Small knowledge points of fire fighting technology and equipment.

(1) What is the purpose and specification of the guide rope? How to use it safely? Guide ropes are mainly used for firefighters to control the attack, evacuation direction or keep in touch with the outside when they enter dangerous areas with dense smoke or low visibility and complex terrain and building structures, including guide ropes for teams and personal guides. The length of the guide rope for the team is 60 meters (it can be determined according to the needs, and can be extended appropriately). There is a set of drooping rope head marks every 3 meters on the rope. The short rope head with knots (length 50 mm) indicates the direction of entering the scene. The long rope end (100 mm long) of the knot indicates the direction of withdrawal. The length of the personal guide rope is 6 meters. Before use, each connection point must be firmly connected, and the rope sign indicating the direction of entry and exit must be kept in mind (it can be used with other protective equipment as required).

(2) What is the purpose and method of use of the slow-down device? The descending device can be used for firefighters or other personnel to slowly descend from a height to save life. It can be used repeatedly to save people continuously. It consists of hooks or rings, speed controllers, life belts and safety ropes. When in use, put the lifebelt at one end of the safety rope under the armpit of the rescued person, and fix the other end on the object near the window or balcony. It has a round shape, weighs 2.7 kg, and can reach up to 30 meters in length.

(3) How to use insulating shears, insulating gloves and insulating boots?

Insulation shears for fire fighting are used for firefighters to cut wires and cut off power when fighting a fire. There are two types: large and small. There are two types of insulating gloves, rubber products and latex products, divided into 12KV and 5KV. They are mainly used to operate high and low voltage power equipment. 12KV insulated gloves are auxiliary safety equipment when the voltage is above 1KV, and basic safety equipment when the voltage is below 1KV; 5KV insulating gloves are prohibited when the voltage is above 1KV, auxiliary safety equipment when the voltage is below 1KV, and 0.25KV as basic safety equipment. Insulating boots are auxiliary safety devices used to maintain insulation from the ground, and are also basic safety devices for protecting step voltage.

(4) How to classify fire pumps?

(1) According to the purpose and the object of allocation:

① Vehicle fire pump (installed on the chassis of the fire truck).

②Hand-carry motorized fire pump (which can be moved by hand).

③Fixed fire pump (fixedly installed inside and outside the building, used for fixed fire extinguishing system or other fire fighting facilities).

④Towing the fire pump (it can be towed by manpower or motor vehicles).

⑤ Marine fire pump (installed on ships and fire boats).

⑥Agricultural fire pump (matched with agricultural power machinery such as tractors, it can be used for farmland irrigation and drainage, and it can also be used for rural fire fighting).

(2) According to the conveyed medium:

①Fire water pump (mainly used to transport water or a mixture of water and foam).

②Foam liquid pump (mainly used to transport foam solution).

③Diversion pump (mainly used as an accessory to the centrifugal fire pump, used to remove the air in the water pump and suction pipe to form a vacuum and divert water).

(3) According to its outlet pressure:

① Normal pressure fire pump. The outlet pressure is less than or equal to 16×105 Pa.

②Medium pressure fire pump. The outlet pressure is greater than 16×105 Pa and less than or equal to 25×105 Pa.

③High pressure fire pump. The outlet pressure is greater than 25×105 Pa.

④Medium and low pressure fire pump. The outlet pressure has both the pressure of the normal pressure fire pump and the pressure of the medium pressure fire pump.

⑤High and low pressure fire pump. The outlet pressure has not only the pressure of the normal pressure fire pump, but also the pressure of the high pressure fire pump.

(5) What is a centrifugal pump? What parts does it consist of? Why is a water diversion device installed on the centrifugal pump?

A centrifugal pump is a hydraulic machine that transports liquids by centrifugal force. There are mainly three types of single-stage centrifugal fire pumps, two-stage centrifugal fire pumps and centrifugal vortex fire pumps. The centrifugal pump is composed of impeller, pump shaft, pump casing (front and rear cover), suction pipe, outlet pipe and shaft sealing device.

Because the necessary condition for the centrifugal pump to work is to fill the pump with water first. When starting, the air must be discharged first, and then the water can be sucked in. However, the mass of air is much smaller than that of water. The centrifugal force generated when the impeller drives the air in the pump to rotate is much smaller than the centrifugal force generated when the water rotates. The lower the centrifugal force, the smaller the pressure difference between the center and the outer edge of the impeller in the pump, which is not enough to make the water source rise to the center of the impeller, and the pump cannot suck water. Therefore, fire trucks are equipped with water diversion devices (vacuum pumps) on centrifugal pumps.