This specification is limited to 10.0 bar g. maximum pressure and +50° / – 20C water temperature.
Aboveground & Underground Cooling Water Piping Technical Specification
CORROSION ALLOWANCE: 0
MATERIALS:
Medium and High Density Polyethylene (MDPE & HDPE) pipe and fittings.
All materials shall be as those manufactured by the approved manufacturer Glynwed Pipesystems (Durapipe) or equal.
UNITS OF MEASURE
All dimensions are given in millimeters (mm). Refer to polyethylene pipe to nominal pipe conversion table.
NOTES
- The piping systems shall conform to the provisions of the ASME Code for Process Piping, ASME B31.3, Chapter VII. Nonmetallic piping shall conform to the provisions of Chapter I through VI of this Code unless those provisions are:
- specifically modified in Chapter VII or
- denoted as being applicable only to metals or metallic piping.
- All pipe and fittings shall be clearly marked with the manufacturer’s name or trademark, size, schedule (SDR), material, applicable ASTM/ BS designation, country of manufacture, and the manufacturers certification logo.
- Aboveground piping to be of Black polymer and belowground piping to be of Blue polymer.
- Certification shall be a certificate of conformity for materials to this specification.
- The use of flanges is limited to those situations where portions of the piping system must be disassembled for cleaning purposes, at valves and fire hydrants, and at aboveground transition to ferrous piping systems. When flanges are used with butterfly valves, the clearance requirements of the valve must be checked against the inside diameter of the moulded flange adapters.
- A totally fusion welded system is required. Butt fusion of pipe having unequal wall thicknesses is not allowed.
- Piping system shall be pressure tested hydrostatically with clean water at 150% of design pressure in accordance with Air Products Pressure Testing Standard M27. The strength of a fusion weld develops as it cools. Allow ample time for the weld to cool ( to manufacturers recommendations) prior to the pressure test.
CAUTION: AIR OR COMPRESSED GAS SHALL NOT BE USED AS A MEDIA FOR PRESSURE TESTING OF PLASTIC PIPING SYSTEMS.
| ITEM | DESCRIPTION (SPECIFICATION OR STANDARD) | NOTE |
| PIPE |
| 20 to 63 | Medium Density Polyethylene (MDPE), Type PE80, Grade SDR11. (See Standards Table) | 3,5 |
| 90 to 630 | High Density Polyethylene (HDPE), Type PE100, Grade SDR11 | 3,5 |
| FITTINGS (ELBOWS, REDUCERS & TEES) | ||
| 20 to 630 | Moulded Electrofusion & Long Spigot fittings Grade SDR11, Class C polyethylene compound. | 3,5 |
| 90 to 630 | Fabricated fittings formed by fusion with SDR11 fitting ( use where space is limited) | 3,5 |
| FLANGES | ||
| 25 to 75 | Stub Flange, Moulded fitting , Class 150 to ASME B16.5 | 3,4,5 |
| 90 to 225 | Stub Flange Assembly, Moulded fitting , with Class 150 galvanised steel backing ring to ASME B16.5 | 3,4,5 |
| 250 to 300 | Slim Flange Assembly with Class 150 galvanised steel backing ring to ASME B16.5 and gasket. | 3,4,5 |
| 250 to 630 | Slim Flange Assembly with PN16 galvanised steel backing ring to BS4504 and gasket. | 3,4,5 |
| GASKETS | ||
| 25 to 225 | Flat Ring RF.1/16” (1.5mm) thick, Class 150, SIGMA 511 or equal to ASME B16.21 | 3,4,5 |
| BOLTING – (Aboveground) | ||
| All Sizes | STUD, carbon steel, full thread ( ASTM A307, Grade B) | |
