BS 7734:1994

Committees responsible
National foreword
Introduction
Specification
1. Scope
2. Normative references
3. Definitions
4. General requirements
5. Breathing systems either supplied complete or
     assembled in accordance with manufacturers'
     instruction
6. Adjustable pressure-limiting (APL) valves
7. Circle absorber assemblies
8. Unidirectional valves
9. Pressure-monitoring
10. Location of breathing system components
11. Marking
12. Information to be provided by manufacturer
Annexes
A. (normative) Type test methods
B. (informative) Breathing system classification
Figures
1. Markings for carbon dioxide absorbers and circle
     absorber assemblies
A.1 Arrangement of apparatus to test resistance to
     flow of APL valves
A.2 Arrangement of apparatus to test for leakage from
     APL valves
A.3 Arrangement of apparatus to test for reverse flow
     through unidirectional valves
A.4 Arrangement of apparatus to test for opening
     pressure of unidirectional valves
B.1 Legend of symbols for breathing attachments used
     in figures B.2 and B.3
B.2 Circle system showing position of segments
B.3 Illustration of use of graphical symbols in circle
     absorption system

Covers circle absorption breathing systems supplied complete or for assembly by the user, and some breathing attachments, e.g. CO₂ absorbers, uni-directional and APL valves. Excludes anaesthesia ventilators and dental analgesia systems.