Gas Supply & Pressure Fundamentals
Natural gas and propane supply pressures, manifold pressures, regulator operation, lock-up testing, and pressure regulation.
- State standard supply and manifold pressures for natural gas and propane
- Explain regulator operation and lock-up testing
- Differentiate natural gas and propane properties
Leçon 1
Natural Gas Supply Pressures
Standard Pressures
Natural gas is delivered to residential and small commercial buildings at regulated supply pressure. The gas utility delivers gas at a higher pressure to the meter, and a service regulator at or near the meter reduces it to the standard supply pressure.
Pressure Measurement
Gas pressure is measured in inches of water column (WC) using a manometer or digital pressure gauge. One inch WC equals approximately 0.036 psi - a very low pressure compared to other utility systems.
The standard supply pressure at the outlet of the service regulator is 7 inches WC for natural gas in most Canadian jurisdictions. The manifold pressure (at the appliance gas valve) is typically 3.5 inches WC for natural gas appliances.
Key Exam Numbers
Memorize these pressures: Natural gas supply = 7" WC, natural gas manifold = 3.5" WC. These are the most frequently tested pressure values on the G2 exam.
Natural gas standard supply pressure is 7 inches WC. Standard manifold pressure is 3.5 inches WC. Pressure is measured in inches of water column using a manometer.