Determining the right size gas line for a gas stove is an important consideration when installing or replacing a gas range. The gas line size impacts the stove’s performance and safety. Selecting pipe that is too small can result in insufficient gas flow, leading to issues like slow heating times, low flames, or activation of safety valves shutting off the gas supply. On the other hand, oversized gas lines are wasteful and unnecessary. This article provides a detailed guide on how to determine the proper gas line size for residential stoves based on gas type, input BTU rating, and distance from the supply regulator.
Page Contents
Factors That Determine Gas Line Size
There are three key factors that determine what size gas supply line is required for a stove:
- Gas Type – Natural gas requires a smaller pipe size than propane for an equivalent BTU appliance. This is because natural gas flows faster than propane.
- BTU Rating – The max BTU/hr rating on the stove determines the required volumetric gas flow. Higher BTUs need bigger pipes.
- Distance To Regulator – More pipe length means more friction loss, so longer distances need larger lines.
These parameters are used with gas pipe sizing charts to calculate the proper diameter. Rules for minimum sizes also apply. We’ll now look at how to determine the specifics for your stove installation.
Gas Stove BTU Ratings
The key gas volume requirement for stove lines is the BTU per hour rating. BTU stands for British Thermal Unit, which is a standard measure of heat energy. Appliance specifications will list the maximum BTU/hr consumption for each gas burner. Here are some typical values:
| Stove Burner | Typical Max BTU/hr |
|---|---|
| Small Burner | 5,000 |
| Medium Burner | 10,000 |
| Large Burner | 15,000 |
| Extra-Large Burner | 20,000 |
For example, a stove with (2) 15,000 BTU burners and (2) 10,000 BTU burners would have a total max BTU/hr rating of 50,000.
Gas Line Sizing By Gas Type
Natural gas and propane have different densities and flow characteristics. As a result, separate pipe sizing guidelines apply for each:
Natural Gas Line Sizing
For natural gas stove lines, you can use the capacities in the following table to determine the minimum pipe diameter based on length and max BTU demand:
| Pipe Size (in) | Length (ft) | Capacity (BTU/hr) |
|---|---|---|
| 1/2 | 10 | 132,000 |
| 1/2 | 20 | 92,000 |
| 1/2 | 30 | 73,000 |
| 1/2 | 40 | 63,000 |
| 1/2 | 50 | 56,000 |
| 3/4 | 10 | 278,000 |
| 3/4 | 20 | 190,000 |
| 3/4 | 30 | 152,000 |
| 3/4 | 40 | 130,000 |
| 3/4 | 50 | 115,000 |
| 1 | 10 | 520,000 |
| 1 | 20 | 350,000 |
| 1 | 30 | 285,000 |
| 1 | 40 | 245,000 |
| 1 | 50 | 215,000 |
For example, if you need to run a 20 foot natural gas line to a range with a max BTU of 65,000, a 1/2″ pipe would be adequately sized.
Propane Gas Line Sizing
For propane stove lines, you can use this capacity table:
| Pipe Size (in) | Length (ft) | Capacity (BTU/hr) |
|---|---|---|
| 1/2 | 10 | 291,000 |
| 1/2 | 20 | 200,000 |
| 1/2 | 30 | 160,000 |
| 1/2 | 40 | 137,000 |
| 1/2 | 50 | 122,000 |
| 3/4 | 10 | 608,000 |
| 3/4 | 20 | 416,000 |
| 3/4 | 30 | 333,000 |
| 3/4 | 40 | 284,000 |
| 3/4 | 50 | 252,000 |
| 1 | 10 | 1,150,000 |
| 1 | 20 | 792,000 |
| 1 | 30 | 632,000 |
| 1 | 40 | 541,000 |
| 1 | 50 | 480,000 |
As an example, for a 50 foot run to a propane stove requiring 180,000 BTU, a 3/4″ line would be sufficient.
Minimum Gas Line Sizes
Even if the BTU load calculations show a smaller pipe will work, there are rules for minimum gas line sizes that must be followed:
- Minimum 1/2″ diameter for any individual appliance branch line (final stub out).
- Minimum 3/4″ diameter for a natural gas appliance supplying up to 200,000 BTU total.
- Minimum 1/2″ diameter for a propane appliance supplying up to 150,000 BTU total.
So for instance, you would not want to use 1/2″ pipe for a range with 250,000 BTU rating, even if the length was short. A 3/4″ or 1″ line would be safer and meet code.
Total Home Demand Considerations
When sizing the main gas trunk line coming into the home, you need to consider the total gas demand for all appliances, not just the stove. This includes:
- Water heater input rating
- Furnace/boiler input rating
- Any other gas appliances (fireplace, grill, etc.)
Calculate the total max BTU/hr demand and size the main line accordingly using the capacity tables. A licensed plumber can perform this sizing calculation for you.
Gas Pipe Materials
The material the gas pipe is made out of also factors into line sizing:
- Black Iron Pipe: Standard material, lined for natural gas. Sizing tables are based on black iron pipe capacities.
- CSST Tubing: Corrugated stainless steel tubing. Has higher flow for a given diameter compared to iron pipe. Must follow size reduction rules.
- Copper Pipe: Hard copper tubing avoids corrosion issues but has lower flow capacity. Generally needs one size larger lines.
When using anything other than standard black iron pipe, be sure to consult sizing guidelines for that specific tubing material.
Conclusion
Choosing the proper gas line size for a gas range involves matching the BTU demand to pipe capacities based on length and type of fuel. Always follow minimum size rules. Consider the total connected load for an entire house when sizing the main feed line from the meter. Consult local codes for specifics. Hiring a qualified technician to install and inspect gas piping is highly recommended.