One advantage is strength. Stainless steel is an extremely strong metal that, compared to brass, delivers superior performance in a wide range of standard performance tests – including greater tensile, torsion, hydrostatic and axial strength. Another advantage is corrosion resistance. Stainless steel is an excellent all-purpose metal that is resistant to a wide range of corrosive substances. It addresses concerns regarding corrosion caused by ammonia (found in common household cleaning solutions) and sulfur (sometimes present in natural gas).
The main advantage of Dormont stainless steel gas connectors is their No-Neck® Design. Dormont Safety System™ stainless steel gas connectors have an exclusive design in which the first few corrugations are protected by a flare nut. Unlike all other brands, the No-Neck Design protects the non-flexible tubing neck when there is a sharp bend at the connector end.
Brass connectors are very susceptible to corrosion by ammonia and common cleaning chemicals that contain ammonia. The corrosion may cause pinholes and cracks, which may result in hazardous gas leaks.
Brass is also susceptible to damage from work hardening due to even small amounts of vibration. Some appliances may produce enough vibration to cause failures in brass connectors over time. Because of the inherent problems with brass connectors, manufacturers are required to coat their products. While the coating helps, it can easily chip or crack, which can undermine the purpose of the coating.
While stainless steel is a strong and durable metal, Dormont’s Safety Shield® coating provides added protection against corrosive chemicals.
Safety Shield® is provided in a vibrant yellow color, which is the industry-recognized color for gas line identification.
Excess Flow Valves (EFVs) are custom-engineered fittings designed to provide added protection in the event of a complete rupture of the gas appliance hose. They have an internal valve mechanism, and under normal conditions, the valve remains opened, allowing gas to flow at normal gas line flow rates. In the event of a complete downstream gas line rupture, which causes excess gas flow, the EFV is automatically tripped (closed), greatly reducing the gas flow. This reduced flow is maintained until the upstream manual shut-off valve is closed and the gas line is repaired. After the gas line is repaired and the pressure is equalized, the EFV will automatically reset and restore normal gas flow.
Please contact your local Code Official to determine whether your locality requires appliance EFVs.
Flare fittings provide a mechanical method of attaching tubing to fittings. The flare fitting design used by gas appliance connectors is derived from the SAE J512 Standard. It provides a gas tight metal-to-metal seal by sandwiching the stainless steel tube between a flare nut and an adapter. Besides gas connectors, flare fittings are commonly used in high performance automotive, refrigeration and hydraulic applications.
In the early days of the 5/8” OD / ½” ID gas connector, the flare nut threads were approximately the same size as a ½” NPT pipe thread. There was a potential for an incorrect installation to occur when SAE flare nut threads were inadvertently attached to NPT pipe threads. This arrangement would not seal because the NPT threads do not have a flare surface to mate with the SAE flare, which provided a dangerous condition. The ANSI Technical Advisory Group (TAG) for Gas Connectors changed the design requirement for the 5/8” OD/ ½” ID (30 series) connector to require a 15/16 – 16UN thread, which cannot be accidentally mated with a ½” NPT pipe thread.
Product standards are a list of requirements a governing body creates to determine whether a manufacturer’s product will be safe when used in an installation. The requirements can include specifying the materials used to construct the product along with performance tests that the product must pass in order to be given the approval to be sold in the marketplace. Governing bodies include CSA Laboratories (formerly known as the American Gas Association or AGA), Underwriters Laboratories (UL) and The International Association of Plumbing and Mechanical Officials (IAPMO).
Installation/model building codes are rules that govern where and how gas connectors may be used in specific applications. There are several regional and national building codes, including the International Fuel Gas Code and the Uniform Plumbing Code. The codes typically refer to the applicable product standard to maintain a connection between how the product is used and how it performs when installed.
Applicable installation/model building codes include Regional and National codes such as ICC, BOCA, SBCCI, UPC and many others.
MIP is an acronym for Male Iron Pipe Thread.
NPT is the acronym for American National Standard Taper Pipe Thread.
FIP is an acronym for Female Iron Pipe Thread.
Please see our installation instructions for complete details.
Dormont has categorized its diameters by series to simplify the selection process. We have created 10, 20, 30, 40, 50 and 60 series connectors. Appliance connector diameter shall not be less than that of the inlet connection to the appliance as provided by the manufacturer and must be of adequate size to provide the total gas demand of the connected appliance.
