1. What is the primary code that governs fuel gas installations in Minnesota?
ANSWER The Minnesota Fuel Gas Code, based on the International Fuel Gas
Code (IFGC) with Minnesota amendments.
2. What is the minimum burial depth for gas service lines in Minnesota?
ANSWER 18 inches minimum, or 12 inches if installed in a casing.
3. What type of pipe is NOT approved for underground gas service? ANSWER
Galvanized steel pipe is not approved for direct burial gas service.
4. What is the maximum allowable pressure for low-pressure gas systems?
ANSWER 0.5 psi (14 inches water column).
5. What is the minimum clearance required between a gas meter and an ignition
source? ANSWER 3 feet minimum clearance from ignition sources.
6. What is the maximum length allowed for a flexible gas connector?
ANSWER 6 feet maximum length for appliance flexible connectors.
7. What is the minimum pipe size allowed for a residential gas service line?
ANSWER 1/2 inch minimum for residential service lines.
8. What pressure testing is required for new gas piping systems? ANSWER
Test at 1.5 times operating pressure for a minimum of 10 minutes.
9. What is the minimum clearance between gas piping and electrical panels?
ANSWER 3 feet minimum clearance from electrical service equipment.
10. What type of joint is required for gas piping in concealed locations?
ANSWER Only welded, brazed, or mechanical joints are permitted in
concealed locations.
11. What is the maximum operating pressure for intermediate pressure systems?
ANSWER Greater than 0.5 psi but not exceeding 5 psi.
,12. What is required when gas piping passes through a foundation wall?
ANSWER A protective sleeve or casing with sealed ends.
13. What is the minimum thickness for steel pipe used in gas systems?
ANSWER Schedule 40 steel pipe minimum for most applications.
14. What is the maximum pressure drop allowed in a gas piping system?
ANSWER 0.5 inches water column pressure drop maximum.
15. What type of valve is required as the main shutoff for gas service?
ANSWER A readily accessible manual shutoff valve.
16. What is the minimum clearance between gas piping and a chimney?
ANSWER 6 inches minimum clearance from masonry chimneys.
17. What is required for gas piping that penetrates a fire-rated assembly?
ANSWER Fire-stopping materials and proper firestopping methods.
18. What is the maximum spacing for gas pipe supports? ANSWER Supports
every 6 feet for horizontal runs, every floor for vertical runs.
19. What pressure is considered high pressure in gas systems? ANSWER
Greater than 5 psi is considered high pressure.
20. What is required for testing gas piping systems? ANSWER Pressure
testing with air, nitrogen, or inert gas - never with oxygen.
21. What is the minimum working pressure rating for gas appliance connectors?
ANSWER Rated for the maximum system pressure but not less than 0.5 psi.
22. What is required when installing gas piping in corrosive environments?
ANSWER Corrosion-resistant materials or proper protective coatings.
23. What is the minimum clearance between gas meters and building openings?
ANSWER 3 feet from windows, doors, and air intakes below meter level.
24. What type of thread sealant is approved for gas piping? ANSWER Pipe
dope approved for use with natural gas or LP gas.
25. What is the maximum allowable leak rate for gas piping systems?
ANSWER No detectable leaks when tested with leak detection solution.
26. What is required for gas appliance venting systems? ANSWER Proper
venting to the outdoors following manufacturer specifications.
27. What is the minimum clearance for gas equipment rooms? ANSWER
Adequate clearance for service and ventilation as per code requirements.
, 28. What is required for gas piping labels and marking? ANSWER Proper
identification and marking of gas piping systems.
29. What is the maximum number of fittings allowed in a gas piping run?
ANSWER No specific limit, but minimize fittings to reduce pressure drop.
30. What is required for gas emergency shutoff procedures? ANSWER Clear
marking and accessibility of emergency shutoff valves.
31. What type of material is approved for gas service lines? ANSWER PE
(polyethylene), steel, or approved metallic materials.
32. What is the minimum cover requirement for PE gas piping? ANSWER 18
inches minimum cover with tracer wire installed.
33. What is required for gas appliance installation clearances? ANSWER
Follow manufacturer specifications and code minimum requirements.
34. What is the maximum operating temperature for PE gas piping? ANSWER
140°F maximum operating temperature for PE pipe.
35. What is required for gas meter installation? ANSWER Level, accessible
location with proper clearances and support.
36. What is the minimum wall thickness for steel gas service lines? ANSWER
As specified in the gas code based on pressure and diameter.
37. What is required for gas piping slope and drainage? ANSWER Proper
slope to prevent water accumulation and provide drainage.
38. What is the maximum pressure for appliance gas train testing? ANSWER
Test at 1.5 times normal operating pressure.
39. What is required for gas appliance combustion air? ANSWER Adequate
combustion and ventilation air per code requirements.
40. What is the minimum radius for bends in gas piping? ANSWER 6 times
the pipe diameter for bends in steel pipe.
41. What is required for gas appliance electrical connections? ANSWER
Proper grounding and electrical connections per electrical code.
42. What is the maximum length for corrugated stainless steel tubing (CSST)?
ANSWER Follow manufacturer specifications for maximum lengths.
43. What is required for gas appliance draft controls? ANSWER Proper draft
control devices as required by manufacturer.
