An initially deflated and flat balloon is connected by a valve to a 12 m3 storage tank containing helium gas at 2 MPa and ambient temperature, 20 61616 C The valve is opened and the balloon is inflated at constant pressure, Po 100 kPa, equal to ambient pressure, until it becomes spherical at D1 615...

At the end of the process we have D 4 m so we can get the constant C as P 400 P C 1 100 ...

An initially deflated and flat balloon is connected by a valve to a 12 m3 storage tank

Question:

An initially deflated and flat balloon is connected by a valve to a 12 m3 storage tank containing helium gas at 2 MPa and ambient temperature, 20C. The valve is opened and the balloon is inflated at constant pressure, Po = 100 kPa, equal to ambient pressure, until it becomes spherical at D1 1 m. If the balloon is larger than this, the balloon material is stretched giving a pressure inside as

P = Po +C D D

The balloon is inflated to a final diameter of 4 m, at which point the pressure inside is 400 kPa. The temperature remains constant at 20C. What is the maximum pressure inside the balloon at any time during this inflation process? What is the pressure inside the helium storage tank at this time?