1703.4 Underground Piping and Submerged Materials

1703.4 Underground Piping and Submerged Materi- als. Underground and submerged piping for a ground-heat exchanger shall be polyethylene (PE) pipe or tubing in accordance with Section 1703.4.1 and Section 1703.4.1.1, or crosslinked polyethylene (PEX) pipe or tubing in accordance with Section 1703.4.2 and Section 1703.4.2.1.

1703.4.1 Polyethylene (PE). Polyethylene pipe or tubing shall be manufactured in accordance with the standards listed in Table 1703.2. Pipe or tubing shall have a minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).

Polyethylene pipe and tubing shall be manufactured from a PE compound that has a pipe material designation code of PE 3608, PE 3708, PE 3710, PE 4608, PE 4708, or PE 4710 as defined in the applicable standards referenced in Table 1703.2, with a cell classification in accordance with ASTM D3350 appropriate for the material designation code, and a color and ultraviolet stabilizer code of C or E. Code E compounds shall be stabilized against deterioration from unprotected exposure to ultraviolet rays for not less than 3 years in accordance with the test criteria specified in ASTM D2513.

1703.4.1.1 Joining Methods for Polyethylene Pipe or Tubing. Joints between high density polyethylene (HDPE) plastic pipe or tubing and fittings shall be installed in accordance with the manufac

TABLE 1701.11.1

WATER QUALITY [1]

WATER QUALITY TABLE 1703.3

GROUND SOURCE LOOP PIPE FITTINGS

PARAMETER	ACCEPTABLE RANGE
Ammonium	< 2 ppm
Chlorides2	< 125 ppm
(Free CO2)3	< 50 ppm
pH	7.0 – 8.5
Sulphates	< 125 ppm
TDS	10 – 1000 ppm
Total Hardness	< 150 ppm

Notes: 1 Where chemical additives are used, the acceptable ranges provided shall be in accordance with the equipment manufacturer’s specifications, or this table, whichever is more stringent. 2 The provided acceptable range for chlorides is dependent upon the system heat exchanger and piping materials. See the manufacturer’s specifications for equipment and materials used. 3 The limit provided pertains to makeup water.

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turer’s installation instructions, the appropriate standards listed in accordance with Table 1703.3, and one of the following heat fusion methods:

(1) Butt-fusion joints shall be made in accordance with ASTM F2620.

(2) Socket-fusion joints shall be made in accordance with ASTM F2620.

(3) Electrofusion joints shall be made in accordance with ASTM F1055.

1703.4.2 Polyethylene of Raised Temperature (PE-RT). Polyethylene of raised temperature tubing shall be manufactured in accordance with the standards

listed in Table 1703.2. Tubing shall have a minimum wall thickness equal to SDR 9 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).

Polyethylene of raised temperature tubing shall be manufactured from a PE compound that has a pipe material designation code of PE 2708, PE 3608, or PE 4710 as defined in the applicable standards referenced in Table 1703.2, with a cell classification in accordance with ASTM D3350 appropriate for the material designation code.

1703.4.2.1 Joining Methods for Polyethylene of Raised Temperature (PE-RT). Joints between polyethylene of raised temperature (PE-RT) tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions and the

appropriate standards listed in accordance with Table 1703.3.

1703.4.3 Cross-Linked Polyethylene (PEX). Crosslinked polyethylene pipe shall be manufactured in accordance with the standards listed in Table 1703.2. PEX

shall have a minimum tubing material designation code of PEX 1206 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).

1703.4.3.1 Joining Methods for Cross- Linked Polyethylene Tubing. Joints between cross-linked polyethylene (PEX) pipe or tubing and fittings shall be installed in accordance with the manufacturer’s installation instructions and the

appropriate standards in accordance with Table 1703.3.