Radiator pressure cap working explained скачать в хорошем качестве

Radiator pressure cap working explained

As you know, your engine produces a lot of heat while running. All engines are designed to work efficiently within a certain temperature range, normally 185-205° F (or 85-96° C). The cooling system is designed to keep the engine within this temperature range for maximum performance and fuel efficiency. Pressurized cooling systems are designed to do all of the following: Allow the engine to warm up to its ideal operating temperature quickly. Circulate coolant through the engine to maintain that ideal temperature. Maintain coolant level and pressure by circulating excess coolant to and from the overflow tank as the coolant heats up and cools down. The coolant in your system should be a 50/50 mix of water and antifreeze. Water is what pulls the heat out of the engine, but due to its high freezing temperature, low boiling point, and the fact that it allows corrosion to develop within the system we have to add antifreeze. Antifreeze provides a lower freezing temperature, a higher boiling temperature, and inhibitors to prevent corrosion. The water/antifreeze mixture provides us with a freezing point of -35° F (-37° C) and a boiling point of 223° F (106° C). (For more detailed information about the purpose of antifreeze check out our “Do I need Antifreeze in Warm Weather?” article.) While our coolant gives us some wiggle room for running our engine, warmer weather may prove to be an issue. This is where the “pressure” of our cooling system comes into play. When you increase the pressure on a liquid, you raise its boiling point. Our coolant’s boiling temperature of 223° F (106° C) is when it is under 1 psi, which is why most cooling systems are designed to operate at 15 or 18 psi. As the coolant heats up, it begins to expand and create additional pressure. By allowing that pressure to increase, the boiling point of the coolant is increased to around 257° F (125° C) at 15 psi. This gives us better performance from our cooling system as it can absorb additional heat from the engine without boiling. But what happens when the pressure exceeds the system’s psi rating? As you may have guessed at this point, regulating the pressure within the cooling system is the job of the pressure cap. Purpose of the Pressure Cap When the pressure inside the cooling system increases above its psi rating, the pressure cap releases some of the coolant into the overflow tank. It does this by use of a spring loaded valve. Once enough coolant has exited the system to reduce the pressure, the valve closes again. This action allows the system to remain at the optimal psi while the engine is running. This is great for when the engine is running, but what happens when you turn it off? As the engine cools down and the pressure in the system drops, the pressure cap allows the excess coolant in the overflow tank to return to the system by use of a second spring loaded valve. This second valve responds to the vacuum created in the system from the drop in pressure and pulls the coolant out of the overflow tank. Not only does this recycle the excess coolant to prevent air pockets in the radiator, but it also prevents the softer components of the cooling system, such as the hoses, from becoming crushed by the external air pressure.