BS EN 142-2002 pdf download.Respiratory protective devices-Mouthpiece assemblies Requirements , testing ,marking.
Following the conditioning in accordance with 7.4 and after being allowed to return to ambient temperature the mouthpiece assembly shall show no appreciable deformation and any incorporated threaded connector to EN 148-1 or EN 148-2 shall be gauged and shall comply with the appi-opriate standard.
Testing shall be done in accordance with 7.3.
6.7 Flammability
Parts of the mouthpiece assembly that might be exposed to a flame during use shall not burn or continue to burn for more than 5 s after removal from the flame.
Testing shall be done in accordance with 7.3 and 7.5,
6.8 Demountable parts
All demountable connections shall be readily connected and secured, where possible by hand. Any means of sealing used shall be retained in position when the connection is disconnected during normal maintenance. Testing shall be done in accordance with 7.3 and 7.13.
6.9 Replaceable components
Unless integral with the mouthpiece assembly the following components (if fitted) shall be replaceable:
Head harness, connector(s), inhalation and exhalation valves.
Testing shall be done in accordance with 7.3.
6.10 Head harness
The head harness shall be designed so that the mouthpiece assembly can be donned and removed easily.
Testing shall be done in accordance with 7.13.
The head harness shall be adjustable or sell-adjusting and shall hold the mouthpiece assembly firmly and comfortably in position.
Testing shall be done in accordance with 7.13.
Each strap of the head harness, buckles and other adjusting means shall withstand a pull of 50 N applied for 10 $ in the direction of pulling when the facepiece is donned. No breaks or sliding of the straps shall occur.
The requirement applies to the buckles and attachment lugs as well as to the straps.
Testing shall be done in accordance with 7.3, 7.11 and 7.13.
The connection between the mouthpiece body and the connector shall be sufficiently robust to withstand axially a tensile force of 50 N.
Testing shall be done in accordance with 7.7.
6.11.2 Thread connection according to EN 148-1
This thread connection may be used as the mouthpiece assembly connection for all respiratory protective devices. except closed-circuit breathing apparatus and positive pressure demand bieathing apparatus.
If this thread connection is used then the relevant requirements of EN 148-1 shall be satisfied.
Testing shall be done in accordance with 7.3.
6.11.3 Thread connection according to EN 148-2
This thread connection may be used as the mouthpiece assembly connection for closed-circuit breathing apparatus.
If this thread connection is used then the relevant requirements of EN 148-2 shall be satisfied. Testing shall be done in accordance with 7.3.
6.12 Inhalation valves and exhalation valves (if fitted)
6.12.1 General
Valve assemblies shall be such that they can be readily maintained and correctly replaced.
It shall not be possible to fit an exhalation valve assembly into the inspiratory circuit or an inhalation valve assembly into the exhalation circuit.
Inhalation and exhalation valve assemblies, sub-assemb4ies and piece parts that are by the manufacturer designed to be identical, are acceptable.
Differently designed inhalation and exhalation valves are acceptable if a precise and comprehensible description is given in the information manual supplied by the manufacturer. The description in the information manual supplied by the manufacturer should be supported by illustrations (photographs, drawings) on how to assemble the unit correctly.
To enable correct assembly, the parts shall be be precisely and comprehensibly described or marked.
An appropriate method of checking correct assembly shall be described, e.g. visual inspection, check by the
wearer, test by maintenance personnel, etc.
A mouthpice assembly with centre thread connection to EN 148-2 shall not have valves.
Testing shall be done in accordance with 7.3.
6.12.2 Inhalation valve(s)
If a thread connection according to EN 148-1 is used, an inhalation valve shall be incorporated in the mouthpiece assembly. Where the facepiece is intended to be used with filters it shall be provided with an integral inhalation valve, if there is no valve in the fitter.
Inhalation valve(s) shall function correctly in all orientations and shall meet the requirements of 6.14. Testing shall be done in accordance with 7.12 and 7.13.
6.12.3 Exhalation valve(s)
Exhalation valve(s) shall function correctly in all orientations and shall meet the requirements of 6.14.
Testing shall be done in accordance with 7.12 and 7.13.
The mouthpiece assembly except one with a centre thread connection to EN 148-2 shall have at least one exhalation valve or appropriate means to allow the escape of exhaled air and, where applicable, any excess air delivered from a supplied air source.
Testing shall be done in accordance with 7.3.
Exhalation valve(s) shall be protected against or be resistant to dirt and mechanical damage. They may be shrouded or include any other device that may be necessary to comply with 6.13.
Exhalation valve(s) shall continue to operate correctly after a continuous exhalation flow of 300 1/mm over a period of 30 s and meet the requirements of 6.14.
Testing shall be done in accordance with 7.8.
When the exhalation valve housing is attached to the mouthpiece body, it shall withstand axially a tensile force of 50 N applied for 10 S.
Testing shall be done in accordance with 7.9.
The inward leakage through the exhalation valve(s) shall not exceed 0,01 %.BS EN 142-2002 pdf download.