because horizontal vessels can't kept a high presssure
At low temperature and high pressure, the VOLUME of the gas will be reduced.
I think a vessel is containing a fluid under high pressure whereas a drum contain a fluid with no or low pressure.
Pulmonary arterial system has high pressure but low oxygen concentration.
A high pressure system has a weaker horizontal pressure gradient than a low pressure system, which means the atmospheric pressure varies widely in a low pressure system and doesn't vary much in a high pressure system. The wind speed depends on the strength of the horizontal pressure gradient.On a meteorological map, the horizontal pressure gradient is marked with isobars, which are lines with match the points with the same atmospheric pressure. A high pressure system is characterized by widely spaced isobars while low pressure systems are noted by tightened close isobars.A high pressure system may have an air pressure of 1028 hPa in his core and 1013 hPa in its periphery: the air pressure varies about 16 hPa. A low pressure system may have an air pressure of 987 hPa in its core and 1013 in its periphery : the air pressure varies about 26 hPa. So, the winds will be very light and even non-existent in a high pressure system while the winds will be very strong and even turbulent in a low pressure system.
So that it does not collide with the walls
Wind occurs because air tends to move from region of higher to lower pressure.
Add refrigerant vapor on the low side of the system ,the compressor raises the pressure of the refrigerant on the high side of the system and lowers the pressure on the low side
Add refrigerant vapor on the low side of the system ,the compressor raises the pressure of the refrigerant on the high side of the system and lowers the pressure on the low side
Add refrigerant vapor on the low side of the system ,the compressor raises the pressure of the refrigerant on the high side of the system and lowers the pressure on the low side
There is nothing that is specifically designed to keep the air pressure low under a train. A train is kept on the tracks by gravity, nothing more.
The effect is called horizontal convergence.
to store water where the there is a need for it ie a site of low water pressure so when there is high demand the pressure can be kept