A leak somewhere in the system.
50
Most standard domestic plumbing systems in north America will hold 125 psi, however most operate at anywhere from 35 -85 in daily use.
There is an air fitting on the tank, where you can check the pressure on the one side of the diaphragm. Hold you hand over it and see if the air is leaking out here. If air is leaking out here, you need to get a tire valve tool and tighten the pin. If the diaphragm was bad, the tank would completely fill with water and this should not cause that sound. There is a pressure switch, and the plumbing lines, but if there where to whistle, you would see water leaking out.
With no air in the system anywhere, there would be nothing to hold pressure, so the slightest leak would cause the system to go to zero.
The fuel pressure regulator is bad, one or more fuel injectors is leaking or the check valve in the fuel pump is faulty.
The amount of air pressure a balloon can hold depends on its material and size. Latex balloons can typically hold around 10-15 pounds per square inch (psi) of pressure, while Mylar balloons can hold higher pressures of up to 25 psi. Overinflating a balloon beyond its capacity can cause it to burst.
Because there is no air and thus no pressure that would hold your atoms together
Sounds like you have a bad seal on the rack and pinion. The bellows is only to keep dirt and water out of the rack and pinion, it is not a seal to hold pressure in.
If the pressure cap on the surge tank is left loose, defective or will not hold pressure.
I would tell you but I can not
I'm not entirely convinced you'd be allowed to but... If it's in the cabin, nothing - as the cabin is pressurinsed to ground level. In the cargo hold it would eventually explode, as the cargo hold (unless in the pressurised area for animals) is not pressurised. Therefore the air pressure inside the rugby ball would eventually cause it to burst.
Too much pressure for size and type of wall. What's it made of and how much is it trying to hold back?