Using a flexible gas line to connect a cooktop to a gas supply line is common practice. Flexible gas lines provide a safe, convenient way to hook up gas appliances like cooktops in a kitchen. However, there are some important considerations when selecting and installing a flexible gas connector for your cooktop.
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What is a Flexible Gas Line?
A flexible gas line, also called a gas appliance connector, is a stainless steel or brass corrugated tube used to connect a gas appliance to a gas supply line. Flexible gas lines are typically 2 feet long and have female threaded fittings on both ends to connect to the appliance and supply line. The convoluted design allows flexibility for positioning the appliance.
Flexible gas lines are used for the final connection between the rigid gas supply line and appliances like cooktops, ovens, dryers, fireplaces, and more. Using a flexible gas line allows some wiggle room in placing the appliance and avoids putting stress on the fittings from movement.
Benefits of Using a Flexible Gas Line for a Cooktop
There are several benefits to using a flexible gas line to hook up a cooktop rather than a rigid pipe connection:
- Versatile installation – Flexible gas lines allow for easier installation in tight or awkward spaces. The line can bend to fit around obstructions.
- Absorbs vibration – The flexible corrugated design absorbs vibration from the cooktop to reduce strain on the fittings.
- Simplified positioning – A flexible gas line accommodates repositioning the cooktop for cleaning or maintenance.
- Reduced stress on fittings – Flexible lines prevent stress on the fittings from cooktop movement during use.
- Quick connection – Flexible gas lines allow cooktops to be installed, removed, and reconnected quickly.
- Professional look – Flexible gas lines give a tidy, professional look compared to exposed rigid pipe.
The flexibility and convenience of using a flexible gas line makes connecting a cooktop much simpler compared to inflexible pipe. As long as the flexible line is sized properly and installed correctly, it can provide a safe and secure gas connection.
Sizing a Flexible Gas Line
Choosing the right size flexible gas line is important for proper cooktop operation. Flexible gas lines are measured by their inside diameter, typically 1⁄2 inch or 3⁄4 inch.
The steps for sizing a flexible gas line are:
- Determine the BTU rating for the cooktop – This can usually be found on the model’s rating plate.
- Identify the gas supply line type coming out of the wall – This is typically 1⁄2 inch pipe for residential.
- Calculate the total BTU load – Add up the BTUs if connecting multiple appliances on the same line.
- Consult a sizing chart – Match the BTU rating to the proper line diameter.
As an example, for a cooktop with a 36,000 BTU rating connected to a 1⁄2 inch supply line, a 1⁄2 inch flexible gas line would be appropriate. If combining with a kitchen oven, a larger diameter may be needed to handle the total BTU load.
Flexible Gas Line Sizing Charts
Sizing charts are available in manufacturer specifications and building codes to choose the right flexible gas line size based on the BTU rating and pipe size. Here is a typical sizing chart for reference:
| Pipe Size | Max BTU for 1/2″ Flexible Line | Max BTU for 3/4″ Flexible Line |
|---|---|---|
| 1/2″ Pipe | 72,000 BTU | 192,000 BTU |
| 3/4″ Pipe | 192,000 BTU | 350,000 BTU |
This chart shows the maximum BTUs a 1⁄2 inch or 3⁄4 inch flexible gas line can support from a 1⁄2 inch or 3⁄4 inch supply line. Always follow manufacturer specifications and building codes for sizing requirements.
How to Install a Flexible Gas Line
When installing a flexible gas line for your cooktop, follow these steps:
- Turn off the gas supply – Shut off the main gas supply valve before beginning.
- Check for leaks – Test the gas supply line for leaks with a leak detector prior to installation.
- Measure the needed length – Determine the length of flexible gas line required between the gas supply line and cooktop.
- Cut the flexible gas line – If needed, cut the flexible gas line to the desired length using a tube cutter.
- Flare the end – Flare out the end of the flexible line using a flaring tool if connecting to a flare fitting.
- Connect the flexible line – Attach the flexible gas line securely to the gas supply at one end and the cooktop at the other.
