For how long Oxygen cylinder can give oxygen?

Effective use of oxygen cylinders depends upon the understanding of its working principle.
Oxygen is stored as compressed gas inside these cylinders at a pressure of about 2000psi .
(Psi=pound per square inch)
These high pressure oxygen cylinders are than used to provide oxygen to needy people in home and hospitals.
Pressure regulator are used to determine the amount of pressure remaining in the cylinders and to decrease the high pressure to low pressure.
The low pressure of oxygen is passed through flow meter to the patients.
It is very important to know for how long /for how many hours an oxygen cylinder will last so that a new cylinder can be arranged in time .
Duration of the oxygen supply depends upon three things
1. oxygen capacity of the cylinder,
2. Pressure left in the cylinder
3. Oxygen flow rate at which we give oxygen
The mathematical formulae for
As per Boyles law:
P1V1=P2V2
Here,
P1=initial pressure
V1=initial volume
P2=remaining pressure
V2=remaining volume
where P and V refer to pressure and volume, respectively. Substituting the product of flow rate, Q, and remaining time, t, for Vi yields:equation
P1 x Qt=P2 x V2
t ( in mins)=P2 x V2
-----
P1 x Q( flow /min)
t ( in hrs) = P2 x v2
-----
2000 x flow/min x 60
This formula uses typical units for pressure of pounds per square inch, volume in liters, and flow rate in liters per minute. The 60 in the denominator converts minutes into hours. It should be noted that Vr is the volume of the E-cylinder. The usual values for Pi and Vr are 1900 PSI and 660 L, respectively.
The approximate formula is based on rounding Vr down to 600 L and using a value of 2000 PSI for Pi. This also creates a “margin of safety” for the estimated remaining time:equation
t ( in hrs ) = P2 x 600
-----. [for E type ]
2000 x 60 x flow
Therefore,
H type cylinder is :
Capacity=6900 liters ~6000 liters
Pressure when full=2000psi
Time (in hrs) = remaining pressure
----------- [ for H type ]
20 x flow rate
For E TYPE CYLINDER
Time ( in hrs ) = remaining pressure
-----------[ for E type]
200 x flow rate
#oxygen #oxygencylinder