The correct connector length, once installed, should allow the appliance to be moved from the wall for adequate service/installation access. The connector should be long enough to reach from the gas supply line to the appliance without stretching. Avoid excessive lengths that may cause kinking. Never join two or more connectors together.
Gas connector standards, ANSI Z21.24, Z21.75, & Z21.69, permit connectors up to 72” in length. In the state of Massachusetts, the connector length is currently restricted to a maximum of 36”.
Recommended article:CSA design-certifies gas connectors up to 6’ (72”). Joining two or more connectors is not permitted by installation codes or product standards.
No. Flexible gas connectors can only be used above ground.
No. The gas supply outlet must be in the same room as the appliance and the connector must not be concealed within or run through any wall, floor or partition.
No. According to the requirements of the CSA specification that governs appliance gas connectors, the connector and fittings are designed for use only on the original installation and are not to be reused for another appliance or at another location.
A gas shutoff valve that has been design certified to ANSI Z21.15 is required to be installed 6’ upstream of the gas appliance. This requirement is specified in the National Fuel Gas Code (ANSI Z223.1).
Yes. ANSI Z21.75 covers gas connectors for outdoor applications. Dormont Safety System™ Gas Connectors are design certified to this standard. To further protect the connectors from harsh environmental conditions, Dormont offers an optional PVC coating for outdoor connections.
After the connector has been installed, use a non-corrosive leak detection solution (CHLORIDE FREE) to check for leaks. Do not use dish detergent, laundry soap or other household products as they may contain chlorides. Bubbles will be present at the leak location. Rinse the leak detection solution from the connector and thoroughly dry after the test. Never use an open flame to check for gas leaks.
Natural gas is a colorless, tasteless and, in its pure state, odorless vapor. It is odorized with mercaptin so that its presence can be detected. If an odor is detected, turn off the gas to the appliance and have a qualified professional identify the source of the leak.
No. Only flare fittings supplied with the flexible connector may be used to attach it to the appliance and gas supply source. This is a requirement of the ANSI Standard to ensure that properly designed fittings are used to make safe connections.
Stainless steel flexible gas connectors are designed to last the life of the appliance. Gas connectors should never be re-used. They should be replaced if an appliance is moved to another location, a new appliance is installed or if the connector is damaged.
The appliance can be moved periodically to inspect the connector or clean behind the appliance. Use caution when moving the appliance so the connector is not damaged by crushing or over stretching.
Gas connectors are designed to resist crushing and tearing under normal usage conditions. Stainless steel is an excellent material choice to protect gas connectors from corrosion. As stated on the warning tag, gas connectors should not come in direct contact with soldering fluxes or chemicals, particularly those containing chlorides.
Pressure drop is the difference between the inlet pressure and the outlet pressure of the gas connector. The following are a few application rules regarding pressure drop:
The sum of the appliance gas pressure requirement (appliance nameplate requirement) and the connector pressure drop must be equal to or less than the gas supply pressure in order for the appliance to operate at maximum performance.
Flow rates provided in BTU flow capacity charts are determined at ½” water column (WC) pressure drop. When using 0.2” water column pressure drop, capacity can be determined by multiplying the values in the BTU flow chart by 0.632. For capacities at conditions other than noted, contact Dormont.
PSI is a unit of pressure measurement that means pounds per square inch.
Dormont connectors, and all other gas appliance connectors, are approved for use up to ½ psig maximum operating pressure.
Hi,
I've always heard you shouldn't re-use flare-terminated gas flex line, but I've never heard exactly why.
In a bit of an emergency (caused by my own poor planning of course) I was stuck with buying the longest piece of 3/4" stainless, plastic coated flex hose available at one of the big box hardware store: a mere 24 inches. Set me back a good $36. Later I found the 36" piece I really needed two blocks from my house, for about 1/3 the price.
Since it's been installed less than a week, it's sorely tempting to return that piece I no longer need. If I had used it with steel fittings, I wouldn't think of returning it. But this is stainless (tubing) on brass fittings: that stainless should be pretty tough stuff. Does the act of connecting it for the first time distend the tubing enough for it to be useless for a second go-round?
Can't wait to watch the fur fly on this one... let's show some passion here, people....
-Jeff
346
0
0
All Comments (0)
If you are interested in sending in a Guest Blogger Submission,welcome to write for us!
Comments