ISO 727-2:2005

Overview

ISO 727-2:2005 specifies the dimensional requirements for plain sockets (both cylindrical and conical) in fittings made from PVC‑U, PVC‑C or ABS for the inch-based pipe series. Dimensions are given in millimetres and are intended for fittings that are joined to matching pipes by solvent cementing for use under pressure. The standard ensures that the resulting solvent-welded joint does not require mechanical anchorage and supports consistent interchangeability between manufacturers.

Key topics and technical requirements

• Material scope: unplasticized poly(vinyl chloride) (PVC‑U), chlorinated PVC (PVC‑C), and acrylonitrile/butadiene/styrene (ABS).
• Socket types: definitions and requirements for cylindrical (parallel) sockets and conical (tapered) sockets.
• Dimensional data: tables of minimum socket lengths, mean inside diameters (measured at the mid‑point of socket depth), socket mouth/root dimensions and permissible out‑of‑roundness for each nominal inch size. Separate tables apply for PVC‑U/PVC‑C and for ABS.
• Reference sizing: socket sizes are based on nominal outside diameters according to ISO 161‑2 (inch‑based series).
• Manufacturing notes: allowance for slight mould‑taper on “cylindrical” sockets and a shrinkage note for PVC‑C socket lengths; maximum included taper angles for cylindrical sockets are specified.
• Marking: product marking must reflect the socket type (cylindrical or conical) as required in the relevant product standard.
• Installation advice: the document strongly recommends consulting the fittings manufacturer for the appropriate solvent cement selection depending on socket type.

Applications and users

ISO 727-2:2005 is practical for:

• Fittings manufacturers designing and moulding PVC‑U, PVC‑C or ABS fittings to ensure dimensional conformity and interchangeability.
• Product designers and specifiers who need standardised socket dimensions for pressure pipe systems using inch‑based sizes.
• Plumbing and mechanical engineers specifying solvent‑welded pipe systems for water, industrial fluids and non‑hazardous pressurised services.
• Quality and compliance teams, testing laboratories, and procurement groups verifying conformance to international standards.
• Installers who require clarity on socket types and solvent cement compatibility.

Related standards

• ISO 161-2: Thermoplastics pipes - nominal outside diameters and nominal pressures - Inch-based series (sizing reference).
• ASTM D2467, ASTM F439, BS 4346‑1, BS 5392‑1 - referenced normative/related documents used as data sources for tables and test practice.

Keywords: ISO 727-2:2005, PVC‑U fittings, PVC‑C fittings, ABS fittings, plain sockets, inch-based series, solvent cementing, cylindrical socket, conical socket, pipe under pressure.