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Plastic Pressure Pipe Systems are used for the conveyance of drinking water, waste water, chemicals, heating and cooling fluids, foodstuffs, ultra-pure liquids, slurries, gases, compressed air and vacuum system applications, both for above and below ground applications. Plastic Pressure Pipe Systems have been in use since the 1950s.

Types of pipes

The most common pipe systems are:

• ABS Pipe Systems
• PVC Pipe Systems (also denoted uPVC, PVCu, or PVC-U Pipe Systems) (produced to EN 1452-1 to 5 :2000 standards for the European market)
• PVC-C Pipe Systems
• PP Pipe Systems
• PE Pipe Systems (both PE80/MDPE Pipe Systems and PE100 (High Density polyethylene or HDPE)
• PB Pipe Systems (Polybutylene)

The type of pipe in use is dependent on the material passed through the pipe, the operating pressure, and the operating temperature

Material characteristics

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ABS (Acrylonitrile Butadiene Styrene)

See also main article Acrylonitrile butadiene styrene ABS is suitable for the conveyance of potable water, slurries and chemicals. ABS complies with the toxicological requirements of the British Plastics Federation and the British Industrial Biological Research Association (BIBRA) code of practice for food usage. ABS Pipe Systems are very suitable for chilled water applications, due to its low temperature properties. ABS is also suitable for use in compressed airline systems.

PVC-U (Polyvinyl Chloride, Unplasticized)

PVC-U or uPVC has excellent chemical resistance across its operating temperature range, with a broad band of operating pressures. Due to its long term strength characteristics, high stiffness and cost effectiveness, PVC-U systems account for a large proportion of plastic piping installations. PVC-U is resistant to most solutions of acids, alkalis, salts and organic compounds miscible with water. It is not resistant to solvents, aromatics and some chlorinated hydrocarbons. PVC-U is not at all suitable for compressed air systems.

PVC-C (Polyvinyl Chloride, Post Chlorinated)

PVC-C has excellent chemical resistance across its operating temperature range, with a broad band of operating pressures. Due to its long-term strength characteristics, high stiffness and cost effectiveness, PVC-C systems are suitable for a wide diversity of plastic piping installations. PVC-C is resistant to many acids, bases, salts, paraffinic hydrocarbons, halogens and alcohols. It is not resistant to solvents, aromatics and some chlorinated hydrocarbons.

PP (Polypropylene)

Polypropylene is suitable for use with foodstuffs, potable and ultra pure waters, as well as within the pharmaceutical and chemical industries. Polypropylene is adversely affected by UV radiation and requires insulation or a protective coating if installed outside.

PE (Polyethylene)

When compared to other plastics, polyethylene shows excellent diffusion resistance, and because of this property, polyethylene has been successfully used for the safe conveyance of gases for many years. Polyethylene has good resistance to acids and caustic substances. Resistant to organic and inorganic solvents at a wide range of temperatures. It is not resistant to strong oxidising acids.

PVDF (Polyvinylidene Fluoride)

PVDF has excellent chemical resistance which means that it is widely used in the chemical industry as a piping system for aggressive liquids. PVDF is a homopolymer without additives such as stabilizers and processing agents. It also displays excellent flame retardant properties. PVDF is listed with many worldwide agencies as suitable for use with foodstuffs, dairy products, in semi-conductor and pharmaceutical manufacturing, and for other applications in the food and drug sector. PVDF is resistant to most acids, alkalis, salts, halogens, alcohols and chlorinated hydro-carbons. Strong polarized solvents, such as ketones and esters, can cause the material to swell.

Components of Plastic Pressure Pipe Systems

There are four key components that make up a plastic pressure pipe system:

• Pipes
• Fittings
• Valves
• Accessories

The range of pipe diameters for each pipe system does vary. However, the size ranges from 12mm to 400mm and 3/8" to 16".

Pipes

Pipes are extruded and are generally available in:

• 3m straight lengths
• 5m straight lengths
• 6m straight lengths
• 25m, 50m,100m, and 200m coils are used for LDPE and MDPE up to 90mm in diameter, and 6m straight lengths beyond.

Pipe fittings

Pipe fittings are molded and the finished product is available as:

• Tee 90° equal
• Tee 90° reducing
• Tee 45°
• Cross equal
• Elbow 90°
• Elbow 45°
• Short Radius Bend 90°
• Socket/coupler
• Socket/coupler reducing
• Union
• End Caps
• Reducing Bush
• Stub Flange
• Full Face Flange
• Blanking Flange
• Composite Union (Brass BSP Thread one side, plain plastic socket the other)

Valves

Valves are molded and the finished product is available as:

• Ball Valve
• Multi Port Ball Valve
• Butterfly valve
• Spring Check Non Return Valve
• Ball Check Non Return Valve
• Swing Check Non Return Valve
• Diaphragm valve
• Knife Gate Valve
• Globe Valves
• Pressure Relief Valves
• Pressure Reducing Valves

References

• Pipestock Limited. Installing Plastic Pressure Pipe Systems. Pipestock.

• Mike Greig. Plastic Piping Systems, Guide to Design and Installation. Effast Pipe Systems. ISBN 1904133339.

• Dr Tarik Al-shemmeri BSc MSc PhD CEng MIMechE of Staffordshire University. The Red Book, A Guide to the Design and Installation of Plastic Pipeline Systems. ISBN 1897898819.

• Articles lacking sources from July 2007
• Piping
• Plumbing
• Valves