PP pipes and fittings for internal sewers

The PP internal sewage systems were among the first modern plastic systems that have entered on the Romanian market after 1990. The new system with PP pipes and fittings with socket and gasket brought a major change especially due to simple installation but also due to the physicochemical properties of the polypropylene. 

Polypropylene is a thermoplastic synthetic resin with a lower density than polyethylene but, with a higher mechanical strength, a higher melting point and a better dimensional stability. It is a colourless and translucent thermoplastic product with good mechanical, dielectric and electrical insulation properties as well as with a high resistance to chemical agents.    

The PP pipes and fittings system with socket and gasket is used especially for internal sewage and ventilation systems. The high resistance to corrosion and to chemical agents recommends this system not only for residential use but also for industrial use in the chemistry or pharmaceutical industry.

The maximum temperature of the wastewater transported through the PP pipe systems is up to 95°C for short periods of time.

PP pipes and fittings are produced through extrusion, namely through the injection of PP granules mixed with dyes, filling materials, stabilizers and friction additions.

See TeraPlast Catalog

You can find the complete range of products in the TeraPlast 2020 catalog.

Features and advantages of the PP pipes and fittings system for internal sewage 


PP pipes and fittings have a high resistance to both high temperatures (60°C run up to 95°C for short periods of time) and low temperatures (up to -15°C).


Both the PP pipes and fittings have a high chemical resistance to most aqueous solutions, to the aggressive action of caustic substances or of aqueous acid solutions. Thus, PP pipes and fittings can be used to transport basic or acid aqueous solutions, mineral salts, etc. that have the pH between 2 and 12. Therefore, PP pipes and fittings are resistant to the detergents in the water from the washing or dishwashing machines.     


The gaskets used for pipes and fittings are made from elastomeric material that guarantees a long-lasting resistance even in harsh conditions.  


Given that water in suspension may contain different types of particles, abrasion resistance needs to be taken into consideration for pipes and fittings. The PP system ensure a high resistance to abrasion even in harsh conditions due to the interior walls that are extremely smooth. 


This is an important feature especially for buildings that are subject to vibrations or that are located in areas with high seismic risk. This feature is due mainly to the socket and gasket joining that also works as an expansion compensator. 


Shock resistance is optimal at normal temperatures. This resistance is valid even at low temperatures.


The low weight of the components that are part of the PP pipes and fittings systems ensures an extremely high manoeuvrability in terms of transport, storage and components handling as well as its installation. Likewise, the gaskets ensure an easy and tight joining of the components, that allows a fast installation. For a fast installation is recommended to lubricate the gasket and the end of the pipe that will be provided with a socket.   

The sealing is done using synthetic rubber gaskets with a long lifetime, which are mounted in the profiled element of the pipe and fittings’ socket. The sealing is ensured even in case of pipe deformation within acceptable limits or in case of its movement. The pipes and the fittings are delivered with gasket.  

The estimated lifetime of the PP pipes and fittings system is of minimum 50 years.

The PP internal sewage system offered by Teraplast is a complete and diversified pipes and fittings system manufactured in accordance with SR-EN 1451-1/2 and SF98/2017. 

In what concerns the size, the range of diameters for the PP pipes and fittings offered by Teraplast varies between 32 and 125 mm for pipes and between 32 and 160 mm for fittings

Components joining

One of the main features of the PP system is the possibility of an extremely fast joining, exclusively by hand, between the components using sealing gaskets. All the components (pipes and fittings) are foreseen with socket and gasket.  

This simple way of joining excludes completely the use of adhesives or the pipe heating to ensure the joining.

Before installation, will be verified the gaskets for all the pipes and fittings as well as any other flaws. In case sand or other solid materials are discovered inside the pipes or the fittings (due to outside storage) and their sediment on the gaskets, these will be removed, cleaned and re-installed to ensure a tight and reliable sealing.   

At installation, the end of the pipe that is not provided with a socket will be introduced in the socket of the pipe that was prior installed. The flow direction is from the end of the pipe that has a socket towards the end of the pipe that is not provided with the socket.

The pipes are foreseen with a chamfer. The pipes that will be delivered to the site will be cut at a 90° angle compared to the horizontal axis and afterwards the cut will be deburred and then with the help of a rasp will be made a new chamfer at 15° angle.    

ATTENTION! It is forbidden to shorten the fittings because they will no longer ensure a proper joining.

After you make sure that the gasket is properly positioned in the socket, lubricate the gasket and the end without socket that will be joint using a special lubricant. Make sure that the two elements that will be joint are properly aligned.

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