Values#
Pipe Size (inches)#
Minimum Wall Thickness#
Corresponding SDR (values)#
1/2" CTS#
0. 090#
7. 0#
1/2" IPS#
0. 090#
9. 3#
3/4" CTS#
0. 090#
9. 7#
3/4" IPS#
0. 095#
11#
1" CTS#
0. 119#
11#
1" IPS#
0. 119#
11#
1 1/4 IPS#
0. 151#
11#
1 1/2" IPS#
0. 173#
11#
2" IPS#
0. 216#
11#
3" IPS#
0. 259#
13. 5#
4" IPS#
0. 333#
13. 5#
6" IPS#
0. 491#
13. 5#
(E)E. Polyamide (PA-12) Pipe Requirements [49 CFR 192.121(e)]#
(1)1. For PA-12 pipe produced after January 22, 2019, a DF of 0.40 may be used in the design formula, provided: [49 CFR 192.121(e)(1)]#
(a)a. the design pressure does not exceed 250 psig; [49 CFR 192.121(e)(1)(i)]#
(b)b. the material designation code is PA42316; [49 CFR 192.121(e)(1)(ii)]#
(c)c. the pipe has a nominal size (IPS or CTS) of 6 inches or less; and [49 CFR 192.121(e)(1)(iii)]#
(d)d. the minimum wall thickness for a given outside diameter is not less than that listed in Table 3 to Subparagraph E.1.d [49 CFR 192.121(e)(1)(iv)]#
Table 3 to Subparagraph E.1.d#
PE Pipe: Minimum Wall Thickness and SDR Values#
Pipe Size (inches)#
Minimum Wall Thickness#
Corresponding SDR (values)#
1/2" CTS#
0. 090#
7#
1/2" IPS#
0. 090#
9. 3#
3/4" CTS#
0. 090#
9. 7#
3/4" IPS#
0. 095#
11#
1" CTS#
0. 119#
11#
1" IPS#
0. 119#
11#
1 1/4" IPS#
0. 151#
11#
1 1/2" IPS#
0. 173#
11#
2" IPS#
0. 216#
11#
3" IPS#
0. 259#
13. 5#
4" IPS#
0. 333#
13. 5#
6" IPS#
0. 491#
13. 5#
(F)F. Reinforced Thermosetting Plastic Pipe Requirements [49 CFR 192.121(f)]#
(1)1. Reinforced thermosetting plastic pipe may not be used at operating temperatures above 150 °F (66 °C). [49 CFR 192.121(f)(1)]#
(2)2. The wall thickness for reinforced thermosetting plastic pipe may not be less than that listed in the following table. [49 CFR 192.121(f)(2)]#
Nominal Size in Inches (Millimeters)#
Minimum Wall Thickness Inches (Millimeters)#
2 (51)#
0. 060 (1.52)#
3 (76)#
0. 060 (1.52)#
4 (102)#
0. 070 (1.78)#
6 (152)#
0. 100 (2.54)#
AUTHORITY NOTE: Promulgated in accordance with R.S. 30:501 et seq.#
HISTORICAL NOTE: Promulgated by the Department of Natural Resources, Office of Conservation, LR 9:222 (April 1983), amended LR 10:515 (July 1984), LR 24:1308 (July 1998), LR 27:1538 (September 2001), LR 30:1231 (June 2004), LR 31:682 (March 2005), LR 33:478 (March 2007), LR 35:2804 (December 2009), LR 38:115 (January 2012), repromulgated LR 38:828 (March 2012), amended LR 44:1037 (June 2018), LR 46:1582 (November 2020), LR. 47:1141 (August 2021), LR 49:1103 (June 2023), amended by the Department of Conservation and Energy, Office of Enforcement, LR 51:1831 (November 2025).#