Maine Propane & Natural Gas Technician Practice Exam

These questions are part of the practice quiz. Start practicing

• A commercial building's chimney must be what size if it serves one Category 1 natural draft vented appliance with a 341,000 Btu input?
• What is the minimum melting point for materials used for brazing joints on a gas pipe?
• In a standard propane equipment installation, what is a common safety device used to protect against overpressure?
• What does BTU stand for?
• Why is checking the gas line for corrosion crucial?
• How many openings are required for combustion air obtained from indoors on the same story?
• According to the NFPA 54 National Fuel Gas Code, what is the maximum operating pressure for regulated gas piping systems?
• What is the maximum distance between pipe supports for 1" black steel gas pipe?
• Which of the following is a sign that a gas appliance may need service?
• What is the maximum horizontal length for a single-wall vent connector?
• What is the minimum horizontal clearance from combustible material for an unlisted outdoor open flame illuminating appliance with a flame height of 24 inches above the burner head?
• Which type of valve is typically used for propane tanks?
• What is the maximum allowable pressure for residential propane systems?
• What is the maximum temperature that a clay flue liner must withstand without cracking?
• Which type of copper tubing is specified for the installation of the gas line?
• What is a common application of propane in residential areas?
• What is the minimum clearance for a draft hood relief opening from any surface other than what draft hood is connected to?
• An appliance installed in an attic shall have a platform to service in front of the appliance. What is the minimum size of the structure?
• What is the maximum length of a 10" horizontal vent connector?
• What is the minimum clearance required on all sides of an outdoor open flame decorative appliance from combustible materials?
• What is the primary concern when installing gas appliances in confined spaces?
• What is the max allowable pressure for the natural gas system installed with semi-rigid Type K copper tubing?
• What type of gas is primarily used in propane systems?
• What is the minimum vertical distance required for a combustion air intake located on the exterior above ground level?
• Which test medium should never be used for pressure testing gas piping?
• What should you do if you smell gas?
• What is the maximum input capacity for gas appliances operating above 2,000 feet?
• Which type of gas is commonly used for residential heating?
• How is the specific gravity of propane typically represented?
• What is the minimum clearance above grade for a furnace that has been factory sealed to prevent water entry?
• What minimum distance shall be maintained between the edge of a roof and any part of an appliance installed on the roof?
• What size post shall be installed to support a gas supplied illuminating appliance mounted on a post that is 6ft?
• What is the standard method for calculating the minimum required volume of combustion air?
• What type of fittings are used to connect copper tubing in a gas system?
• What should a technician look for if a gas appliance is giving off a strange odor?
• What is the pressure drop specified for the gas line installation in the text provided?
• For a lateral rise in gas piping that exceeds certain lengths, what is a key consideration for maintaining optimal performance?
• What is a common method of leak detection in gas systems?
• For a house built with two 65,000 BTU furnaces and three 55,000 BTU fireplaces, what size L copper gas tube is required from the meter?
• What type of valve is commonly used to manage gas flow in a gas supply system?
• What is the purpose of drip legs in natural gas piping?
• What is the typical pressure drop in inches of water column used for gas piping calculations?
• What is the maximum gas piping system design pressure for systems used inside of a building?
• What is a typical symptom of carbon monoxide poisoning?
• What are the two primary types of gas meters used in natural gas systems?
• When installing a chimney for natural draft appliances, what critical dimension is often specified for ensuring safety?
• What safety measure should be taken when installing gas appliances?
• What color is propane when inside a tank?
• What is the minimum burial depth for gas lines in areas where external forces could damage the pipe?
• What is the chemical formula for propane?
• In gas line installations, what material is typically required for a sediment trap?
• What is the primary difference between propane and natural gas?
• What is the role of the anode rod in a gas water heater?
• What is the minimum height for guards mounted above a roof-mounted equipment platform for service?
• What is the primary reason for installing a gas line with a certain pipe size?
• What is the common unit used to measure the input of natural gas appliances?
• A 4" natural gas pipe must be purged with inert gas before servicing. What is the maximum length of pipe before purging is required?
• An unlisted floor furnace must have a temperature limit control that will shut off the gas supply if the air temperature exceeds what level above room temperature?
• A fuel-fired appliance is installed in a garage. What is the minimum distance above the floor that the source of burner ignition shall be located?
• What is the minimum required clearance for combustible materials from the front of a central heating steam boiler that operates at less than 15 psi?
• Which gasket material is deemed unacceptable for use in gas piping flanges?
• On what principle does a gas appliance operate?