| All Sizes | NUT, heavy hex, carbon steel (ASTM A563, Grade B) | |
| All Sizes | WASHER, plain, Type B, regular, Grade 302, stainless steel (ASME B18.22.1) | |
| BOLTING – (Underground) | ||
| All Sizes | STUD, stainless steel, full thread ( ASTM F593, Group 2 (316SS)) | |
| All Sizes | NUT, heavy hex, stainless steel (ASTM F594, Group 2 (316SS)) | |
| All Sizes | WASHER, plain, Type B, regular, Grade 302, stainless steel (ASME B18.22.1) |
VALVES
All manual valves are specified by the Contractor / Company – Mechanical Systems Engineering Group. See project-specific valve summary for applicable valves as shown on P&ID’s
PIPE SUPPORTS
The following table lists the maximum allowable aboveground support spacing. Spans are based on HDPE (type PE100) pipe/fittings, grade SDR11 at 50 deg. C. Maximum mid span deflection = 6.5mm
| DN | ||||
| 80 | 90mm | max. support spacing | = | 1.11 metres. |
| 100 | 125mm | max. support spacing | = | 1.31 metres |
| 150 | 180mm | max. support spacing | = | 1.57 metres |
| 200 | 250mm | max. support spacing | = | 1.85 metres |
| 250 | 315mm | max. support spacing | = | 2.07 metres |
| 300 | 355mm | max. support spacing | = | 2.20 metres |
| 350 | 400mm | max. support spacing | = | 2.33 metres |
| 400 | 500mm | max. support spacing | = | 2.61 metres |
| 450 | 560mm | max. support spacing | = | 2.76 metres |
POLYETHYLENE PIPE TO NOMINAL BORE PIPE CONVERSIONS
| DN | NPS | ||
| 15 | 20mm | SDR11 PE80 (mean bore 15.0mm) | 1/2 |
| 20 | 25mm | SDR11 PE80 (mean bore 20.1mm) | 3/4 |
| 25 | 32mm | SDR11 PE80 (mean bore 25.8mm) | 1 |
| 40 | 50mm | SDR11 PE80 (mean bore 40.4mm) | 1½ |
| 50 | 63mm | SDR11 PE80 (mean bore 50.9mm) | 2 |
| 80 | 90mm | SDR11 PE100 (mean bore 72.9mm) | 3 |
| 100 | 125mm | SDR11 PE100 (mean bore 101.3mm) | 4 |
| 150 | 180mm | SDR11 PE100 (mean bore 146.0mm) | 6 |
| 200 | 250mm | SDR11 PE100 (mean bore 202.8mm) | 8 |
| 250 | 315mm | SDR11 PE100 (mean bore 255.6mm) | 10 |
| 300 | 355mm | SDR11 PE100 (mean bore 288.1mm) | 12 |
| 350 | 400mm | SDR11 PE100 (mean bore 324.6mm) | 14 |
| 400 | 500mm | SDR11 PE100 (mean bore 405.9mm) | 16 |
| 450 | 560mm | SDR11 PE100 (mean bore 454.6mm) | 18 |
| 500 | 630mm | SDR11 PE100 (mean bore 511.4mm) | 20 |
INSTALLATION
- Installation shall be as specified by the manufacturer’s specific instructions. Specialized joining equipment shall be as recommended by the pipe and fitting manufacturer.
- Installation shall be by personnel certified in the handling and fusing of MDPE and HDPE piping systems.
- Training shall be by the manufacturer or his authorized dealer or distributor.
- Installation / routing of the aboveground and belowground piping shall be in accordance with Design piping isometric drawings.
STANDARDS
Polyethylene product range to comply with the requirements of one or more of the standards listed below.
BS5556 – 1978 General requirements for dimensions & pressure ratings for pipe of theroplastic materials.
BS6572– 1985 Specification for blue polyethylene pipes up to nominal size 63 for below ground use.
BS6730– 1986 Specification for black polyethylene pipes up to nominal size 63 for above ground use.
WIS 4-32-03 – 1987 Specification for blue polyethylene (PE) pressure pipe for underground or protected use.
WIS 4-32-09 – 1991 Specification for black polyethylene (PE) pressure pipe for aboveground use.
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