I have two questions:

How to convert a 150 standard cubic feed (SCF) of Air to the Actual Cubic feed (ACF)?

How to convert a 150 standard cubic feed (SCF) of Natural Gas to the Actual Cubic feed (ACF)?

The actual Temp is 30°C and press is 100 psig

I would appreciate any input

 

This involves the gas laws - P1 x V1/T1 = P2 x V2/T2.

Using V as a prefix for Actual and B for Base this can be written to give the volume at base conditions as

VA = VB x PB/PA x TA/TB -

As pressure goes up, the volume goes down; as temperature goes up the volume goes up.

Remember that the temperature and pressure terms used must be absolute
rather than gauge. You will need to find out what the Standard conditions are - usually 1 standard atmosphere, but the temperature could be 60 °F, 15 °C, or a number of other possibilities.

It doesn't matter (to a first approximation) what the gas is.

Cheers,
Bruce.