• What is the minimum horizontal clearance required for a listed countertop food service appliance such as coffee brewers and food warmers?
• What size steel pipe is needed to supply two large ovens with a combined total of 1225 cubic feet of gas per hour 61 feet away from the meter?
• What is the main safety concern with propane storage?
• When an appliance is installed in an attic space, what is the maximum distance from the attic access that the appliance can be installed when measured along the centerline?
• What is the maximum distance between horizontal supports for half inch OD copper tubing used for gas supply piping?
• What is the minimum vertical height for a Type B-W gas vent above the bottom of a wall furnace?
• What is the maximum BTU per hour input rating for a listed unvented wall-mounted room heater equipped with an oxygen depletion safety shut off system being installed in a bedroom?
• What is the appropriate action if an appliance is directly under a roof structure in an attic space?
• What is the minimum size dimension of outdoor combustion air openings?
• What should be ensured when installing a vent system for a gas appliance?
• What clearance is necessary around appliances that produce open flames to reduce fire hazards?
• What device is used to extinguish a fire in a propane burner?
• What size corrugated stainless steel tubing should be installed to transport 217,000 cubic feet per hour of natural gas to an appliance 98 feet away?
• For gas lines installed in potentially wet areas, what slope is recommended to prevent issues with condensation?
• What is the maximum temperature of the combustion products for a medium-heat, nonresidential appliance?
• When the gas supply is delivered to a building at 2 psi, an over pressure protection device shall be installed to protect appliances designed to operate at what pressure?
• What type of fire extinguisher is suitable for propane fires?
• What is the minimum clearance required for an unlisted clothes dryer from the exhaust duct to combustible materials?
• What size chimney is needed for a factory with a total BTU input of 962,000 from two Category I fan-assisted appliances?
• Which factor can influence the size of gas piping required for an appliance?
• What is the minimum required clearance for a vent connector on a medium-heat appliance using a single-wall metal pipe?
• How far must horizontal warm air outlet registers for a floor furnace be placed away from the nearest wall?
• What is the boiling point of natural gas?
• What is the minimal burial depth for an underground gas line installation?
• What is the purpose of a service valve?
• What is the minimum termination height of a single-wall metal pipe vent above the roof?
• A residential-type chimney shall terminate what minimum distance above the highest point of the roof?
• What is one potential cause of gas regulator failure?
• What instrument is typically used to measure gas pressure?
• What is a major advantage of using CSST for gas distribution?
• For a grocery store heated by rooftop gas-fired units, what size steel pipe is required to supply gas from the meter?
• When a gas manifold is located in a remote area, what is the maximum distance the shutoff valve can be from the appliance?
• What type of air is introduced into a burner that mixes with the gas before it reaches the port or ports?
• What must be used to line an excavation deeper than 12 inches when installing a mechanical appliance?
• What is the impact of a 0.5 in. w.c. pressure drop in a gas line system with an inlet pressure of 11.0 in w.c.?
• What type of venting system shall be used for a listed vented wall furnace?
• What type of maintenance should be regularly performed on gas appliances?
• What is the maximum allowable pressure drop for gas piping systems in structures?
• What is the maximum hanger support spacing for horizontal 1" O.D. smooth wall tubing?
• What is the minimum required clearance for an unlisted pool heater on all sides and rear?
• What is one of the primary indicators of improper combustion in a gas appliance?
• What is the minimum required clearance for a propane tank from any structure?
• What is the importance of a cleanout in relation to chimney installations?
• What size of corrugated stainless steel tubing is required to deliver 248,000 BTU of propane to an appliance located 82 feet away?
• What can occur if a gas appliance is not vented properly?
• What is the minimum thickness of a steel striker barrier required for gas tubing protection?
• What is the atmospheric pressure (psia) of air on the surface of earth at sea level?
• What standard should a compressed natural gas (CNG) motor vehicle fueling facility comply with?
• How often should gas appliances be serviced?
• What device is responsible for monitoring the amount of gas used?
• What action should be taken if a gas appliance produces yellow flames?
• When handling propane tanks, what is a key safety tip?
• What is the maximum distance off the ceiling for an indoor combustion air opening installation?
• At what temperature should LP-Gas vapor not condense back into a liquid?
• What is the minimum size opening for outdoor combustion air intakes?
• What materials are considered suitable for underground natural gas pipelines?
• What is a common application for corrugated stainless steel tubing?
• At what inlet pressure is the gas supply considered less than safe for residential use?
• What does an air shutter on a gas burner control?
• What is the recommended size of tubing to install for a gas line that is 520 feet long with a pressure drop of 0.3 in. w.c.?
