ISO 4633:2015 pdf download – Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for materials.
4 Requirements 4.1 Requirements for materials 4.1.1 General The materials shall be free of any substances which can have a deleterious effect on the fluid being conveyed, the life of the sealing ring, the pipe, or the fitting. Elastomeric components of composite seals not exposed to the contents of the pipeline are not required to meet the requirements of 4.1.2. 4.1.2 Effect on water quality For cold-water applications, the materials shall not impair the quality of the water under the conditions of use. The materials shall comply with the national requirements in the country of use. 4.1.3 Microbiological deterioration The materials shall be resistant to microbiological deterioration if the application so requires. The test methods and the requirements shall be as specified in national standards.
4.2 Requirements for finished seals 4.2.1 Dimensional tolerances Tolerances shall be specified from the appropriate classes in ISO 3302-1. 4.2.2 Imperfections and defects The seals shall be free of defects or irregularities which could affect their function. Classification of imperfections shall be in accordance with ISO 9691, as follows: — surface imperfections in zones involved in the sealing function, as described in ISO 9691:1992, 4.1.1, shall be considered as defects; — surface imperfections in zones not involved in the sealing function, as described in ISO 9691:1992, 4.1.2.1 b), shall not be considered as defects. Major surface imperfections in zones not involved in the sealing function, as described in ISO 9691:1992, 4.1.2.1 a), could be considered as defects. This shall be agreed upon between the interested parties, the acceptance criteria depend upon the seal type or design. Internal imperfections as described in ISO 9691:1992, 4.2 could be considered as defects. The compressive force referred to in ISO 9691:1992 can be determined in accordance with ISO 7743. The acceptable limiting values of the compressive force shall be agreed upon between the interested parties. These values depend upon the seal type or design. 4.2.3 Hardness When determined by the micro-test method specified in ISO 48, the hardness shall comply with the requirements given in Table 2. If the dimensions of a seal are appropriate, the normal test method specified in ISO 48 may be used provided that the micro-test method is used for reference purposes. For the same seal, or along the greatest length of an extruded profile cut to make the seal, the difference between the minimum and maximum hardness shall not be more than 5 IRHD. Each value shall be within the specified tolerances. 4.2.4 Tensile strength and elongation at break The tensile strength and elongation at break shall be determined by the method specified in ISO 37. Dumb-bell-shaped test pieces of type 1, 2, 3, or 4 shall be used.