SECTION 15026 DETAIL PIPING SPECIFICATION – HIGH-DENSITY POLYETHYLENE DOUBLE-WALL PIPE AND FITTINGS

This spec was part of the Des Plaines, IL River WRF project that bid Feb 26, 2015.

SECTION 15026

DETAIL PIPING SPECIFICATION –
          HIGH-DENSITY POLYETHYLENE DOUBLE-WALL PIPE AND FITTINGS


PART 1 GENERAL

1.1 SECTION INCLUDES

A. High-density polyethylene (HDPE) double-wall pipe and fittings.

1.2 RELATED SECTION

A. Section 15000 - Plant Piping - General: See referenced Section for additional requirements.

1.3 SUBMITTALS

A. As specified in Section 15000.


PART 2 PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS

A. Asahi/America Poly-Flo Dual Containment Pipe

B. Or Approved Equal

2.2 PIPE

A. HDPE shall meet the requirements of ASTM D3350 cell classification 345434C or 355434C. All related accessories shall be made from the same resin.

B. One-piece double-containment pipe shall be used. The primary pipe shall be integral with the secondary pipe via connecting ribs that are continuous down the entire length of each section of pipe. No centralizing clips, spiders, disks or supports shall be allowed.

C. Identical wall thicknesses for the inner and outer walls are required for each size.

D. All systems shall be fitted with at least one molded outer wall adapter with integral burst disk.

2.3 JOINTS

A. Butt-welded per ASTM D2657 and manufacturers recommendations.

B. Flanges where shown on the Drawings.

2.4 FITTINGS

A. Same material as pipe.

B. Unitary double-walled fittings that are molded shall be used throughout. Permanent alignment of the inner and outer fittings shall be maintained via molded-in ribs. The ends of both the inner and outer fittings shall be flush (in one plane). Molded-in supports shall be set back from the ends of the fittings to allow mixing of any fluids in the annular  space.

2.5 PRESSURE RATINGS

A. Pipe and fittings shall be rated for 75 PSI in all sizes and materials at 73°F.

B. Inner and outer fittings shall both be rated for 75 PSI, including all termination fittings, transition fittings and drainage fittings.


PART 3 EXECUTION

3.1 INSTALLATION

A. All HDPE pipe shall be cut, made up, and installed in accordance with the pipe manufacturer's recommendations.

B. Pipe shall be laid by snaking the pipe from one side of the trench to the other. Offset shall be as recommended by the manufacturer for the maximum temperature variation between installation and the process.

3.2 CUTTING PIPE

A. Cut pipe with milling type cutter, rolling pipe cutter, or abrasive saw cutter. Do not flame cut.

3.3 DRESSING CUT ENDS

A. Dress cut ends of pipe in accordance with the type of joint to be made.

3.4 FABRICATION OF FLANGED PIPE

A. Flanged pipe shall be fabricated in the shop, not in the field, and delivered to the jobsite with flanges in place and properly faced. Threaded flanges shall be individually fitted and machine tightened on matching threaded pipe by the manufacturer.

B. Flanges shall be faced after fabrication in accordance with ANSI A21.15/AWWA C115. Flange-to-pipe threaded joints shall be hydrostatically shop tested to ensure joint integrity.

3.5 JOINING PIPE

A. Flanged: Before connecting flanged pipe, the faces of the flanges shall be thoroughly cleaned of all oil, grease, and foreign material. The rubber gaskets shall be checked for proper fit and thoroughly cleaned. Care shall be taken to assure proper seating of the flange gasket. Bolts shall be tightened so that the pressure on the gasket is uniform. Torque-limiting wrenches shall be used to ensure uniform bearing insofar as possible. If joints leak when the hydrostatic test is applied, the gaskets shall be removed and reset and bolts tightened.

B. Field Welding: Butt welded in accordance with manufacturer's recommendations.

3.6 TESTING

A. All lines shall be tested as listed in the Pipe Schedule shown on the Drawings. Test procedures shall be as specified in Section 15000.

3.7 SUPPORTS AND HANGERS

A. As specified in Section 15000.


END OF SECTION