Safe operating procedure for positive pressure air breathing apparatus

(1) Preparation before use

① Before the breathing apparatus is installed, check whether the O-shaped sealing ring connected to the live cap is in the correct position and whether it is damaged.

(2) Before the respirator is used, there must be enough air in the cylinder (the cylinder pressure is generally not less than 25MPa), and it is immediately inflated below 20MPa.

③ Air tightness check

Press the off switch of the supply valve in the off position.

Slowly turn on all cylinders to fill the system with pressure, and a short alarm sound will be heard.

Turn off the cylinder switch and observe the pressure indication. The pressure drop value shall not exceed 4MPa within 5 minutes.

④ alarm test

Block the air outlet of the supply valve with your finger, press the center button of the protective cap, and slowly remove your finger to keep the pressure slowly decreasing.

Observe the pressure indication, when the set pressure (4-6MPa) is reached, the alarm should sound an alarm.

After completing the alarm test, press the supply valve shutoff switch to close it.

⑤ The supply valve is connected with the mask

Check the O-ring seal on the full hood interface and supply valve, and keep it clean and undamaged.

Insert supply valve into mask port until locked.

Check whether the supply valve is securely installed.

(2) Wearing operation method

① Facing the top of the gas cylinder (bald end), grasp the right belt with your left hand, grasp the left belt with your right hand, and use force to put the gas cylinder on your back and adjust and straighten it.

② Fasten the buckle of the chest strap, tighten the chest strap, and pull the shoulder strap with both hands.

③ Hang the mask sling from the back of the neck, put the mask over the head and upright.

④ Pull back the five fixed straps on the mask with both hands at the same time, so that the mask is close to the face.

⑤ Check the air tightness of the mask: if you feel difficulty breathing, it means that the seal is good; Otherwise, continue to tighten the five fastening straps on the mask.

⑥ Open the cylinder valve and breathe normally.

(3) Wear and use

① Observe the indicating value of the pressure gauge at any time during use. If there are other discomfort symptoms such as dyspnea, stop the operation immediately, evacuate to the safe area in the fastest and safest way, and check the respirator as a whole.

When the indicating value of the pressure gauge is in the range of 4-6MPa, the alarm should be heard, and the fastest and safest way to evacuate to the safety zone at this moment.

(3) If you do not hear the alarm sound, but observe the pressure gauge indicating 4-6MPa, you should immediately withdraw to the safety zone and replace the air cylinder.

(4) After use notice

① Relax the headband of the mask, put the supply valve in the closed state, and remove the mask.

② Turn off the gas cylinder switch.

③ Undo the belt, release the shoulder strap, and then take off the respirator and put it in the appropriate place. At this time, do not drop the respirator at will to avoid damage.

(5) Precautions

① In the process of use, when the pressure drops to 4-6MPa, the alarm sounds (noisy environment can not be too dependent on the sound alarm, should be observed at any time the indicator value of the pressure gauge), to remind the user to leave the scene in time.

② The gas cylinder can only use pure air, not oxygen, the respirator should be kept by a special person, and should be stored in a cool and dry place.

③ When used, the gas in the cylinder should not be all used up, and the residual pressure of not less than 0.05MPa should be retained, and the full bottle is not allowed to be exposed.

④ The pressure reducer shell and 0-shaped sealing ring should be regularly purged with compressed air. If the sealing ring is damaged and aging, it should be replaced.

⑤ When the air respirator is not in use, it should be placed in the safe deposit box or storage shelf, and it should not be under pressure when stored, and it should be stored in a clean and dry room, which can not be eroded by sunlight exposure and toxic and harmful gases and dust.

Under normal circumstances, the air supply valve is strictly prohibited to disassemble.

⑦ Beard, sideburns or wearing glasses will affect the tightness of the respirator mask, and special attention should be paid when using.

From a design point of view, the positive pressure breathing apparatus cannot be used underwater.