This part of EN1453 specifies the requirements for structured-wall unplasticized poly(vinyl chloride) (PVC-U) pipes and the system intended to be used for soil and waste discharge applications (low and high temperature) inside buildings (application area code “B??) NOTE1 The intended use is reflected in the marking of products by “ B??. This part of EN1453 is also applicable to structured-wall unplasticized poly(vinyl chloride) (PVC-U) pipes, and the system intended for the following purposes: ventilating part of the pipework in association with discharge applications; rainwater pipework inside building. It also specifies the test parameters for the test methods referred to in this standard. NOTE2 Single layer foamed PVC-U pipes and spirally-formed PVC-U pipes are not covered by this standard. This standard covers a range of nominal sizes and gives recommendations concerning colours. NOTE3 It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national regulations and installation practices or codes. For external above ground application additional requirements depending on the climatic conditions should be agreed between the manufacturer and the user. NOTE4 Pipes conforming to this standard are normally associated with fittings conforming to EN1329‑1 [1]. Pipes, fittings and components conforming to any of the product standards listed in AnnexC can also be used with pipes conforming to this standard, provided they conform to the requirements for joint dimensions given in Clause6 and to the requirements in Table11. NOTE5 Joints and adhesives are considered to be part of the system as covered in the scope. NOTE6 Products conforming to this standard may be submitted to national requirements on fire regulation.