Geothermal HDPE Poly-Pipe

Geothermal pressure pipe is used for low pressure industrial, watertight, mining, environmental, and drainage applications. It is a high density, extra high molecular weight pressure piping system that is often used in geothermal heating. The pipe is buried in the ground, and allows heat transfer between the fluid in the pipe and the ground. 

Geothermal HDPE innerduct is generally made to order. Contact us for lead times or request a quote for more information. Other styles of HDPE pipe are also available.

IGSHPA recommends HDPE pipe for these properties:

• Corrosion Resistant
• Chemical Resistant
• Flexible & Tough
• Thermal Conductivity
• Fusion-welded Leak Tight Joints

Table values are within ASTM tolerances.
BDI PE 4710 pipe will have higher Pressure Class (PC) for the same DR as compared to PE 3408/3608 pipe. Contact the BDI technical staff for pressure values.

INSTALLATION
Refer to IGSHPA Installation Manual for Geothermal Systems and PPI’s “Handbook of Polyethylene Pipe” for installation guidelines of pipe and grouting methods. After installation, but before backfilling, the pipe should be flushed, purged and hydrostatically pressure tested to make certain there were no installation or shipment damages.

GENERAL GUIDELINES

• Calculate total working pressure of the system and check it does not exceed the performance capabilities of the pipe and fittings. (*Pressure Class ratings listed are calculated at 73°. Operating temperatures above 73° will have lower pressure ratings. Consult the PPI “Handbook of Polyethylene Pipe” for Temperature Compensation Multipliers.)
• Inspect pipe when delivered and before installation to identify any damage that might have occurred in shipment or handling.
• When installing in a trench, ensure the bedding and backfill are smooth and free from debris and rocks. Install the pipe in accordance with IGSHPA guidelines and ASTM D 2774 - “Underground Installation of Thermoplastic Pressure Pipe.” When installing in a bore hole, make sure any ballast used will not damage piping.

U-BENDS
Geothermal Pipe Coils can be supplied with U-Bends (180 degree elbows) installed by the manufacturer, thus eliminating a field weld. Coils consist of the supply and return loop in parallel with the U-Bend welded at one end. U-Bend coils are generally supplied with 5’of extra pipe on each supply and return loops to facilitate connection to the header. Geothermal pipe is also supplied in basic coil lengths or 20 foot sticks for custom applications.

JOINING
Geothermal Pipe is manufactured according to ASTM D 3035 dimensions based on IPS (Iron Pipe Size) “outside diameter” dimensions. Heat fusion is the preferred method of joining lengths of pipe. Pipe installers should be certified in heat fusion of HDPE pipe. Refer to PPI TR 3 and IGSHPA guidelines for heat fusion joints. Piping above ground may be joined with mechanical fittings made to ASTM D 3035 standards.