FAQ & INFORMATION

Polypropylene Random Copolymer (PP-R) and Polypropylene Random Crystalline Temperature (PP-RCT)

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With more than thirty years of proven performance, Polypropylene Random Copolymer (PP-R) pipe and fittings have been used throughout the world in plumbing, mechanical and industrial applications. Pipes made from PP-R are lightweight, do not corrode, rust, or scale and they are joined via heat fusion for permanent, leak-free joints. These pipes may be used inside the building, outside the building with U.V. (ultra violet) Protection or Direct buried. (See section on UV Protection)
 

Applications include but are not limited to the following systems:
 

Hot and Cold Potable Water
Food Processing
Hydronics
Geothermal
Industrial
Compressed air and vacuum
Rainwater Collection,
Gray and Reclaimed Water

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Based on the success of PP-R, the next generation of Polypropylene-Random Copolymer was developed with a special crystalline structure that exhibits an improved pressure rating at elevated temperatures. It is called Polypropylene-Random Crystalline Temperature (PP-RCT). Its enhanced crystalline structure is created through a special nucleation process that enables the pipe to operate at higher pressures at elevated temperatures. This advanced resin is used in PESTAN’s Mechanical and Potable Water Pipes and Fittings.
 

In long-term pressure tests, the outstanding performance characteristics of PP-RCT vs. standard PP-R is apparent:
 

PP-RCT : 50 year strength at 70˚C (158˚F) = 5.00 MPa (725 psi)
PP-R : 50 year strength at 70˚C (158˚F) = 3.21 MPa (464 psi)
 

Offering more than 50% improved long-term strength, PP-RCT enables designers to achieve higher pressure ratings than with traditional PP-R pipes of the same wall thickness, or they can utilize PP-RCT’s higher pressure rating and down-gauge to a thinner wall pipe offering higher hydraulic capacities and cost savings.

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Material Stability

Integrity of the PP-R(CT) raw material is not affected during processing and fabrication. More importantly, the material is engineered to withstand long-term service life even at high temperatures.

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Premium Quality

PESTAN’s strict policy on quality control requires the use of premium PP-R(CT) resins produced by the world’s premier resin manufacturers. Material formulations and processing parameters are continuously monitored for compliance and consistency, insuring a 50+ year service life when used in PESTAN approved applications.

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UV Protection - Indoor vs. Outdoor

PP-R(CT) pipe and fittings are not stabilized for direct Ultraviolet (UV) exposure. Over time, UV exposure causes degradation, resulting in decreases in the pipe’s physical properties and chemical resistance as well as affecting the long-term performance. If the pipes are going to be used outdoors, they should be encased in a protective wrap or insulation.

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Hydrolysis

PESTAN PP-R(CT) pipes are completely resistant to hydrolysis meaning they will not react with water. The pipe will not break down and no chemicals will leach into the water throughout its lifecycle. Additionally, these pipes do not impart any taste or odor into the fluids they convey. This makes them ideal for the transport of water and food grade
liquids.

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Corrosion Resistance

Unlike metal piping systems that have to be upsized due to corrosion, PP-R(CT) systems do not corrode, rust or scale. No corrosion means long-term consistent flow, no decrease in pipe inside diameter, lower pumping costs and a better quality of water.

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Chemical Resistance and Special Applications

PP-R(CT) is safe for the transport of drinking water and any food-grade fluids. Because of the non-polar characteristics of polypropylene and a specially designed additive package, PP-R(CT) systems are also suitable for the distribution of most chemicals*. Although PP-R(CT) is resistant to a wide variety of chemicals, it is very important to select appropriate "transition" fittings (fittings with metal inserts). 

Warning: Pestan does not recommend PP-R(CT) being used in installations where copper and highly aggressive water are present. The water attacks the copper and releases free ions that negatively affect water and any material it contacts in the system. Even inert materials such as polypropylene can be affected. To avoid the erosion/corrosion of the copper piping systems, please follow recommended design instructions from The Copper Tube Handbook, by Copper Development Association (page 11).
 

Note: According to the ANSI/ASME B31.3 Process Piping Code, thermoplastic piping should not be used in flammable fluid service above ground, in nominal sizes above 1 inch (32 mm). With sizes 1 inch and below, secondary containment should be provided.

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Fiber Composite Pipes Integrated Expansion and Contraction Control

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Temperature changes cause thermoplastic pipes to expand and contract in the linear direction. With PESTAN’s PP-R(CT) Fiber Composite pipes, expansion and contraction is controlled in the linear direction. This is achieved by the addition of a fiber layer coextruded into the mid-wall of the pipe. The middle layer is comprised of oriented fibers encapsulated in

PP-RCT, which does not expand when exposed to temperature changes. Therefore, overall expansion of the pipe is minimized. Not only does it reduce the need for additional expansion control, it also provides rigidity and stability.
 

