ISO 5356-1:2015

Overview

ISO 5356-1:2015 - Anaesthetic and respiratory equipment - Conical connectors - Part 1: Cones and sockets defines dimensional and gauging requirements for conical cones and sockets used to join anaesthetic and respiratory equipment. The standard covers standard connector sizes used across breathing systems, anaesthetic gas scavenging systems and vaporizers and specifies how cones and sockets are measured and tested for interchangeability and performance. Cones and sockets are treated as connection features, not standalone medical devices.

Key topics and technical requirements

• Connector sizes covered: 8.5 mm and 11.5 mm (neonatal/paediatric), 15 mm and 22 mm (general breathing systems), 23 mm (vaporizers only), 30 mm (connection to scavenging systems).
• Dimensional requirements: Figure 1 and Table 1 define taper, lengths and minimum internal diameters for metal and non‑metal materials. Metal parts must meet the specified dimensions; plastics have gauging requirements.
• Gauging and test gauges: Annex A (non‑metal) and Annex E (metal) specify plug and ring test gauges and tolerances for functional checking. For non‑metal connectors, gauging is performed while applying axial and rotational forces.
• Latching sockets (22 mm): Design and performance requirements for 22 mm latching sockets include engagement with a cone recess and tests for security and leakage.
• Performance tests:
  • Security of engagement: withstand an axial separation force of (50 ± 5) N for 10 s (Annex B). If rotation is restricted, a torque of (25 ± 5) N·cm may also be applied.
  • Leakage: maximum permitted leakage is 5 ml/min (corrected to 20 °C and 101.3 kPa) at an internal pressure of (8 ± 0.5) kPa (Annex C).
  • Drop test: must meet engagement and leakage requirements after five drops from 1 m onto a hardwood surface (Annex D).
• Environmental/test conditions: Specific conditioning temperatures and humidity are given for different tests (e.g., 35 ± 3 °C and ≥80% RH for some latching tests).

Applications and practical value

• Ensures interchangeability of breathing system components from different manufacturers, reducing risk of incompatible fittings.
• Guides manufacturers and designers of anaesthetic machines, breathing circuits, vaporizers and scavenging systems on connector geometry and testing.
• Supports quality control and type testing in production and test laboratories using plug/ring gauges and the specified functional tests.
• Helps clinicians and biomedical engineers choose components that comply with international sizing and safety expectations.

Who uses this standard

• Medical device manufacturers (breathing circuits, masks, vaporizers)
• Test laboratories and conformity assessors
• Hospital biomedical engineering and procurement teams
• Regulatory bodies and standards committees

Related standards

• ISO 5356-2 (screw-threaded weight-bearing connectors)
• ISO 5367 (breathing sets and connectors) - referenced for related device interface requirements

Keywords: ISO 5356-1:2015, conical connectors, cones and sockets, anaesthetic and respiratory equipment, 22 mm latching socket, plug and ring gauges, breathing systems, vaporizers, anaesthetic gas scavenging.