Defects found in brass pipe fittings
Tests conducted by the Finnish Safety and Chemicals Agency (Tukes) found defects in brass fittings which may be installed in domestic water pipes. The brass alloys of two fittings were unsuitable for conditions in Finland and were withdrawn from the market. The testing of brass fittings and manifolds comprises part of a comprehensive construction product testing programme to be implemented this year.
Seven straight brass compression fittings and four manifolds which are suitable for both for plastic PEX pipe systems and copper were chosen to the tests. The products were purchased from consumer product stores and wholesale suppliers for professionals and they originated from different manufacturers in Finland and Europe and from outside Europe.
The tests ascertained whether the products in question met the standards applicable to them. In Finland, there are national standards for fittings on account of the fact that the composition of water in Finland differs from that in other European countries.
According to Finland’s building regulations, materials coming into contact with water in a water supply installation must not cause a health hazard. Water supply installations must also be durable and reliable throughout the design lifetime. Likewise, fittings which may be installed in domestic water pipes have technical standards relating to user health and to the functionality of the whole pipe system. The brass alloy of fittings should be dezincification resistant and must not leach substances that are hazardous to health. Dezincification refers to phenomenon corrosion where zinc is leached into water from a brass alloy, leaving a porous, copper-containing structure.
There is also a voluntary type approval system for fittings enabling the manufacturer to demonstrate that the fitting is suitable for use in Finland.
Deficiencies in the dezincification resistance of two fittings
The fittings and manifolds were inspected for leaching of heavy metals (lead and cadmium) hazardous to health, and for stress corrosion cracking and dezincification resistance. Deficiencies were detected in the dezincification resistance of two fittings. Neither lead nor cadmium in excess of the permitted amount leached from the tested fittings.
The tests detected deficiencies in the Comisa brand fittings imported by Bauhaus and in the straight 15-mm compression fittings imported by Evimex Oy and manufactured by IDC Fluid Control. Bauhaus has withdrawn the fitting in question. These fittings should not be used in domestic water systems but they are suitable for other uses, such as heating and gas systems. According to Evimex Oy, fittings made of an ordinary brass alloy were mixed with special brass fittings on the production line. According to the factory the numbers of imported fittings were low, and in the future quality control will be enhanced. The dezincification resistant fittings of the manufacturer in question can be identified by the CR symbol on the fitting’s body.
Senior Officer Paula Porkola, tel. +358 29 5052 081 and Head of Unit Kurt Kokko, tel. +358 29 5052 128, [email protected]
The testing of the fittings is part of a comprehensive construction product testing programme that started at the end of 2016 and will finish at the end of 2017. Building products from various sectors are being comprehensively tested in the programme. The aim is to obtain a picture of the general quality of building products and their conformity with standards. The results will also enable improvement in the monitoring of building products so that it is as efficient and effective as possible.
What does dezincification mean?
The quality of Finnish drinking water differs from the quality of water in a number of other countries. Finnish water corrodes metals more easily than, for example, in central Europe and for this reason the brass quality generally used and approved in other countries is not necessarily suitable for conditions in Finland. The quality of the water affects corrosion of metal parts and leaching of metals. Dezincification is brass corrosion, in which brass leaches zinc into domestic water, leaving a porous, copper structure. It can weaken a fitting causing seepage or even cracking. Corrosive sediments inside a fitting can cause pipe blockages. According to studies, dezincification may cause leaks already after a few years have elapsed since a fitting was taken into use.
Dezincification resistant brass can be identified by the letters CR or DZR. In addition, the national type approval symbol, STF, on a brass fitting or its packaging means that the brass alloy should be dezincification resistant. The abovementioned symbols are not necessarily marked on the smallest fittings, even if the alloy is dezincification resistant.
What should manufacturers and importers be aware of?
Manufacturers may apply for type approval for compression fittings and manifolds that may be installed in a domestic water system. The Finnish type approval means that the product meets the requirements of the national legislation.
Manufacturers should ensure through their quality control that the properties of a product remain compliant with the type approval.
Applying for type approval is voluntary for manufacturers, but there may be products on the market which meet the national requirements, even though they do not have a type approval symbol. If the manufacturer of a product has not applied for a Finnish type approval, the importer must check by means of testing reports and certificates that the brass fittings are suitable for conditions in Finland.
What should building project operators be aware of?
Operators intending to start a construction project are obliged to ensure that the building products comply with the standards. If the components of a domestic water system do not meet the standards, the system may not necessarily last for the estimated lifespan.
In order to minimise health risks and damage from leakage, the purchaser should ensure when choosing the equipment for a water system that the product is suitable in terms of its properties for conditions in Finland and the location in question.
Operators intending to start a construction project must require that brass components to be fitted in a water system are dezincification resistant. The designer should indicate in the plans that the brass components are dezincification resistant and the contractor should choose products that meet the standards.
Before taking a water installation into use, a proof test with water and a thorough flushing should be performed.
During use, property owners should carry out or have carried out a visual inspection of the pipe and its equipment on an annual basis. Dezincification of brass components can be identified from the white sediment or reddish colour on the outside of the fitting.
More information on the CE marking of building products, type approval and building location-specific approval pursuant to the Decree on Type Approval as well as on standards relating to products is available in Finnish at rakennustuoteinfo.fi.