Gas Line Sizes for Boilers

Boiler Needs

• The size of gas line you use for a boiler ultimately depends on the needs of your particular boiler. All gas appliances require a certain amount of gas, measured in cubic feet, delivered to the system per hour. The pipes you use for a boiler gas line must exhibit adequate diameter to transport the required amount of gas without problems. Pressure drop, or the change in pressure between two systems such as a gas line and a boiler, affects how much gas a pipe can deliver in relation to its diameter.

Building Codes

• Building codes at the national, state, county and municipal levels govern required construction processes and materials in a set area. These codes contain provisions for every aspect of building, including things like boiler gas line sizes. The Florida Building Code, for instance, contains a 150-page appendix titled “Sizing and Capacities of Gas Piping.” This appendix contains numerous charts that list required sizes of gas pipes based on pressure drop, valves, appliance type and other considerations. Always check your local building code for specifications on gas line sizing before installing pipes with your boiler.

Manufacturer Recommendations

• The manufacturer of your gas boiler should provide you with the cubic foot-per-hour fuel requirement for your boiler when you purchase it. Find this information in your boiler's manual. If you don't have a manual, contract your boiler's manufacturer or vendor to get one. In addition to information on gas requirements, your manual should contain information on the proper type and size of gas lines to use with your boiler. Before installing gas lines based on manufacturer recommendation, ensure the recommendations meet the requirements of your local building code.

Installation

• Installing gas lines technically constitutes a form of plumbing, albeit one not involving water. When it comes to choosing, purchasing and installing gas lines for your boiler, contact a local contractor, plumber or boiler specialist for assistance if you have no experience in these fields. A professional can help you find the right size pipes, locate building codes and provide advice on how best to set up your gas lines. If you insist on completing the installation yourself, this help may prove invaluable during the installation process.