Energy Tech Laboratories Homes Northwest manual Type II density, 0.91 to 0.92 g/cm

1.6.4Specification of Polyethylene pipe will be by cell classification number. The specification for PE pipe shall be as follows:

"Polyethylene pipe furnished under this specification shall be manufactured in accordance with dimensional specifications of ASTM D-2513 or ASTM F-714, as appropriate, using a resin having a cell classification of ######Z as defined by ASTM D-3350. This resin shall exhibit not more than 20% failures (F20%) when tested for 192 or more hours under ASTM D-1693, Condition C.

1.6.5The minimum cell classification number acceptable for polyethylene pipe is PE3455434C or PE355434C when tested under ASTM D-3350.

1.6.6The specification for PB pipe shall be as follows:

Polybutylene pipe furnished under this specification shall be manufactured in accordance with ASTM Standard ASTM D-2581. The material shall be:

1.6.6.1Either Class B (general purpose and dielectric, in colors) or Class C (weather resistant, black in color containing not less than 2% carbon black).

1.6.6.2.Type II (density, 0.91 to 0.92 g/cm).

1.6.6.3Grade 1. (Low rate 0.25 to 0.75 g/10 min).

For fusible pipe, dimensional standards are given by ASTM D 2666 and

D3000.

1.7Pipe Joining methods

1.7.1The only acceptable method for joining buried pipe systems is by a heat fusion process. No other method is acceptable.

1.7.2For polyethylene pipe, butt fusion is recommended.

1.7.3For polybutylene pipe, socket fusion is recommended.

1.8Flushing, Purging, Pressure and Flow Testing

1.8.1Vertical loops will be pressure tested before installation.

1.8.2All horizontal components of the ground heat exchanger will be flushed, pressure and flow tested prior to backfilling.

1.8.3Heat exchangers will be tested hydrostatically at 150% of the pipe design rating, or 300% of the system operating pressure if this value is the smaller of the two.

ENERGY STAR Homes Northwest 3

Geothermal Heat Pump Design and Installation Standards