India is one of the huge markets comprising of many manufacturers, exporters and suppliers of pressure cap and expansion reservoir . These vendors of pressure cap and expansion reservoir are scattered all over indian markets nurturing the requirements of large variety of buyers for pressure cap and expansion reservoir who are also scattered throughout india. Different varieties of pressure cap and expansion reservoir are available for different industrial purpose. The prime importance for the buyer is to source the quality pressure cap and expansion reservoir , which also suits his requirement and pocket/budget thus increasing his production & profits.
Liquids expand when heated, just like solids do. Now when the water coolant mixture heats up, it expands pressure might build up. How does the engine manage to keep it that way? how come the liquid doesn't come bursting out? what keeps this liquid flow regulated? read to find out
The radiator has liquids within it that are extremely hot and under pressure. Also, liquid expands when heated which is considered as a part of the radiator design. However, everything built into the cooling system must accommodate for these little physical characteristics. The radiator filler neck (the mouth of the header tank) is covered with a pressure cap, which forms an air-tight joint due to which the coolant is maintained at some pressure higher than the atmospheric. Due to which the boiling point of the liquid is considerably increased which renders a few advantages already discussed later within the article.
A pressure cap contains a pressure valve and a vacuum valve. If in severe operating conditions, the coolant starts to boil or to vaporize, the pressure in the system builds up and exceeds a certain pre-determined value , the pressure blow-off value -- which operates against a pre-tensioned spring -- opens releasing the excess pressure to the atmosphere through the over flow pipe.
In some engines, however, an expansion reservoir is provided instead of an overflow pipe. This reservoir is so connected to the radiator that it receives the excess coolant as the engine temperature increases. When the liquid cools down, its volume decreases and the coolant in the reservoir returns to the reservoir to keep the coolant level in the cooling system optimal. This system is also known as coolant recovery system and it helps to prevent loss of coolant, doesn't allow air to come into the system and allows for a smaller tank.