I202412 NOPV Response

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608• BOISE,IDAHO 83707• [phone]• FAX:[phone]
October 11,2024
Mr.Jeff Brooks,Programs Manager
Idaho Public Utility Commission
PO Box 83720
Boise,ID 83720-0074
Subject:Response to the Notice of Probable Violation dated September 4,2024(Report#1202412)
Dear Mr.Brooks,
This letter is intended to address one(1)notice of probable violation stemming from a construction inspection
conducted by the Idaho Public Utilities Commission(IPUC)on September 3,2024,on service line 413-1964 of
Intermountain Gas Company(IGC)pursuant of Chapter 601 Title,49,United States Code.
PROBABLE VIOLATION
1. 49 CFR§192.605 Procedural manual for operations, maintenance, and emergencies.
(a) General. Each operator shall prepare and follow for each pipeline,a manual of written
procedures for conducting operations and maintenance activities and for emergency response.For
transmission lines,the manual must also include procedures for handling abnormal operations. This
manual must be reviewed and updated by the operator at intervals not exceeding 15 months,but at
least once each calendar year.This manual must be prepared before operations of a pipeline system
commence.Appropriate parts of the manual must be kept at locations where operations and
maintenance activities are conducted.
2. OPS 307 Polyethylene(PE)Main and Service Construction
5.11.Butt fusions shall be made in accordance with TR-33 Appendix A.
NOTE: TR-33 was used to develop ASTM 2620-19, making the level of safety in TR-33 equivalent to
that of ASTM 2620-19. Connections shall be made by butt fusion or electrofusion.
3. Generic Butt Fusion Joining Procedure for Field Joining of Pol}ethylene Pipe TR-33 (2012)
Appendix A
1.0. Secure
Clean the inside and outside of the pipe to be joined by wiping with a clean lint-free cloth.
Remove all foreign matter. Clamp the components in the machine. Check alignment of the ends
adjust as needed.
2.0. Face
The pipe ends must be faced to establish clean,parallel mating surfaces.Most,if not all,
equipment manufacturers have incorporated the rotating planer black design in their facers to
accomplish this goal.Facing is continued until a minimal distance exists between the fixed and
movable jaw bushings.Open the jaws and remove the facer.Remove any pipe chips from the
facing operation and any foreign matter with a clean,lint-free cotton cloth.Bring the pipe ends
together with a minimal force and inspect the face off.A visual inspection of this operation
should verify that faces are square,perpendicular to the pipe centerline on each pipe end and
with no detectable gap.
3.0.Align
The pipe profiles must be rounded and aligned with each other to minimize mismatch(high-
low)of the pipe walls. This can be accomplished by tightening clamping jaws until the outside
diameters of the pipe ends match. The jaws must not be loosened,or the pipe may slip during
fusion.Re-face the pipe ends and remove any chips from re-facing operation with a clean,lint-
free cotton cloth.

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608• BOISE,IDAHO 83707• [phone]• FAX:[phone]
4.0.Melt
Heating tools that simultaneously heat both pipe ends are used to accomplish this operation.
These heating tools are normally furnished with thermometers to measure internal heater
temperature so the operator can monitor the temperature before each joint is made.However,the
thermometer can be used only as general indicator because there is some heat loss from internal
external surfaces,depending on factors such as ambient temperatures and wind conditions.A
pyrometer or other surface temperature-measuring device should be used before the first joint of
the day is made and periodically throughout the day to ensure proper temperature of the heating
tool face that contacts the pipe or fitting ends.Additionally,heating tools are usually equipped
with suspension and alignment guides that center them on the pipe ends. The heater faces that
come into contact with the pipe should be clean,oil-free and coated with nonstick coating as
recommended by the manufacturer to prevent molten plastic from sticking to the heater surfaces.
Remaining molten plastic can interfere with fusion quality and must be removed according to
the tool manufacturer's instructions.Never use chemical cleaners or solvents to clean heating
tool surfaces.
The surface temperatures must be in the temperature range 400-450°F(204-232°C).Install the
heater in the butt fusion machine and bring the pipe ends into full contact with the heater.To
ensure that full and proper contact is made between the pipe ends and the heater,the initial
contact should be under moderate pressure.After holding the pressure very briefly,it should be
released without breaking contact.On larger pipe sizes,initial pressure may be maintained until
a light melt is observed around the circumference of the pipe before releasing pressure.
Continue to hold the components in contact with each other,without force,while a bead of
molten polyethylene develops between the heater and the pipe ends.When the proper bead size
is formed against the heater surfaces all around the pipe or fitting ends,remove the heater.Melt
bead size is dependent on pipe size. See table below for approximate melt bead sizes.
5.0.Joinin
After the heater tool is removed,quickly inspect the pipe ends(NOTE: If a concave melt surface
is observed,unacceptable pressure during heating has occurred and the joint will be low quality.
Do not continue.Allow the component ends to cool completely,and restart at the beginning.
Except for a very brief time to seat the components fully against the heater tool,do not apply
pressure during heating.),then immediately bring the molten pipe ends together with sufficient
fusion force to form a double rollback bead against the pipe wall.
6.0.Hold
Hold the joint immobile under fusion force until the joint has cooled adequately to develop
strength.Allowing proper cooling times under fusion force prior to removal from the clamps of
the machine is important in achieving joint integrity.The fusion force should be held between
the pipe ends for approximately 30-90 seconds per inch of pipe diameter or until the surface of
the melt bead is cool to the touch.
Finding(s)•
IPUC staff observed a contractor make two fusions using incorrect procedures.
Fuse#1,Adjusted for alignment and did not reface prior to installing heating tool for melt.While the pipe
ends were heating and after applying moderate pressure and releasing,IPUC inspector witnessed the fuser
apply variable pressures multiple times during the same fusion with the"dogs"set.After the heater tool was
removed,the individual did not inspect pipe ends for concave prior to joining pipe ends.
Fuse#2,While the pipe ends were heating and after applying moderate pressure and releasing,IPUC
inspector witnessed the fuser apply variable pressure multiple times during the same fusion with the"dogs'
set.After the heater tool was removed,the individual did not inspect pipe ends for concave prior to joining
pipe ends.
During both fuses the individual used the same paper towel on pipe and heating surfaces.

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608• BOISE,IDAHO 83707•[phone]• FAX:[phone]
Intermountain Gas Reslionse
IGC acknowledges the findings brought forth by the IPUC. Operator qualifications were suspended for the
employee who performed the butt fusions and will remain suspended until the employee is retrained by the IGC
Technical Training department and successfully completes the operator qualification requirements for the butt
fusion covered task.
Please contact Josh Sanders at(701)222-7773 with questions or comments.
Respectfully Submitted,
Pat Darras
Vice President,Engineering&Operations Services
Intermountain Gas Company