BS/EN 138-1994 pdf download.Respiratory protective devices — Fresh air hose breathing apparatus for use with full face mask, half mask or mouthpiece assembly — Requirements, testing, marking.
6.6 Connection between apparatus and faceplece
The connection between the breathing apparatus and the facepiece may be achieved by a permanent, special or thread type connector. If a threafi connector is used it shalt comply with the requirements of one of the following standards:
EN 148-1 for breathing apparatus without positive pressure;
EN 148-2 for closed-circuit breathing apparatus; EN 148-3 for breathing apparatus with positive pressure.
If any other thread type connector is used it shall not be possible to connect it with the above mentioned threads.
The standard thread according to EN 148-1 shall not be used for apparatus with positive pressure, closed-circuit apparatus and diving apparatus. The thread according to EN 148-2 shall not be used for open-circuit devices and diving apparatu.s. The thread according to EN 148-3 shall not be used for apparatus without positive pressure, closed-circuit apparatus and diving apparatus.
6.7 Body harness, belt and breathing bag
6.7.1 A body harness or belt shall be provided to which the breathing hose and breathing bag, if fitted, shall be attached. Buckles shall not slip, Thsting in accordance with 7.2 and 7.4.
6.7.2 It shall not be possible to connect the air supply hose directly to the breathing hose or facepiece.
‘Thsting in accordance with 7.2.
6.7.3 When a breathing bag is fitted It shall be protected against damage.
‘Thsting in accordance with 7.2.
6.8 ResIstance to temperature
6.8.1 After storage in accordance with 7.7.1 all other performance requirements of this standard shall be met.
6.8.2 After storage in accordance with 7.7.1, the apparatus shall comply with 6.19 and shall continue to operate satisfactorily as assessed by the procedures of 7.7.2 and 7.7.3.
6.8.3 Apparatus spedfically designed for temperatures beyond the limits for storage or use given in 7.7.1 shall be tested and marked accordingly.
6.9 Flammability
When tested in accordance with 7.8 all exposed components of the apparatus shall not continue to burn for more than 5 s after removal from the flame.
6.10 AIr supply system
6.10.1 UnassIsted air supply
The air supply hose shall be fitted with a strainer at the free end to exclude debris. Provision shall be made for securely anchoring the free end of the hose and strainer.
Thsting in accordance with 7.2 and 7.4. 6.10.2 Manually assisted air supply Manually assisted blowers shall be capable of being operated continuously by one man at the manufacturer’s minimum air supply rate for at least 30mm.
It is recommended that apparatus provided with a manually assisted air supply should incorporate a breathing bag or similar device.
6.10.3 Power operated air supply Rotary type blowers shall be capable of maintaining a positive air pressure with either direction of rotation, or they shall be designed to operate in one direction only. Where the blower can operate In either direction the direction of operation in which the blower delivers the lesser volume of air shall be used in the tests.
6.11 AIr supply hose
6.11.1 Resistance to collapse
6.11.1.1 (Jnass’Lcted apparatus When unassisted apparatus Is tested in accordance with 7.9 with an applied load of 1000 N the increase in breathing resistance shall not exceed 1 mbar
6.11.2.2 Manually assisted or pour operated apparatus
When manually assisted or power operated apparatus is tested in accordance wIth 7.10 the reduction in air flow shall not exceed 10 % when an applied force of 125 Nlsused forciass loran applied force of 250 N is used for class 2.
6.11.3 Strength
The air supply hose, couplln and continuous flow valve (If present) shall not separate when tested In accordance with 7.11.
6.11.4 Flex1blUt
The air supply hose shall be capable of being wound on to a drum 500 mm in diameter.
ThsUng In accordance with 7.2
6.11.5 Heat resistance
Air supply hose claimed to be resistant to damage from contact with hot surfaces and boiling water shall be tested in accordance with 7.12 and shall show no signs of damage or indications of failure and the air quality shall not he significantly affected.
6.11.6 Electrostatic properties
Air supply hoses claimed to be antistatic, when tested in accordance with EN 28031 makIng connections to the couplings shall have an electrical resistance measured complete with couplings that is eater than 10 U and less than
io Q.
6.12 Breathing hose
Breathing hoses shall be flexible and non-kinking. The breathing hoses shall permit free head movement and shall not restrict or close off the air supply under chin or arm pressure during practical performace tests.
lèstlng in accordance with 7.2 and 7.4. 6.13 Overflow valve
Where a standard thread (EN 148-1) is used as an equipment connector and where the equipment is manually assisted or power operated an overflow valve shall be fitted. It shall be protected against or be resistant to dirt and mechanical damage.BS/EN 138-1994 pdf download.
BS/EN 138-1994 pdf download
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