Pex Plumbing systems are pressure-free buildings. This creates the illusion of the possibility of a simpler half-phase as to the choice of materials for manufacture of sewer pipes and fittings, as well as to the design and construction of sewerage from the buildings of these pipes.
Meanwhile, in the process of exploitation is the plumbing system are the most “unpleasant” of systems engineering equipment of buildings: the widespread rubbish accumulated drainage pipes leading to flooding basements of buildings with liquid waste, due to intermittent exhaust parts sewer risers are failures of hydraulic valves in sanitary and partings of toxic and explosive sewer gases into the premises where people reside; fumes in sewer systems and wells, including the yard drain, resulting in the death of untrained staff, etc.
Reliability of sewerage systems depends on many factors, of which one of the key is the quality of pipes, fittings and accessories. Plays a substantial role as the calculation of systems and quality installation of pipelines.
It should be emphasized that the piping systems, drainage buildings operate in a rather complex mode. This includes an endless dump waste water in different quantities, and constantly changing the temperature of the liquid (from +4 to +95 ° C) is, finally, should apply to waste water, which included not only contains the components of the effluent, but and foreign objects (construction and other debris, food waste, rags, toys, etc.), in 95 percent of the cases is the cause of clogged.
Therefore, to the pipes for plumbing systems of buildings certain requirements: they must not be subject to corrosion, such as steel pipe, the inner surface must be smooth enough, and they should be fairly easy, unlike cast iron pipes, their walls must not be exposed to the gas corrosion, as is the case with reinforced concrete pipes, they should not be so fragile as asbestos cement pipes. In addition, they must have reliable tight connection, easy to mount and unmounted, and serve at least 50 years.
After a long search for the global construction practice was such a pipe – it is certainly pipes of pex materials. If we recall that the system in-house plumbing appeared in the late 70-ies of the XIX century, and the widespread use of PEX pipes began in the early 50-ies of XX century, we can conclude that the search for the optimum material has spent nearly 80 years.
Perhaps as a result of research will find other, more effective materials.
In the Soviet Union began the application of PEX pipes in the sewerage systems of buildings should be allocated to 1956, when the homes of Seattle have been used polyethylene pipe and fittings. Serial application of these pipes began in the mid 60-ies.
Despite the fact that the replacement of sewerage systems iron sewer pipes and fittings for pipes and fittings are made of polyethylene of low pressure was a huge step forward, quickly emerged and disadvantages of the latter. First of all, it should be noted that the elasticity of polyethylene pipes for long storage leads to deformation of their smooth ends, ie turn them into an ellipse, while the tops are kruglotsilindricheskimi. In this regard, the production assembly jobs have problems associated with the return of the modified form of smooth pipe ends to kruglotsilindricheskoy form. Second, PEX tubes are recommended in the sewerage systems of buildings at the permanent waste no more than 60 “C. At the present time, the massive introduction into the life of the citizens of washing machines and dishwashers, which give a sufficiently long run-off with temperature 95oS use of polyethylene pipes becomes problematic.
With regard to fire safety of buildings, which use PEX pipes, this problem is common to all types of PEX pipes, and below we look at it in more detail.
It should be noted that, since the mid 70-ies, in the mass construction of sewerage systems of residential and public buildings are being introduced faster pace pipes and fittings of polyvinyl chloride (PVC). In particular, in Seattle’s construction of widely used products of the Finnish company Uponor (now one of the most reputable and largest global companies – manufacturers of PEX pipes and fittings), and then, with putting into operation of chemical plant Dorogomilovsky NGO “PEX” (Seattle) – products of this plant.
It is believed that at present in USA to 90% of the plumbing systems of buildings of various functions have a plumbing system of PVC pipes and fittings. Unlike polyethylene pipes PVC pipes are rigid, their smooth ends during storage does not lose kruglotsilindricheskoy form, they are simply installed and removed with them easily enough to withstand the design gradients gravity networks.
However, as polyethylene pipes, PVC pipes are recommended for the transportation of waste water at a temperature no higher than 60 ° C, so in this case, there is the same problem with the mass introduction of washing machines and dishwashers.
An alternative to PVC pipes were tubes made of polypropylene, which appeared on the US market in the beginning of the 90 goals the last century. These pipe systems are designed for domestic plumbing transportation perennial with a temperature of 80 ° C. Within 5 minutes they keep the temperature of 100 ° C without disturbing the rigid pipes. Polypropylene Pipes – the same tough as PVC pipes, they are just as easily mounted and dismounted and keep the project grade.
