Gas installation design should be made based on Renouard formulas simplified to medium and low pressure.the losses of maximum allowable pressure are:
- Medium Pressure: 30 mbar.

- Low Pressure: 2.0 mbar.

the maximum admissible speeds are as follows:
- Average pressure: 15 m / s.

- Low pressure: 10 m / s.

The maximum instantaneous flow rate is normally calculated taking the sum of the flow rates of the most potent and apparatus semissoma the other.

The line pressure drop and the influence of the gap in pressure is calculated according to Formula Renouard to low pressure.