• What is the minimum length nipple that can be used for a sediment trap on a gas line?
• What are the minimum size screen openings for exterior combustion air intakes that have louvres or grills covering the openings?
• What indicates an over-pressure issue in a natural gas pipeline?
• What safety equipment is necessary when working with gas systems?
• What is the recommended minimum clearance of a unlisted floor furnace's air outlet register from the register to ceiling?
• What is the maximum distance a gas shut-off valve can be installed from the equipment it serves?
• A 127 foot long gas line in metallic pipe requires which size when carrying undiluted LP gas at specified conditions?
• What is the minimum thickness of an 8" galvanized steel low-heat appliance vent connector?
• What material is typically used for pressure testing gas piping?
• What is the approximate length of the threaded portion of a 1-1/4" metallic pipe used for gas supply?
• What is the typical temperature setting for hot water heaters using propane?
• Which gas typically requires a special license for commercial use?
• For a material to be considered non-combustible, it must pass the ASTM E 136 test at what temperature?
• In a gas piping system, what should be examined to prevent unnecessary pressure loss?
• How much venting is necessary for a gas appliance installed indoors compared to one installed outdoors?
• What safety measure should be taken when working with propane appliances?
• An air conditioning system controls all of the following EXCEPT?
• If more than two 90° elbows are used in a vent connector, by what percentage should the capacity of the connector be reduced for each additional elbow?
• What is the minimum amount of time required to perform a pressure test on a gas line in a single-family home?
• How are underground propane tanks typically installed?
• When all combustion air is supplied by a mechanical system, what is the amount of combustion air required per 1000 Btu/hr of appliance input?
• What is the MAXIMUM length of an indoor nonmetallic gas connector hose for gas equipment that requires mobility?
• What can happen if a propane hot water heater is set too high?
• Listed unit heaters suspended from the ceiling should maintain a minimum clearance of what height from combustible materials?
• What is the required minimum distance a propane tank must be from an ignition source?
• Why is it critical to maintain correct clearance distances when installing gas appliances?
• What is a potential hazard of both propane and natural gas?
• What is the minimum gauge size of tracer wire required for nonmetallic pipe used for underground gas?
• For a low pressure boiler using undiluted propane gas and located 156 feet away from the gas meter, which size corrugated stainless steel tubing should be used to supply an 820,000 BTU of gas per hour boiler?
• What is the minimum size clear access opening for a trapdoor or scuttle used to access appliances installed on a roof?
• What is the function of a draft hood in a gas appliance?
• When cutting threads on a 2" steel pipe used for a gas line, what is the approximate length of the threaded portion for each joint?
• Which gas is heavier than air and can accumulate in low areas?
• When cutting threads on a 1" steel pipe for a gas line, how many threads should be cut for each joint?
• Recirculating direct-fired industrial air heaters shall receive outside ventilation air into the space at a rate determined by what?
• Which of the following is necessary for the efficient operation of gas appliances?
• What is the minimum distance a conduit must extend beyond the end of a building for an underground gas line?
• What is the standard pressure drop allowed for natural gas supply in residential settings?
• For a residential boiler with a gas conversion burner, what is the minimum clearance from combustible materials?
• What is the primary purpose of a pressure regulator in a propane system?
• What is the maximum distance an electrical disconnect switch can be from the air-conditioning unit it serves?
• What minimum amount of slope per foot should a vent connector have upward toward the chimney?
• What hazard is associated with improper installation of gas tubing?
• What is the primary purpose of venting propane appliances?
• What does a gas detector measure?
• When terminating a chimney for a medium heat appliance, what is the minimum extension height above the nearest building?
• What size Type B chimney is needed for a house with a 19 foot tall chimney and a total of 185,000 BTU input from one Category I natural draft vented appliance?
• How should gas lines be routed when installing?
• What function does a draft hood serve in a gas appliance?
• Which ANSI standard must PVC plastic pipe used for connecting gas pressure regulator vents conform to?
• Which of the following materials is NOT approved for gas piping?
• When replacing a bad valve on a 10" natural gas main pipe, how much of the pipe must be purged with inert gas before starting work?
• What is the minimum distance a single-wall metal vent pipe must be installed above and below a roof made of combustible material?
• What feature is important for propane tank security?
• What is a typical setback temperature for a programmable thermostat used with gas heating?
• What component is essential for maintaining safe operation in gas appliances with potential oxygen depletion?
• LP-Gas systems designed to operate in very cold conditions shall mix the propane with butane to prevent the LP-Gas vapor from condensing back to a liquid at what operation temperature?
