(a) The completely assembled respirator will be worn in a chamber containing 0.1 0.025 percent isoamyl acetate vapor, the intake of the hose will be connected to a suitable source of respirable air, and not more than 25 percent of the hose length will be located in isoamyl acetate-free air.
(b) The test will be conducted at the minimum pressure with the maximum hose length and will be repeated at the maximum pressure with the minimum hose length.
Sec. Table to Subpart J of Part 84
Table 8--Air-Supply-Line Requirements and Tests
[42 CFR part 84, subpart J]----------------------------------------------------------------------------------------------------------------
Requirements for the air-supply lines of the indicated type of supplied-air
respirators
Specific requirements ----------------------------------------------------------------------------
Type A Type B Type C----------------------------------------------------------------------------------------------------------------Length of hose..................... Maximum of 91 m. (300 Maximum of 23 m. (75 Maximum of 91 m. (300 feet)
feet), in multiples feet) in multiples of in multiples of 7.6 m. (25
of 7.6 m. (25 feet). 7.6 m. (25 feet). feet). It will be
permissible for the
applicant to supply hose
of the approved type of
shorter length than 7.6 m.
(25 feet) provided it
meets the requirements of
the part.Air flow........................... None.................. None.................. The air-supply hose with
air regulating valve or
orifice shall permit a
flow of not less than 115
liters (4 cubic feet) per
minute to tight-fitting
and 170 liters (6 cubic
feet) per minute to loose-
fitting respiratory-inlet
coverings through the
maximum length of hose for
which approval is granted
and at the minimum
specified air-supply
pressure. The maximum flow
shall not exceed 425
liters (15 cubic feet) per
minute at the maximum
specified air-supply
pressure with the minimum
length of hose for which
approval is granted.Air flow........................... ......do.............. ......do.............. The air-supply hose,
detachable coupling, and
demand valve of the demand
class or pressure-demand
valve of the pressure-
demand class for Type C
supplied-air respirators,
demand and pressure-demand
classes, shall be capable
of delivering respirable
air at a rate of not less
than 115 liters (4 cubic
feet) per minute to the
respiratory-inlet covering
at an inhalation
resistance not exceeding
50 millimeters (2 inches)
of water-column height
measured in the
respiratory-inlet covering
with any combination of
air-supply pressure and
length of hose within the
applicant's specified
range of pressure and hose
length. The air-flow rate
and resistance to
inhalation shall be
measured while the demand
or pressure-demand valve
is actuated 20 times per
minute by a source of
intermittent suction. The
maximum rate of flow to
the respiratory-inlet
covering shall not exceed
425 liters (15 cubic feet)
per minute under the
specified operating
conditions.
Air-regulating valve............... ......do.............. ......do.............. If an air-regulating valve
is provided, it shall be
so designed that it will
remain at a specific
adjustment, which will not
be affected by the
ordinary movement of the
wearer. The valve must be
so constructed that the
air supply with the
maximum length of hose and
at the minimum specified
air-supply pressure will
not be less than 115
liters (4 cubic feet) of
air per minute to tight-
fitting and 170 liters (6
cubic feet) of air per
minute of loose-fitting
respiratory inlet
coverings for any
adjustment of the valve.
If a demand or pressure-
demand valve replaces the
air-regulating valve, it
shall be connected to the
air-supply at the maximum
air pressure for which
approval is sought by
means of the minimum
length of air-supply hose
for which approval is
sought. The outlet of the
demand or pressure-demand
valve shall be connected
to a source of
intermittent suction so
that the demand or
pressure-demand valve is
actuated approximately 20
times per minute for a
total of 100,000
inhalations. To expedite
this test, the rate of
actuation may be increased
if mutually agreeable to
the applicant and NIOSH.
During this test the valve
shall function without
failure and without
excessive wear of the
moving parts. The demand
or pressure-demand valve
shall not be damaged in
any way when subjected at
the outlet to a pressure
or suction of 25 cm. (10
inches) of water gage for
2 minutes.Noncollapsibility.................. The hose shall not Same as Type A........ None.
collapse or exhibit
permanent deformation
when a force of 90
kg. (200 pounds) is
applied for 5 minutes
between 2 planes 7.6
cm. (3 inches) wide
on opposite sides of
the hose.Nonkinkability..................... None.................. None.................. A 7.6 m. (25 foot) section
of the hose will be placed
on a horizontal-plane
surface and shaped into a
one-loop coil with one end
of the hose connected to
an airflow meter and the
other end of the hose
supplied with air at the
minimum specified supply
pressure. The connection
shall be in the plane of
the loop. The other end of
the hose will be pulled
tangentially to the loop
and in the plane of the
loop until the hose
straightens. To meet the
requirements of this test
the loop shall maintain a
uniform near-circular
shape and ultimately
unfold as a spiral,
without any localized
deformation that decreases
the flow of air to less
than 90 percent of the
flow when the hose is
tested while remaining in
a straight line.Strength of hose and couplings..... Hose and couplings Same as Type A........ Hose and couplings shall
shall not separate or not exhibit any separation
fail when tested with or failure when tested
a pull of 113 kg. with a pull of 45 kg. (100
(250 pounds) for 5 pounds) for 5 minutes and
minutes. when tested by subjecting
them to an internal air
pressure of 2 times the
maximum respirator-supply
pressure that is specified
by the applicant or at 173
kN/m. 2 (25 pounds per
square inch) gage,
whichever is higher.
Tightness.......................... No air leakage shall None.................. Leakage of air exceeding 50
occur when the hose cc. per minute at each
and couplings are coupling shall not be
joined and the permitted when the hose
joint(s) are immersed and couplings are joined
in water and and are immersed in water,
subjected to an with air flowing through
internal air pressure the respirator under a
of 35 kN/m. 2 (5 pressure of 173 kN/m. 2
pounds per square (25 pounds per square
inch) gage. inch) gage applied to the
inlet end of the air-
supply hose, or at twice
the maximum respirator-
supply pressure that is
specified by the
applicant, whichever is
higher.Permeation of hose by gasoline..... The permeation of the Same as for Type A.... Same as for Type A, except
hose by gasoline will the test period shall be 1
be tested by hour.
immersing 7.6 m. (25
feet) of hose and one
coupling in gasoline,
with air flowing
through the hose at
the rate of 8 liters
per minute for 6
hours. The air from
the hose shall not
contain more than
0.01 percent by
volume of gasoline
vapor at the end of
the test.Detachable coupling................ None.................. None.................. A hand-operated detachable
coupling by which the
wearer can readily attach
or detach the connecting
hose shall be provided at
a convenient location.
This coupling shall be
durable, remain connected
under all conditions of
normal respirator use, and
meet the prescribed tests
for strength and tightness
of hose and couplings.----------------------------------------------------------------------------------------------------------------