Hydrant And Fire Fighting System Planning

Hydrant And Fire Fighting System Planning

Problem Basic

In the implementation of the construction of a building, it is very necessary for building planning including architectural, structural and mechanical and electrical planning in order to create a building that can be used in accordance with the function and purpose of the building.

The existing mechanical system in the building is one of the components needed in the manufacture of buildings, in general to get a comfortable and healthy building to be used for a long period of time by its occupants without destroying the architectural beauty of the building and to support all the needs and activities required. takes place in the building.

Fire is something that often happens in factories and institutional buildings these days. This has a huge loss impact for the company and can even cost many lives. The fire occurred due to inappropriate procedures in fire safety installations and the unavailability of competent people in using fire extinguishers.

Fire fighting or better known as fire fighting is one of the important components that must be present in every building's mechanical system. Considering the magnitude of the losses caused by the fire disaster and the limited ability of fire prevention and control equipment owned by the regional fire department, plus the limited ability and knowledge of the occupants of the building regarding fire prevention measures, every building must have an automatic extinguishing system that must be used. always ready to work in case of fire.

With the condition of a good fire extinguisher, it can ensure the safety of the occupants of the building in the event of a fire. One of the most important components of this fire suppression system is the fire pump, sprinkler and piping plan.

With this automatic extinguishing system, it is hoped that fire disaster management can be carried out quickly and efficiently so that losses and casualties caused can be minimized, and by knowing more about the fire fighting work system, it is hoped that we can increase our knowledge and abilities so that it can be useful in the future.

Definition of Fire

Under certain conditions, fire is a human friend who can lighten our load, often used for cooking, heating water, warming rooms, carrying out machining processes, metal smelting and others. Behind it all, fire is an energy that can be dangerous if it is not controlled and monitored, and if a fire that arises or occurs is beyond the plan or will of humans, it can be referred to as a fire.

The Basic Theory of the Origin of Fire

Fire is a chemical reaction (oxidation reaction) which is exothermic followed by evaluation of the release of light and heat and can produce flames, smoke and coals. To start a fire process, 3 (three) elements are needed, namely materials/objects, oxygen and a heat source. When the three elements are in a concentration that meets the requirements, an oxidation reaction occurs which is known as a fire process. The presence of these three elements (in balanced concentrations), causes chemical reactions as the combustion process causes the initial fire to occur. Some of the heat will be absorbed by the material which then releases steam and gas that can be ignited alternately mixed with oxygen in the air. This state of flame will continue as long as the three elements are in a balanced concentration.

When the temperature state has reached the flash point of a material, the three elements will produce fire, which are combined to form a triangle known as the Fire Triangle of Combustion.

Once the combustion process begins and fuel and oxygen are available in large quantities, the heat generated will be even greater. With the addition will increase the amount of fuel and also the need for oxygen. Furthermore, due to the presence of oxygen, the heat of combustion is further increased and involves more fuel.

Furthermore, when the temperature reaches the flash point, the combustion process will occur again, and so on, the reaction will continue until all the fuel is used up, so that the fuel temperature decreases below its flash point and the combustion process gradually stops.

Fire Composition Components

- Heat / fire source

- Oxygen

- Fuel

Fire Fighting Principle

Basically the purpose of fire safety measures is as follows:
- Protection against life safety threats
- Protection of property including buildings
- Protection of information / ongoing processes

- Environmental protection against damage
- Minimizing damage in the event of a fire

As a realization of these actions, the fire safety system includes at least:
- Prevents ignition of fire
- Create a rescue procedure
- Limiting the spread of fire
- Detect and carry out early extinguishing

The security system needs to be realized in the design, implementation, utilization and maintenance of the system with good management.

Schematic of Fire Fighting System Components

Extinguishing Method

• Smoothering (closing/covering)
• Cooling
• Starvation (reduce/remove the amount of burning materials)
• Emulsification (clumping)

Fire Hazard Classification

- Minor fire hazard
- Medium fire hazard
- Serious fire hazard

Extinguishing System Components

- Fire pump (For this fire pump itself is divided into 2 types, namely electric pump & diesel pump)
- Jockey pump

- Pillar Hydrant

- Indoor hydrant box

- Fire alarm system (pressure switch, manometer, time delay relay, safety valve, pressure reducing valve, sprinkler)

Design

1. Planning of underground water tanks/ground water tanks

The water is taken from PDAM or deep wells. The capacity of the ground water tank is determined by the largest discharge required for the existing fire fighting system in the building and the waiting time for the arrival of the fire brigade. Waiting time is 60 minutes. The formula used is as follows:

V = Q x t

Des : V : Required volume of storage tank (m3)

         Q : water capacity (m3/h)

          t  : System operating time (60 minutes)

2. Sprinkler Flow Capacity

Q = K x √ P

Des : Q : Flow capacity of each sprinkler head (m3/h)

         K : K factor (specifications of each type of sprinkler head)

         P : Pressure (bar)

3. Pump Total Head

H = ha + Dhp + hl + (v2/2g)

Des : H      : Pump total head (m)

         ha     : Tptal head ststis (m)

         Dhp  : The difference in the pressure head acting on the two water surfaces (m)

         hl      : Various head losses in pipes, valves, turns, joints, etc.

        v2/2g : Head out speed (m)

4. Head Loss

hf = γ (L/D) (v2/2g)

Des: hf  : Friction loss head on pipe (m)

         γ   : Friction loss coefficient

        L    : Long pipe (m)

        D    : Pipe inner diameter (m)

        v     : Average flow velocity in the pipe (m/s)

        g     : Gravitational acceleration (9.8 m/s²)

5. Fluid Power

Pw = 0.163 x γ x Q x H

Des: Pw : Water power (kW)

          γ   : Coefficient of friction loss/weight of water per unit volume (kgf/l)

          Q  : Pump flow capacity (m3/s)

          H  : Pump total head (m)

6. Shaft Power

Pp = Pw/ƞp

Des: Pp   : Pump shaft power (kW)

         Pw  : Water power (kW)

         ƞp   : Pump efficiency (%)

7. Pump Motor Power

Pm = 1.1 x Pp / ƞ

Des : Pm  : Pump power (W)

         Ρp   : Pump shaft power (kW)

         1,1  : Shaft power working coefficient

         ƞ     : Pump efficiency (%)

8. NPSH

Hsv = (Pa/y) - (Pv/y) - Hs - Hls

Des : hsv : Available NPSH (m)

         Pa  : Atmospheric pressure (kgf/m²)

         Pv  : Saturated vapor pressure (kgf/m²)

         y    : Weight of liquid / unit volume (kgf/m²)

         Hs  : Static suction head (m)

So a few basics of knowledge & calculations in planning a fire fighting system. May be useful.