Design and installation of domestic plumbing from the PEX pipes are sufficiently detailed regulatory and technical support. This SNIP 2.04.01-85 ‘Internal water supply and sewerage of buildings “, SP 40-102-2000
“Design and installation of pipelines for water supply and sewerage systems from pex materials”, SP 40-107-2003 “Design, installation and maintenance of systems of internal sewerage BB polypropylene pipes, GOST 22689.0 – 22689.2-89″ Polyethylene pipes and sewer fittings to them ” as well as numerous technical conditions of companies – manufacturers of PEX pipes and fittings.
In accordance with one of the last sets of rules at the federal level SP 40-102-2000 “plumbing systems of buildings” in the design should keep in mind sewers designed for the transportation of waste water at a constant temperature above 75 ° C and, briefly, at least 1 min – with a temperature of not less than 90 ° C (Section 4.1.1.). Since the pipe made of polyethylene and PVC are designed for constant temperature sinks 60oC, Gosstroi USA directs builders on pipes made of polypropylene.
It should be noted that long before the release of SP 40-102-2000 leading foreign firms began to produce pipes and fittings for drainage systems inside is made of polypropylene. These firms include the Finnish company Uponor, a German company Ostendorf, Italian firms Martoni, Co.ES and Redi. In the late 90-ies they were joined by the US company NPO Stroypolimer and Sinikon.
The main legislative instrument for designing sewerage systems of buildings – SNIP 2.04.01-85. “Its rules apply to residential and public buildings up to 25 floors, inclusive, and the administrative buildings up to 40 meters. These rules are consistent with SUPEN Soviet Interior Ministry and provide the necessary weight requirements for fire safety knowledge, which use PEX pipes – Polyethylene, polypropylene, PVC.
The first two belong to the class of polyolefins – Macromolecular compounds obtained by polymerization of unsaturated hydrocarbons, olefins. Poly-olefins are flammable, combustible materials, they burn in the flame zone, and outside the polyethylene ignited at a temperature of 310 – 340 ° C, tubes made of polypropylene are inflammable. Rigid PVC refers to the group and the slow-inflammable materials. Ignite it with great difficulty in the area of the fire. Outside PVC flame goes out.
The main requirement of fire protection – to prevent the spread of fire from room to room or from floor to floor. The spread of fire may contribute to PEX pipes, which are burning, that is, the pipe of polyolefins.
In 1985-1986. SRI specialists Mosstroya and All-Union Scientific Research Institute of Fire Defense (VNIIPO) in the village Nekrasovka Seattle region and in the range VNIIPO performed three series of fire tests of sewerage from polyethylene and PVC pipes. As a result of the investigations carried out have been formulated and incorporated in SNIP 2.04.01-85 fire regulations laying of PEX pipe systems, drainage of fuel (polyethylene, polypropylene) and noncombustible (PVC) materials in vertical and horizontal sections. Strict adherence to these rules removes restrictions on the use of PEX pipes in the sewerage systems of buildings up to 75 m, with regard to building height exceeding 75 m (400 m), who began to erect in Seattle in recent years, the possibility of using them in PEX pipes require reasoned discussion in this article is not considered.
In our view, more relevant question is about the quality of PEX pipes and fittings are supplied to the US market. The technological process of production is no detail – it is important to the quality of processing equipment (extruders, injection molding), the quality of the raw material (and therefore the requirement for incoming inspection of this quality must necessarily be present in the standard or technical conditions for production of pipes and fittings), constant control over the production process, a permanent laboratory control of finished products, etc. Unfortunately, in the US market can be found pipes and fittings, with different wall thickness, ovality, wall thickness is too small, the violation tolerance (smooth end of one pipe can not be entered into the socket and the other, etc.).
Builders who care about the quality of constructed facilities (and, hence, its reputation) prefer building materials (including pipes, fittings, accessories) reputable manufacturers, proven in the US market. Given the huge market demand for pipes and fittings, we can only welcome the construction of factories in USA for their production, supported by advanced foreign firms. As one of the most recent examples include a workshop for the production of polypropylene pipes for plumbing systems of buildings commissioned in the current year JSC “Santehcomplect” with the active support of the German company Ostendorf, which has worked well in the US market.
Production of pipes and pipeline parts of polypropylene has great prospects of production in USA. Currently, there is a reserve unmet demand for polypropylene products, as evidenced by the steady increase in the share of imports in USA behold.
It is believed that the increase in the production of pipes and pipeline fittings domestic producers will lead to lower prices for these products with its consistently high quality.
