A commercial kitchen appliance on casters needs a gas connector listed to ANSI Z21.69/CSA 6.16, sized for its full Btu load, no longer than 6 feet, with its own shutoff valve ahead of it. The fuel gas code also requires a restraint cable, shorter than the hose, so moving the appliance can't pull on the gas line.
What makes a commercial gas hose different?
A Z21.69 connector is made and tested for appliances that get pushed and pulled for cleaning. Dormont's instructions for its commercial connectors spell out the rules that come with one:
- Low pressure only. "Connectors are for use only on piping systems having fuel gas pressure not in excess of 1/2 psi." In a building with 2 psi gas, a regulator has to drop the pressure before the hose.
- One appliance, one location. "DO NOT REUSE FOR ANOTHER APPLIANCE OR AT ANOTHER LOCATION." Dormont's FAQ adds that once equipment is taken out of service, CSA gas connector rules "do not allow the reuse of gas connectors."
- No kinks or twists. The connector "shall not be kinked, twisted, or torqued when installed," and it has to stay clear of surfaces hotter than 230°F, sharp edges and wiring.
- Keep strong cleaners off it. Acids, solvents and chlorinated chemicals must not touch the connector. Rinse and dry it if they do.
What does the fuel gas code require at the connection?
Section 411.1.3 sets the limits for every appliance connector, and restaurants run into all of them:
| Code rule | What it says |
|---|---|
| Length | "Connectors shall have an overall length not to exceed 6 feet" |
| Count | "Only one connector shall be used for each appliance" |
| Capacity | Connectors "shall have the capacity for the total demand of the connected appliance" |
| Location | Not concealed in, or run through, walls, floors, partitions, ceilings or appliance housings |
| Shutoff | A valve "not less than the nominal size of the connector" ahead of it |
Section 409.5.1 puts that shutoff valve in the same room, within 6 feet of the appliance, and upstream of the connector and any quick-disconnect. A valve behind movable cooking equipment counts as accessible. Dormont adds that "Each piece of equipment must have its own shut-off valve," and that the quick-disconnect coupling is not to be used as the primary gas shutoff.
Size matters more than people think. Dormont's capacity table shows a 1/2 inch connector at 6 feet rated for 86,600 Btu per hour straight, dropping to 55,000 with a quick-disconnect. A 3/4 inch connector with a quick-disconnect at 6 feet carries 139,000. Put a big fryer on a small hose and it runs short of gas at the worst time. Our guide to whether a restaurant gas line can handle a new fryer covers the rest of that math.
What is the restraint cable, and how is it set up?
The restraint is a short steel cable between the wall and the back of the appliance. Its only job is to stop the appliance before the gas hose goes tight. Dormont's FAQ describes it as a cable that "connects the moveable gas appliance to the wall" and is "designed to be shorter than the gas connector used on the same piece of equipment."
Dormont's installation steps for its restraining device:
- 1Mount the wall bracket to a stud, in line with the gas connector.
- 2Attach the eye-bolt to a structural part of the appliance frame, not a thin panel.
- 3Clip the cable to both points with the snap hooks.
- 4Set the length so the connector isn't kinked when the cable is fully extended.
The rule that matters most is simple: "Restraining cable MUST BE connected at all times when appliance is in use." Dormont also says the restrainer "should be inspected as part of the regular maintenance and safety procedures."
### What does a good installation look like?
Most of it comes down to geometry. Dormont's installation booklet recommends putting the gas supply manifold 30 to 42 inches off the floor, with the pipe tees pointed down, so the hose hangs in a natural loop instead of bending hard at its fittings. Its instructions and diagrams stress a few more points:
- No sharp bends at the end fittings. Where the layout would force one, Dormont points installers to swivel-style connector assemblies.
- The quick-disconnect faces the right way. Gas "enters the coupling half and exits the nipple half," following the flow arrows marked on it. Never push a screwdriver or probe into the coupling, which can damage the valve seat.
- No quick-disconnect on dual-fed lineups. When a lineup of equipment has dual front manifold gas inlets, Dormont says not to use a quick-disconnect coupling.
- A leak test on the finished assembly, with leak-detecting solution, never a flame. The instructions note that test solutions can corrode, so rinse with water afterward.
A hose that lies on the floor where the appliance can roll over it, or that's stretched tight when the equipment sits in its normal spot, is set up wrong. Fix it before it fails.
How should staff move equipment for cleaning?
In a set order, every time, so the hose never takes the pull. Dormont's routine for cleaning behind equipment:
- 1Turn off the appliance.
- 2Pull it out gently until the restraint cable is taut. Stop there.
- 3Close the appliance's gas shutoff valve.
- 4Disconnect the quick-disconnect coupling. Don't drop it on the floor.
- 5Unclip the restraint cable, then roll the appliance out and clean. Keep grease, water and cleaner out of the coupling.
- 6To put it back: reattach the restraint cable first, then reconnect the quick-disconnect, open the gas valve, and roll the appliance in without crushing or kinking the hose. Dormont's restraint instructions say to "Reconnect restraining cable before reconnecting the gas connector."
Relight any pilots per the appliance instructions. If you smell gas at any point, don't touch switches, thermostats or appliance controls. Get everyone out, then call 911 and Southwest Gas at 877-860-6020 from a safe place.
Who owns the hose, and does a swap need a permit?
The hose is yours. Southwest Gas's Arizona tariff defines the customer's piping system as everything from the meter outlet to the appliance shutoff valves, and says the term "excludes appliance connectors and appliances." The connector and the appliance are the business's own equipment beyond that.
Replacing a worn connector or swapping an appliance in kind usually doesn't trigger a permit. Phoenix's gas clearance table, published with Southwest Gas and the Arizona Corporation Commission, exempts "the installation of an appliance connector" from the alteration row and lists "Replacement in kind of any gas appliance with no gas piping alterations" as no permit. Moving the valve, adding an outlet or extending the manifold is piping work, and that needs a permit and inspection.
Signs a connector needs replacing now: a crushed or flattened section, a torn jacket, a stiff or kinked spot near a fitting, or any gas smell at the connection. Our page on a gas smell in a restaurant covers what to do first if you smell it.
HQ Plumbing & Air installs commercial kitchen gas lines, manifolds, shutoff valves, listed connectors and restraints for restaurants across the Phoenix area, and pressure tests the work. We're licensed and insured, with free estimates and upfront pricing.
Listed hose, its own valve, cable clipped on. Done.