- Position the cooktop – Carefully position the cooktop, leaving room for movement.
- Perform leak tests – Test all connections for leaks by brushing on leak detector solution.
- Turn on gas and test operation – When no leaks are found, slowly turn on the gas supply and test cooktop operation.
The flexible gas line should be installed in a gentle arc without kinks or tension. It’s important to perform thorough leak checks at all connection points before use.
Flexible Gas Line Safety Tips
To ensure safe installation and operation with a flexible gas line for your cooktop, keep these safety tips in mind:
- Carefully read manufacturer instructions for installation guidelines.
- Only use approved flexible gas lines that comply with standards like ANSI Z21.24/CSA 6.10.
- Avoid running the flexible gas line through walls, floors, or ceiling openings.
- Do not use a flexible gas line longer than absolutely necessary.
- Protect the flexible gas line from punctures, kinks, and abrasion damage.
- Perform leak tests with every new connection and regularly thereafter.
- Never repair or modify a flexible gas line yourself.
- Replace old or damaged flexible gas lines immediately.
Can You Use an Old Flexible Gas Line?
Old flexible gas lines that are damaged or do not comply with current standards should not be reused. Signs that a flexible gas line needs replacement include:
- Damage such as cracks, dents, cuts, or abrasions in the line
- Corrosion on fittings or piping
- Leaking connections
- Kinks or restrictions in the line
- Older styles that used rubber hose instead of stainless steel
- Installation date over 10-15 years ago
Flexible gas lines can become cracked or deteriorated over time, posing safety risks. Always replace an old flexible gas connector when installing a new cooktop rather than reusing it.
Flexible Gas Line Code Requirements
There are various code requirements surrounding the use of flexible gas lines that must be complied with. These include:
- ANSI Z21.24/CSA 6.10 – Covers standards for connectors used with gas appliances.
- NFPA 54/ANSI Z223.1 – National Fuel Gas Code for gas line sizing and installation.
- Local building codes – May have additional provisions for flexible gas line usage.
The flexible gas line must be UL/CSA approved and installed per manufacturer specifications, NFPA codes, and local building codes. Usage over 3 feet and concealed installation may be prohibited. Only qualified professionals should install gas appliances and connectors.
Code Requirements for Cooktop Flex Connectors
Specific NFPA 54 code requirements for flexible gas line connections to cooktops include:
- Maximum 3 foot length, minimum 1 foot length.
- Must be installed in the same room as the cooktop with no concealment.
- Must not pass through walls, floors, ceilings or appliance panels.
- Must be protected from physical damage if installed below the cooktop.
- Shutoff valve must be installed within 6 feet of the cooktop.
The flexible gas line for a cooktop connection should be visible, accessible, and installed only per manufacturer instructions to comply with code.
Flexible Gas Line vs. Rigid Gas Pipe
| Flexible Gas Line | Rigid Gas Pipe | |
|---|---|---|
| Installation | Easier to install in tight spaces | More difficult, requires precise cuts |
| Flexibility | Can bend around obstructions | Must be installed in fixed straight lines |
| Appearance | Provides a tidy, hidden connection | Exposes pipework |
| Convenience | Allows repositioning of appliances | Appliance position is fixed |
| Safety | Risk of leaks, damage over time | Less prone to disconnection or leaks |
| Cost | More affordable | Higher material and labor costs |
In summary, flexible gas lines provide simplicity and flexibility compared to rigid piping, but require care to ensure safe operation. Rigid gas pipe offers robustness but lacks convenience. Following safety procedures is critical with any gas cooktop installation.
Conclusion
Using a flexible gas line is an approved method for connecting a cooktop safely and conveniently. When properly sized and installed, a flexible gas connector provides a durable, leak-free supply of gas to the cooktop while allowing flexibility in placement.
The flexible gas line must comply with codes for length, concealment, and installation method. Regular inspections and leak testing are required to catch any wear and tear over time. With careful installation and maintenance, a flexible gas line provides a reliable gas connection to your cooktop.