NGA 21 - LOCATING AND MARKING OF FACILITIES (FIXING UP,
8/14/18) EXAM QUESTIONS AND ANSWERS
The most important reason for accurate and on-time pipe locating is - CORRECT ANSWER✅✅Public
Safety
Damage Prevention - CORRECT ANSWER✅✅Knowing where all utilities are located prior to digging is
crucial in preventing damage to underground facilities caused by excavating. Before digging, you must
notify excavators and the general public. Acquire the location requests programs along with Utility
locating program. Correctly mark underground facilities before excavating. Advance knowledge of
systems in need of maintenance or repairs promotes good work and minimizes public inconvenience.
Long-Range Planning - CORRECT ANSWER✅✅Before these plans can become developed for the
location of future underground utilities, the location of the existing underground structures in the area
must be established. This provides information needed to estimate system costs and system design.
Maintenance - CORRECT ANSWER✅✅Both emergency and scheduled procedures are extremely
important to the safety operations of a natural gas system. To respond quickly, efficiently, and safely is
essential to this procedure.
Map Verification - CORRECT ANSWER✅✅Map verification and updating is an area of operation that is
on-going. To be assured the maps are accurate, the location of old and new underground pipes and
valves must be accepted and documented based on company policy. Inform excavator operator and
contact appropriate company personnel if you cannot locate a facility because of inaccurate maps
and/or electronic malfunction.
Planning for Expansion or Replacement - CORRECT ANSWER✅✅New underground systems may have to
be installed near existing systems for improvements, replacements, or installed as a entirely new
system. A lack of knowledge of what utilities can be encountered when excavating increases risk and
cost of the job. To prevent this, underground structures in the affected area be located and marked.
Site Survey - CORRECT ANSWER✅✅Always to be conducted before you begin locating to ensure; All
conditions are acceptable and there is nothing that could negatively impact location accuracy. The
correct location. The scope of the work area description is clear.
, Maps - CORRECT ANSWER✅✅The most important method of locating underground gas pipes is to refer
to a map of the gas system being considered. Provides various types of information; pipe size, pressure
in pipe, type of coating, material used in pipe, and location of valves. Utility maps must be kept current.
Hand Digging - CORRECT ANSWER✅✅If necessary, used to locate a pipeline. Any excavation involving
nonmechanized tools or equipment.
Visual Indication - CORRECT ANSWER✅✅Above ground markings and physical features on a map do not
always provide the exact location of the pipe. Information on the line markers must include name and
phone number of the pipeline operator.
Electronic Locators - CORRECT ANSWER✅✅The main method used to locate buried metal facilities or
locator wires on PE pipes. The effectiveness of different instruments depends upon the frequency of the
signal, the type of material used for the conductor, and the soil condition.
All Modern Pipe Locating Equipment Operate By - CORRECT ANSWER✅✅Inducing an electromagnetic
signal on a metallic facility (pipe or wire/cable)
The signal induced on the conductor (or the pipe) is similar to all electric current - CORRECT
ANSWER✅✅Follows the path with least resistance. When the pipe is energized with the induced
voltage from the transmitter- a magnetic field is produced in the shape of concentric circles which
spreads along the pipe.
Conductor - CORRECT ANSWER✅✅The buried metallic pipe or cable being traced
Transmitter - CORRECT ANSWER✅✅A voltage that is induced on the pipe cable
Locators do not locate buried facilities, instead they - CORRECT ANSWER✅✅detect electromagnetic
signals radiating from the metallic wire or cables and pipes.
The Locating Signal is produced by - CORRECT ANSWER✅✅the flow of the alternating current (AC)
which creates an electromagnetic field. The field then radiates from the line, and this is known as the
signal.
8/14/18) EXAM QUESTIONS AND ANSWERS
The most important reason for accurate and on-time pipe locating is - CORRECT ANSWER✅✅Public
Safety
Damage Prevention - CORRECT ANSWER✅✅Knowing where all utilities are located prior to digging is
crucial in preventing damage to underground facilities caused by excavating. Before digging, you must
notify excavators and the general public. Acquire the location requests programs along with Utility
locating program. Correctly mark underground facilities before excavating. Advance knowledge of
systems in need of maintenance or repairs promotes good work and minimizes public inconvenience.
Long-Range Planning - CORRECT ANSWER✅✅Before these plans can become developed for the
location of future underground utilities, the location of the existing underground structures in the area
must be established. This provides information needed to estimate system costs and system design.
Maintenance - CORRECT ANSWER✅✅Both emergency and scheduled procedures are extremely
important to the safety operations of a natural gas system. To respond quickly, efficiently, and safely is
essential to this procedure.
Map Verification - CORRECT ANSWER✅✅Map verification and updating is an area of operation that is
on-going. To be assured the maps are accurate, the location of old and new underground pipes and
valves must be accepted and documented based on company policy. Inform excavator operator and
contact appropriate company personnel if you cannot locate a facility because of inaccurate maps
and/or electronic malfunction.
Planning for Expansion or Replacement - CORRECT ANSWER✅✅New underground systems may have to
be installed near existing systems for improvements, replacements, or installed as a entirely new
system. A lack of knowledge of what utilities can be encountered when excavating increases risk and
cost of the job. To prevent this, underground structures in the affected area be located and marked.
Site Survey - CORRECT ANSWER✅✅Always to be conducted before you begin locating to ensure; All
conditions are acceptable and there is nothing that could negatively impact location accuracy. The
correct location. The scope of the work area description is clear.
, Maps - CORRECT ANSWER✅✅The most important method of locating underground gas pipes is to refer
to a map of the gas system being considered. Provides various types of information; pipe size, pressure
in pipe, type of coating, material used in pipe, and location of valves. Utility maps must be kept current.
Hand Digging - CORRECT ANSWER✅✅If necessary, used to locate a pipeline. Any excavation involving
nonmechanized tools or equipment.
Visual Indication - CORRECT ANSWER✅✅Above ground markings and physical features on a map do not
always provide the exact location of the pipe. Information on the line markers must include name and
phone number of the pipeline operator.
Electronic Locators - CORRECT ANSWER✅✅The main method used to locate buried metal facilities or
locator wires on PE pipes. The effectiveness of different instruments depends upon the frequency of the
signal, the type of material used for the conductor, and the soil condition.
All Modern Pipe Locating Equipment Operate By - CORRECT ANSWER✅✅Inducing an electromagnetic
signal on a metallic facility (pipe or wire/cable)
The signal induced on the conductor (or the pipe) is similar to all electric current - CORRECT
ANSWER✅✅Follows the path with least resistance. When the pipe is energized with the induced
voltage from the transmitter- a magnetic field is produced in the shape of concentric circles which
spreads along the pipe.
Conductor - CORRECT ANSWER✅✅The buried metallic pipe or cable being traced
Transmitter - CORRECT ANSWER✅✅A voltage that is induced on the pipe cable
Locators do not locate buried facilities, instead they - CORRECT ANSWER✅✅detect electromagnetic
signals radiating from the metallic wire or cables and pipes.
The Locating Signal is produced by - CORRECT ANSWER✅✅the flow of the alternating current (AC)
which creates an electromagnetic field. The field then radiates from the line, and this is known as the
signal.
