AIR-LINE MASKS

The air-line mask (fig. 6-31) is part of all ship's repair party locker allowance. The air-line mask

Figure 6-31.-Air-line mask with buddy fitting

.

MUST NOT be used to fight fires. However, it may be used to enter smoke-filled spaces to rescue personnel.

The air-line mask is a demand-flow, air-line respirator with a speaking diaphragm, monocular lens with adjustable head harness, breathing tube and belt-mounted demand regulator with male and female (buddy) quick-disconnect fittings. A 25-foot length of hose with male and female quick-disconnect fittings is provided for use with the air-line mask. This hose can be used to connect to the demand regulator fitting and a low-pressure air supply, or to a compressed air cylinder with an intervening air regulator and air filter. The air filter consists of a particulate element and a refillable charcoal cartridge.

A positive pressure of 30 to 125 psi must be maintained at the demand regulator at all times. The maximum length of hose that may be used with the air-line mask is 250 feet. If the compressor room's air is contaminated with smoke or other gases, secure the compressor and use another compressor that is in a compartment that has clean air. The hose is flammable and may get tangled up with wreckage. If the hose does get tangled, it could pull the mask off your face.

To use the air-line mask, follow these procedures:

1. Check the regulator on the compressed air cylinders, if used, to ensure that it is closed.

2. Open the valves on the cylinders, or connect the hose up to the low-pressure air system.

3. Open the regulator on the cylinders by turning the adjustment handle clockwise until the desired reading or rate of flow is obtained. DO NOT exceed 125 psi when using the compressed gas cylinders.

4. Don the safety belt.

5. Grasp the mask with both hands. Slip the facepiece on your chin first. Then adjust the head straps as follows:

a. Ensure that the straps lie flat against your head.

b. Tighten the lower (neck) straps.

c. Tighten the side straps. Do not touch the forehead (front) strap.

d. Place both hands on the head harness pad. Push the pad down toward your neck.

e. Repeat steps b and c.

f. Tighten the forehead strap.

g. Test for a tight fit of the facepiece by squeezing the breathing tube and taking a deep

breath. The facepiece must collapse against your face or be readjusted until it does.

6. Take a deep breath to ensure there is no blockage of the airflow.

7. Push the male quick-disconnect fitting into the female fitting of the manifold.

8. Inhale deeply to ensure there is a sufficient airflow.

9. If you are forced to evacuate a space, you can do so by disconnecting the female portion of the quick-disconnect fitting and leave the air-line mask on. The female fitting is equipped with an automatic shutoff. Therefore, it is not necessary to secure the low-pressure air system or the cylinders when making an emergency evacuation of the space.

10. When leaving a smoked-filled space without any type of respiratory equipment other than the air-line mask, get as close to the exit as possible. When you run out of hose, take a couple of deep breaths, hold your breath, disconnect the female quick-disconnect fitting, and exit the space immediately.

Do not remove the mask until you are out of the smoke-filled space.

Further information on the air-line mask is available in the Naval Ships' Technical Manual, chapter 079, volume 2.