Installing Gas Piping
The principal recommendations to be followed when installing gas piping are:
1. A single gas line must be provided from the main gas supply to the furnace.
2. The gas supply pipe must be sized according to the volume of gas used and the allowable pressure drop.
3. The supply riser and drop leg must be installed adjacent to the furnace on either side. Never install it in front of the furnace, where it might block access to the unit.
4. A manual main shutoff valve or plug cock should be installed on the gas supply piping (usually on the riser) outside the unit in accordance with local codes and regulations.
5. Install a tee for the drop leg in the pipe at the same level as the gas supply (inlet) connection on the furnace.
6. Extend the drip leg and cap it.
7. Install a ground union joint between the tee and the furnace controls.
8. Use a pipe compound resistant to LP gas on all threaded pipe connections in an LP gas installation.
9. Test for pressure and leaks. Use a solution of soap or deter- gent and water to detect any leaks. Never check for leaks with a flame.