Q1: A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm².

ANS:B - 18

A fire tube boiler is typically limited to a maximum steam pressure of about 18 kg/cm2. Explanation:

1. Fire Tube Boiler: In a fire tube boiler, the hot gases produced by the combustion of fuel flow through tubes immersed in water. The heat from these gases is transferred to the water, which generates steam. Fire tube boilers are commonly used for small to medium capacity applications.
2. Pressure Limitation: The design and construction of fire tube boilers impose certain limitations on the maximum steam pressure they can safely handle. These limitations are determined by factors such as the strength of the boiler materials, the design of the boiler shell, and safety considerations.
3. Typical Pressure Range: Fire tube boilers are generally suitable for operating at steam pressures up to about 18 kg/cm2 (approximately 18 bar or 260 psi). Beyond this pressure range, the design constraints of fire tube boilers may become limiting factors, and other types of boilers, such as water tube boilers, are typically employed for higher-pressure applications.
4. Safety Considerations: Operating a boiler beyond its design pressure can pose safety risks, including the potential for boiler failure, explosions, and other hazardous conditions. Therefore, it is essential to adhere to the manufacturer's specifications and industry standards when operating boilers.
5. Application Limitations: While fire tube boilers are suitable for a wide range of applications, their pressure limitations may restrict their use in high-pressure steam applications, such as power generation or industrial processes that require higher steam pressures.