ANSWER The Minnesota Fuel Gas Code, based on the International Fuel Gas
Code (IFGC) with Minnesota amendments.
2. What is the minimum burial depth for gas service lines in Minnesota?
ANSWER 18 inches minimum, or 12 inches if installed in a casing.
3. What type of pipe is NOT approved for underground gas service? ANSWER
Galvanized steel pipe is not approved for direct burial gas service.
4. What is the maximum allowable pressure for low-pressure gas systems?
ANSWER 0.5 psi (14 inches water column).
5. What is the minimum clearance required between a gas meter and an ignition
source? ANSWER 3 feet minimum clearance from ignition sources.
6. What is the maximum length allowed for a flexible gas connector?
ANSWER 6 feet maximum length for appliance flexible connectors.
7. What is the minimum pipe size allowed for a residential gas service line?
ANSWER 1/2 inch minimum for residential service lines.
8. What pressure testing is required for new gas piping systems? ANSWER
Test at 1.5 times operating pressure for a minimum of 10 minutes.
9. What is the minimum clearance between gas piping and electrical panels?
ANSWER 3 feet minimum clearance from electrical service equipment.
10. What type of joint is required for gas piping in concealed locations?
ANSWER Only welded, brazed, or mechanical joints are permitted in
concealed locations.
11. What is the maximum operating pressure for intermediate pressure systems?
ANSWER Greater than 0.5 psi but not exceeding 5 psi.
,12. What is required when gas piping passes through a foundation wall?
ANSWER A protective sleeve or casing with sealed ends.
13. What is the minimum thickness for steel pipe used in gas systems?
ANSWER Schedule 40 steel pipe minimum for most applications.
14. What is the maximum pressure drop allowed in a gas piping system?
ANSWER 0.5 inches water column pressure drop maximum.
15. What type of valve is required as the main shutoff for gas service?
ANSWER A readily accessible manual shutoff valve.
16. What is the minimum clearance between gas piping and a chimney?
ANSWER 6 inches minimum clearance from masonry chimneys.
17. What is required for gas piping that penetrates a fire-rated assembly?
ANSWER Fire-stopping materials and proper firestopping methods.
18. What is the maximum spacing for gas pipe supports? ANSWER Supports
every 6 feet for horizontal runs, every floor for vertical runs.
19. What pressure is considered high pressure in gas systems? ANSWER
Greater than 5 psi is considered high pressure.
20. What is required for testing gas piping systems? ANSWER Pressure
testing with air, nitrogen, or inert gas - never with oxygen.
21. What is the minimum working pressure rating for gas appliance connectors?
ANSWER Rated for the maximum system pressure but not less than 0.5 psi.
22. What is required when installing gas piping in corrosive environments?
ANSWER Corrosion-resistant materials or proper protective coatings.
23. What is the minimum clearance between gas meters and building openings?
ANSWER 3 feet from windows, doors, and air intakes below meter level.
24. What type of thread sealant is approved for gas piping? ANSWER Pipe
dope approved for use with natural gas or LP gas.
25. What is the maximum allowable leak rate for gas piping systems?
ANSWER No detectable leaks when tested with leak detection solution.
26. What is required for gas appliance venting systems? ANSWER Proper
venting to the outdoors following manufacturer specifications.
27. What is the minimum clearance for gas equipment rooms? ANSWER
Adequate clearance for service and ventilation as per code requirements.
, 28. What is required for gas piping labels and marking? ANSWER Proper
identification and marking of gas piping systems.
29. What is the maximum number of fittings allowed in a gas piping run?
ANSWER No specific limit, but minimize fittings to reduce pressure drop.
30. What is required for gas emergency shutoff procedures? ANSWER Clear
marking and accessibility of emergency shutoff valves.
31. What type of material is approved for gas service lines? ANSWER PE
(polyethylene), steel, or approved metallic materials.
32. What is the minimum cover requirement for PE gas piping? ANSWER 18
inches minimum cover with tracer wire installed.
33. What is required for gas appliance installation clearances? ANSWER
Follow manufacturer specifications and code minimum requirements.
34. What is the maximum operating temperature for PE gas piping? ANSWER
140°F maximum operating temperature for PE pipe.
35. What is required for gas meter installation? ANSWER Level, accessible
location with proper clearances and support.
36. What is the minimum wall thickness for steel gas service lines? ANSWER
As specified in the gas code based on pressure and diameter.
37. What is required for gas piping slope and drainage? ANSWER Proper
slope to prevent water accumulation and provide drainage.
38. What is the maximum pressure for appliance gas train testing? ANSWER
Test at 1.5 times normal operating pressure.
39. What is required for gas appliance combustion air? ANSWER Adequate
combustion and ventilation air per code requirements.
40. What is the minimum radius for bends in gas piping? ANSWER 6 times
the pipe diameter for bends in steel pipe.
41. What is required for gas appliance electrical connections? ANSWER
Proper grounding and electrical connections per electrical code.
42. What is the maximum length for corrugated stainless steel tubing (CSST)?
ANSWER Follow manufacturer specifications for maximum lengths.
43. What is required for gas appliance draft controls? ANSWER Proper draft
control devices as required by manufacturer.
