Question

You are advised not to open the radiator cap of the radiator of your car(pressure cap) when it is very hot. The reason is that the pressure inside radiator is more than outside atmospheric pressure and hot water will gush out if the cap is opened. Explain why radiators are designed to work under such higher pressure. That is, What is the benefit gained?

Answer 1

We are advised not to open the radiator cap of our car (pressure cap) when it is very hot. The reason is that the pressure inside radiator is more than outside atmospheric pressure and hot water will gush out if the cap is opened.

Explain why radiators are designed to work under such higher pressure.

The purpose of the radiator is to cool down the water received from the engine. The radiator consists of three main parts like upper tank, lower tank & tubes. In the case of an ordinary water-cooling system where the cooling water is subjected to atmospheric pressure, the water boils at 212 ⁰F. But when water is boiled in a closed radiator under high pressure, the boiling temperature of water increases. The higher water temperature gives more efficient engine performance and affords additional protection under high altitude and tropical conditions for long hard driving periods.

Any increase in pressure is released by the pressure release valve to the atmosphere. However, pressurized systems were also more complex and far more susceptible to damage as the cooling fluid was under pressure.