Specifications

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10.6 STORAGE WATER HEATERS (GEYSERS)
These type of water heaters heat and store water in a tank so that hot water available to the
service point (e.g., home) at ay time. As hot water is drawn form the top of the tank, cold water
enters the bottom of the tank and is heated.
The Storage water heaters are further classified into two types.
i) Non-pressure type andii) Pressure type
Non-pressure type: When hot water is required only at one service point, this type is used. It
holds water of low pressure and hence is called as Non-pressure type. Normally it is used in
home as the pressure of the residential water system is low, which is typically 50 to 100 pounds
per square inch (psi).
Construction: The constructional parts of this type of heater are shown in Fig. 10.5 and 10.6.
i) Heavy inner steel tank that holds the hot water. Typically this tank holds 40 to 60
gallons of water. The steel tank normally has a bonded glass liner to keep rust out of the
water. The inner tank will be surrounded by lead outer tank. The space between the
tanks is filled with glass wool which prevents heat transfer from inner tank to outer tank.
This helps us to maintain the temperature of hot water for long duration.
Fig. 10.5 - Full view of storage water heater
(Non-pressure type)
ii) A dip tube to let cold water into the tank. A dip tube is provided with shutoff value to
control water in.
iii) A outlet pipe to let the hot water out of the tank
iv) A thermostat to control the temperature of the water the tank.
v) Heating element to heat the water
Fig. 10.6 - Simple view of storage water
heater (Non-pressure type)