Residential Connectors FAQ

1. What are the advantages of stainless steel gas connectors?
2. What is the advantage of Dormont’s stainless steel gas connectors?
3. What problems and safety issues are associated with brass connectors?
4. Why do I need a coating?
5. Does the coating need to be yellow?
6. What are EFVs?
7. Do I need an EFV to be up to code?
8. What are flare fittings?
9. What is a “Mismate” thread?
10. What are product standards?
11. What are installation/model building codes?
12. What are the applicable installation/model building codes?
13. What does MIP stand for?
14. What does NPT stand for?
15. What does FIP stand for?
16. How should the connector be installed?
17. How do I choose the right diameter?
18. How do I choose the right length?
19. What is the maximum length of a gas connector?
20. Can you put two hoses together?
21. Can gas connectors be placed underground?
22. Can gas connectors run through a wall?
23. Can I reuse a gas connector?
24. Is a manual gas shut-off valve required by code?
25. Can these connectors be used outdoors?
26. How do I leak test the connector?
27. Can natural gas be detected by scent?
28. Can flare fittings from other manufacturers be used with a Dormont connector?
29. When should a gas connector be replaced?
30. Can the appliance be moved without damaging the connector?
31. Can anything damage a stainless steel connector?
32. What is pressure drop?
33. How does pressure drop affect the gas appliance?
34. How do I select the connector with the correct pressure drop?
35. What is PSI?
36. How many pounds per square inch (PSI) are approved for Dormont connectors?

1. What are the advantages of stainless steel gas connectors?

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).

2. What is the advantage of Dormont’s stainless steel gas connectors?

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.

3. What problems and safety issues are associated with brass connectors?

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.

4. Why do I need a coating?

While stainless steel is a strong and durable metal, Dormont’s Safety Shield® coating provides added protection against corrosive chemicals.

5. Does the coating need to be yellow?

Safety Shield® is provided in a vibrant yellow color, which is the industry-recognized color for gas line identification.

6. What are EFVs?

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.

7. Do I need an EFV to be up to code?

Please contact your local Code Official to determine whether your locality requires appliance EFVs.

8. What are flare fittings?

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.

9. What is a “Mismate” thread?

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.

10. What are product standards?

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).

11. What are installation/model building codes?

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.

12. What are the applicable installation/model building codes?

Applicable installation/model building codes include Regional and National codes such as ICC, BOCA, SBCCI, UPC and many others.

13. What does MIP stand for?

MIP is an acronym for Male Iron Pipe Thread.

14. What does NPT stand for?

NPT is the acronym for American National Standard Taper Pipe Thread.

15. What does FIP stand for?

FIP is an acronym for Female Iron Pipe Thread.

16. How should the connector be installed?

Please see our installation instructions for complete details.

17. How do I choose the right diameter?

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.

18. How do I choose the right length?

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.

19. What is the maximum length of a gas connector?

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”.

20. Can you put two hoses together?

CSA design-certifies gas connectors up to 6’ (72”). Joining two or more connectors is not permitted by installation codes or product standards.

21. Can gas connectors be placed underground?

No. Flexible gas connectors can only be used above ground.

22. Can gas connectors run through a wall?

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.

23. Can I reuse a gas connector?

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.

24. Is a manual gas shut-off valve required by code?

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).

25. Can these connectors be used outdoors?

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.

26. How do I leak test the connector?

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.

27. Can natural gas be detected by scent?

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.

28. Can flare fittings from other manufacturers be used with a Dormont connector?

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.

29. When should a gas connector be replaced?

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.

30. Can the appliance be moved without damaging the connector?

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.

31. Can anything damage a stainless steel connector?

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.

32. What is pressure drop?

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 outlet pressure is always less than the inlet pressure because of flow resistance/frictional losses inside of the connector.
• Flow through the connector increases as the pressure drop increases.
• Pressure drop always decreases when the connector diameter is increased.
• Pressure drop increases as connector length increases.

 

33. How does pressure drop affect the gas appliance?

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.

34. How do I select the connector with the correct pressure drop?

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.

35. What is PSI?

PSI is a unit of pressure measurement that means pounds per square inch.

36. How many pounds per square inch (PSI) are approved for Dormont connectors?

Dormont connectors, and all other gas appliance connectors, are approved for use up to ½ psig maximum operating pressure.