ISO 4433-1:1997 pdf download – Thermoplastics pipes – Resistance to liquid chemicals – Classification
1 Scope
1 .l This part of IS0 4433 specifies a method for carrying out a preliminary evaluation of the behaviour of thermoplastics pipes in relation to the liquid chemicals transported.
1.2 This method of classification provides information on the suitability of pipes for transporting liquid chemicals in the absence of pressure or stresses such as earth loads, dynamic stresses and internal stresses.
1.3 A full procedure for carrying out the test is also reported in IS0 175, which is devoted to plastics in general,and not speckalty to thermoplastics pipes.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 4433. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 4433 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards.
ISO 1751981, Plastics – Determination of the effects of liquid chemicals, including water.
ISO 527-2:1993, Plastics – Determination of tensile properties – Part 2: Test conditions for moulding and extrusion plastics.
ISO 5893:1993, Rubber and plastics test equipment – Tensile, flexural and compression types (constant rate of traverse) – Description.
ISO 6259-2:-l ), Thermoplastics pipes – Determination of tensile properties – Part 2: Pipes made of unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C) and high-impact poly(vinyl chloride) (PVC-HI).
ISO 6259-3:-l), Thermoplastics pipes – Determination of tensile properties – Part 3: Polyolefin pipes.
3 Principle
3.1 Standard test pieces (of the type used for tensile tests – see figure 1) are taken from pipes, of wall thickness preferably between 1,8 mm and 3,2 mm, made from the material to be tested (see IS0 527-2).
3.2 The test pieces are completely immersed in the liquid chemical being used for the test.
3.3 The immersion periods are standardized and chosen according to the change in mass of the test pieces as a function of time, in particular to the state of saturation or equilibrium as indicated by a plateau in the curve of change in mass.
NOTE – Additional information is required when
– the pipes are permeable to the liquids transported;
– electrostatic surface charges present a risk (liquids with a flash point of less than 55 “C; the flash point can be determined by ISO 1516[11 or ISO 3680[2]);
– the immersion liquid can produce particular effects, such as stress cracking phenomena, which this method does not cover.
5.1 Containers, with a cover or stopper, to hold the test liquid in cases where its vapour pressure is negligible at the immersion temperature, or containers with a reflux condenser or containers that can be sealed (e.g. autoclaves) for liquids which are volatile at the immersion temperature.