At what pressure are propane and butane typically available in cylinders?

Propane and butane are commonly stored in cylinders under pressure as liquefied gases. The typical pressure at which they are available in cylinders is influenced by their physical properties and ambient temperature.

For propane, the pressure in a cylinder can range from approximately 100 psi to 200 psi, depending on the temperature. At 70 degrees Fahrenheit, propane generally exerts a pressure of around 130 psi. Butane, on the other hand, has a lower vapor pressure than propane; at similar temperatures, it commonly sits around 30-40 psi.

Given these dynamics, the specified range of 80 to 120 psi accurately represents a middle ground for these gases under various conditions, where propane predominantly contributes to the higher end due to its higher vapor pressure. This pressure range ensures that both propane and butane can be safely stored and transported in cylinders while still maintaining their intended use as energy sources.

Further, understanding the operating pressures is crucial for proper system design and safety practices in plumbing and gas supply installations. Therefore, choosing the range of 80 to 120 psi as the standard pressure for these gases reflects an appropriate understanding of their behavior in storage and handling.