• When should you report a gas leak?
• What is the flash point of propane?
• What is the specific gravity of natural gas used in a 520-foot gas line installation?
• What is the maximum horizontal length of a Type B double-wall vent connector relative to chimney height?
• Which of the following is necessary for proper gas line installation?
• When flammable or corrosive fumes are present, which of the following is NOT considered a hazardous material?
• What is the reduction in venting capacity when 90 degree elbows are used in a common vent?
• Fuel cell power plants with an output greater than 50 kW should comply with which NFPA Standard?
• What size CSST stainless steel tubing is needed to supply 220 cubic feet of natural gas per hour from 34 feet away from the meter?
• What is the purpose of a gas venting system?
• What is the minimum thickness for a 20" steel chimney connector for a medium heat appliance?
• What type of maintenance is most recommended for gas appliances?
• What does the specific gravity of 1.50 indicate about the LP gas in piping installations?
• Which type of regulator is used in series for emergency pressure control in gas piping systems?
• What is the primary role of an orifice in a gas burner?
• What size chimney should be installed for a home with one Category I gas appliance and specified conditions, in order to accommodate a BTU input of 92,000?
• What is the maximum temperature of the combustion products of a low-heat, nonresidential appliance?
• What is the maximum btu/hr input allowed for an unlisted decorative appliance in a vented fireplace with an 18-foot chimney?
• What type of piping is recommended for high-pressure gas distribution?
• What is the maximum operating pressure for a low pressure steam boiler?
• Which type of piping is commonly used for natural gas in residential installations?
• At what elevation should gas appliances have their input reduced by 4% for each 1000 feet above sea level?
• What is the primary purpose of a gas valve in a propane system?
• What is the minimum distance vertically above an adjoining grade for an outdoor combustion air intake opening?
• What pressure drop is acceptable for residential gas piping installations?
• All steam and hot water boilers are required to have a pressure relief valve. What is one condition that is NOT required for installation?
• What does NFPA stand for in relation to gas safety?
• What is a common symptom indicating propane tank overfilling?
• What safety equipment is crucial for handling propane fuel?
• What is the minimum clearance required for the exhaust duct of a Type 2 clothes dryer from combustible materials?
• Which agency regulates natural gas pipelines in the United States?
• What is the purpose of an emergency shutoff valve?
• What should technicians check when performing maintenance on gas appliances?
• In areas where condensation may form, how should gas piping be sloped?
• What is the minimum length of the unthreaded portion of a gas piping outlet extending beyond a patio surface?
• When is it necessary to perform a pressure test on a gas system?
• Why is it important to ensure proper gas line routing in installations?
• What should be regularly inspected in a natural gas furnace?
• What type of valve shall be used at the point of connection when a gas system has supplementary standby gas connected downstream of the meter?
• In what condition should propane tanks be stored to prevent hazards?
• What is the minimum width of an unobstructed passageway with solid flooring to access equipment installed in an attic?
• What are the signs of a potential gas leak?
• What is the minimum clearance required on the sides and the rear of an unlisted vented gas fireplace?
• Which material is approved for use as combustion air ducts?
• In accordance with installation standards, which aspect of a chimney must accommodate the total BTU input from gas appliances?
• What can result from an incorrect air-to-gas ratio in a gas burner?
• How much of the bottom compartment should be factory sealed in a furnace to prevent water entry?
• What is the minimum clearance for a listed duct furnace from adjacent combustible materials?
• Which reference standard covers the storage of liquid propane gas?
• What is the minimum test pressure required for newly installed gas piping?
• What is the minimum time required to perform a pressure test on a 1,250 foot steel gas line?
• Appliances installed in an underground parking garage shall meet which of the following standards?
• What is the required distance between the upper edge of a cleanout and the lower edge of the lowest inlet to a masonry chimney?
• What is the minimum distance above grade that the bottom of a horizontal mechanical draft exhaust must terminate?
• What is the minimum distance that a floor shall be protected by millboard and sheet metal around a food service appliance installed on a combustible floor?
• A building with roof-mounted, gas-fired equipment shall have a permanent inside means of access when the height of the building is more than what height?
• What is the distance from the top of a vent pipe to a roof penetration for effective air circulation?
• What is the minimum height requirement for vent terminals to ensure proper ventilation?
• Outdoor combustion air obtained through one-permanent-opening method should have a minimum free area of what size?
• What size K or L semi-rigid copper tubing should be installed to supply 205 cu. ft. of gas per hour at a specific gravity of 0.60?
• In addition to measuring pressure, what can a manometer also be used for?