BS EN 1254-8:2021 pdf free download – Copper and copper alloys一Plumbing fittings Part 8: Press fttings for use with plastics and multilayer pipes.
4.2.3.5 Press fitting with elastomeric seals for fuel gas application inside buildings
The main aspect for the durability of tightness for fuel gas application inside buildings is the ozone behaviour of the elastomer. Therefore the elastomer shall be ozone resistant and comply with the requirements of ENS49 class B2 or higher.
4.2.3.6 Press fitting with elastomeric seals for fuel gas application outside buildings
The main aspect for the durability of tightness for fuel gas application outside buildings depends on the elastomeric sealing element. Therefore, the elastomer shall comply with the requirements of EN 682 types GAL or GBL.
4.3 Resistance to high temperature for fittings with elastomeric seals (for heating networks)
The main aspect for the resistance to high temperature liquid applications depends on the elastomeric sealing element. Therefore the elastomer shall have the appropriate characteristics as specified in EN 681-1. The elastomeric sealing elements shall conform to the requirements of EN 681-1:1996. Table 3 for continuous hot water supply up to 110 °C except for Isoprene-Isobutylene Copolymer (lIR) where a volume change in water up to and including 15 % is permitted.
4.4 Release of dangerous substances
National regulations on dangerous substances may require verification and declaration on release, and sometimes content, when construction products covered by this document are placed on those markets. In the absence of European harmonized test methods, verification and declaration on release/content should be done taking into account national provisions in the place of use.
NOTE An informative database covering European and national provisions on dangerous substances is available at the Construction website on EUROPA accessed through: http://cc.europa.eu/growth/ tooLs-databases/cp-ds.
4.5 Durability
4.5.1 Durability of internal pressure: Resistance to stress corrosion
Fittings manufactured from copper and copper-tin-zinc alloys (CuSnZnPb) shall be considered to be resistant to stress corrosion according to EN 12502-2 and copper-zinc-silicon alloys containing  2 % Si are also considered to be resistant.
Fittings manufactured from CuZn-alloys shall be considered to be resistant to stress corrosion when the product has a hardness HHW10 2,5/62.5  110 measured according to EN ISO 6506-1 or a hardness HV5  134 measured according to EN ISO 6507-1.
Fittings manufactured from copper alloys with a zinc content of 10 % or greater not mentioned above shall be tested and assessed according to 5.4.1, and shall show no evidence of cracking.
4.5.2 Durability of tightness
4.5.2.1 ResIstance to dezincificatlon
This requirement only applies where a fitting is declared to be resistant to dezincification.
The resistance to dezincification of alloy fittings can be obtained by the correct material selection and processing of that material.
Alloys containing 15 % or less zinc provide a good resistance to dezincification and don’t need to be tested.
Representative material samples, prior to machining, shall be tested. When tested according to 5.4.2.1. the mean and maximum depth of dezinciuication in any direction shall be expressed in urn and shall meet the acceptance criteria listed below for resistance to dezincification:
— for grade A: maximum 200 lIm;
— for grade B: mean not to exceed 200 um and maximum not to exceed 400 Ilm.
If any of the test pieces do not meet the criteria for the chosen grade, a second lot of test samples from the same batch shall be selected and the test repeated. If any of the second lot of test pieces fail, then the batch represented shall be deemed not to conform to the requirements of this document.