ISO 5356-1:2015 is the internationally recognized standard titled Anaesthetic and respiratory equipment — Conical connectors — Part 1: Cones and sockets. Published by the International Organization for Standardization (ISO), it establishes precise dimensional requirements, gauging methods, and performance criteria for conical connectors used in breathing systems, vaporizers, anaesthetic workstations, and anaesthetic gas scavenging systems.
The standard’s core objective is to enhance patient safety by ensuring reliable interconnections while preventing hazardous misconnections (e.g., linking a breathing circuit to an intravenous line). It applies to manufacturers, testing laboratories, and regulatory bodies worldwide.
Key Connector Sizes and Applications
The standard defines specific sizes with strict tolerances:
- 8.5 mm — Primarily for neonatal and paediatric breathing systems
- 11.5 mm — Additional paediatric applications
- 15 mm — Common for patient end of breathing circuits
- 22 mm — Standard for adult breathing systems and expiratory limbs
- 23 mm — Dedicated to vaporizer connections (not interchangeable with breathing systems)
- 30 mm — Used for anaesthetic gas scavenging system interfaces
Special performance requirements apply to 22 mm latching sockets to ensure secure engagement under clinical conditions.
Example of a typical conical connector engagement tester setup (universal apparatus for applying axial force and rotation per ISO 5356-1 requirements).
Core Requirements and Gauging Principles
Connectors must mate correctly under defined forces (typically 35 N for smaller sizes and 50 N for 22 mm and 30 mm) with limited rotation. Gauges verify both minimum and maximum dimensional limits.
Two main gauge categories exist:
- Non-metal connectors (e.g., plastic/polymer) — Normative requirements in Annex A
- Metal connectors (e.g., reusable metal components) — Informative guidance in Annex E
Gauges feature stepped designs to check go/no-go conditions and are manufactured from hardened, precision materials for long-term accuracy.
Examples of ISO 5356-1 Annex A plug and ring gauges (22 mm and 15 mm sizes shown with reference markings for male/female verification).
Close-up of a typical 8.5 mm plug gauge used for neonatal connector verification.
Recommended Full Set of Testing Equipment
A complete ISO 5356-1 compliant laboratory setup includes:
1. Non-Metal Conical Connector Gauges (Annex A)
| Size | Gauge Type | Purpose | Reference Figure |
|---|---|---|---|
| 8.5 mm | Plug Gauge | Male cone dimensional check | Fig A.1 |
| 8.5 mm | Ring Gauge | Female socket dimensional check | Fig A.1 |
| 11.5 mm | Plug Gauge | Paediatric male verification | Fig A.1 |
| 11.5 mm | Ring Gauge | Paediatric female verification | Fig A.1 |
| 15 mm | Plug Gauge | General breathing male | Fig A.1 |
| 15 mm | Ring Gauge | General breathing female | Fig A.1 |
| 22 mm | Plug Gauge | General breathing male | Fig A.1 |
| 22 mm | Ring Gauge | General breathing female | Fig A.1 |
| 30 mm | Plug Gauge | Scavenging system male | Fig A.1 |
| 30 mm | Ring Gauge | Scavenging system female | Fig A.1 |
Set of precision ring and plug gauges in hardened steel for metal and non-metal connector verification.
2. General Connector Tester (Clause 3.1.2 Engagement)
This apparatus applies controlled axial force while allowing rotation to confirm proper mating without excessive play or binding.
- Typical Model Example: KINGPO KP-5361
- Key Function: Verifies basic dimensional and engagement compliance across all sizes.
3. Reliability Test Device for 22 mm Latching Sockets (Annex B)
Latching connectors require additional tests for security of engagement, including axial pull (50 N), rotation, and simulated clinical stresses.
- Typical Model Example: KINGPO KP-5362
- Key Function: Ensures latching mechanisms resist accidental disconnection.
4. Metal Conical Connector Gauges (Annex E)
| Size | Gauge Type | Purpose | Reference Figure |
|---|---|---|---|
| 8.5 mm | Plug Gauge | Metal male cone | Fig E.1 |
| 8.5 mm | Ring Gauge | Metal female socket | Fig E.1 |
| 15 mm | Plug Gauge | Metal general male | Fig E.1 |
| 15 mm | Ring Gauge | Metal general female | Fig E.1 |
| 22 mm | Plug Gauge | Metal general male | Fig E.1 |
| 22 mm | Ring Gauge | Metal general female | Fig E.1 |
| 23 mm | Plug Gauge | Vaporizer-specific male | Fig E.1 |
| 23 mm | Ring Gauge | Vaporizer-specific female | Fig E.1 |
| 30 mm | Plug Gauge | Metal scavenging male | Fig E.1 |
| 30 mm | Ring Gauge | Metal scavenging female | Fig E.1 |
Why KINGPO Equipment Excels for ISO 5356-1 Compliance
KINGPO Technology specializes in medical testing instruments aligned with ISO 5356-1:2015, IEC 60601 series, and related standards. Their gauges and testers feature:
- High-precision hardened materials
- Third-party metrology calibration support
- User-friendly designs for repeatable laboratory testing
- Proven reliability in global medical device certification labs
For authoritative implementation, always refer to the official ISO 5356-1:2015 document. KINGPO provides trusted, high-quality solutions to help manufacturers and test houses achieve full compliance efficiently. Contact KINGPO experts for guidance on building your complete conical connector testing capability.