PESTAN’s Mechanical and Hot Drinking Water Pipes are with the Fiber Composite layer and are joined via heat fusion and use standard PESTAN PP-RCT fittings.
 

Heat Fusion Connections

PESTAN piping systems use the Heat Fusion process to create the homogeneous connections between the pipe and the fittings. The connections use no added solders, solvents, glues or similar products. When heat fusing PP-R(CT) components, extra material is collected at the joint which makes fusion joints the strongest points of the system. Properties of the material do not change when heat fused, so connections between pipes and fittings are strong and safe.

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50+ Years of Savings

PESTAN has developed long-lasting, low maintenance piping systems. Our products are produced from proprietary resin formulations insuring long term performance. The pipes are resistant to scaling and corrosion; the walls of the pipes are extremely smooth and therefore have a low friction coefficient eliminating abrasion. Furthermore, mechanical joints, the weakest point of a traditional piping system, are eliminated by using heat fusion as the joining method. With heat fused joints, physical stresses will not damage the integrity of the joints.

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Low Thermal Conductivity

The value of Thermal conductivity of PP-R(CT) material is 1.67 BTU(in/hr. ft² °F). This low conductivity value, combined with the thickness of the pipe and fitting wall, acts as a natural insulator. Traditional metal piping systems have much higher Thermal Conductivity values. Under normal operating conditions, non-insulated PP-R(CT) pipes have less heat loss or gain and greater resistance to condensation as compared with metal and other types of plastic piping systems.

One of the objectives of Energy and Building codes is to improve operating efficiencies. They make recommendations for the required amount of insulation for piping systems. Because PESTAN piping systems have much lower heat losses and heat gains than traditional metal systems, our piping system is capable of operating at an equal or in most cases a more efficient level than other metal systems under the same code. If there is a need for insulation, both space and material can be saved using PP-R(CT) systems. Further details on this are given in Section 5.

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Insulation and Energy Savings

The level of insulation required in a PP-R(CT) Piping system is relative to the thickness of the wall. A chart on the equivalent R values of PESTAN pipe can be found in Chapter 5. A 50% improvement in heat loss or heat gain can be realized when comparing non insulated metal pipe to non insulated PESTAN PP-R(CT) pipe. Before starting installation, always check code
requirements to make sure that your installation complies. Both past and current ICC and ASHRAE energy codes support insulation savings when using PESTAN pipes (see Section 4).

Although PP-R(CT) is a better insulator than metal pipes, care should be taken in areas where there is a high dew point or where the ΔT between the fluid in the pipe and the ambient temperature is great. The pipe has the potential to condensate. In these situations, insulation is recommended.

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Fittings Insulation Advantage

The socket fusion fittings vary from ½" to 4" (20 mm – 125 mm). When pipes are inserted into the socket of the fitting, thickness of the PP-R(CT) material is increased at the joint. When thickness of the overengineered fittings and pipe are added in conjunction with natural thermal resistance of the material, need for fitting insulation may be eliminated in certain applications.

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Natural Sound Insulation

Because of the integrated natural sound insulation, pressure billow and water flow noise are lessened by PP-R(CT) pipes, enhancing the quality of living for the occupants of the buildings.

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Prevention of Biological Growth

Light transmission through PP-R(CT) pipe is less than 0.2%. Therefore, algae and other biofilm attachment is not supported. This benefit makes it an ideal piping system for health care facilitates and food grade applications.

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Flame and Smoke

PP-R(CT) pipes will burn, but are not classified as flammable. The NFPA classifies these products as a 1 (slow burning) on a scale of 0 to 4 with 4 being the quickest to burn. When burning, these pipes emit C02 and H2O vapor. In an underdeveloped combustion situation, small amounts of CO can be emitted, just as it is from wood or wood-based products. PP-R(CT) pipes require special wrapping when installed in plenums or other spaces where the Code requires the pipe to meet a Flame Spread Index (FSI) of 25 and a Smoke Development Index (SDI) of 50. You may use ASTM E84 OR CAN/ULC S-102.2
approved materials to comply with the code. Always be sure to review project and local code requirements before beginning an installation. For more information visit Pestan's web site at http://www.pestanpipes.com/flame-and-smokerating/

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Safe Handling and Installations

Installation of PP-R(CT) piping system is preferred over other piping systems because they weigh less and are joined using heat fusion, instead of solders or glues (eliminating VOC’s during the process). Installers should follow all safety recommendations established by PESTAN as well as all project, local, state and federal (OSHA) safety guidelines when working with PESTAN PP-R(CT) piping systems.

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