Introduction to Pipe Threading and Roll Grooving
Objectives:
Student will demonstrate an understanding of the different types of pipe
used today
Student will demonstrate an understanding of the methods employed to
join pipe together
Student will demonstrate an understanding of the different types of dies
used in threading pipe
Student will demonstrate an understanding of the process of roll grooving
Student will demonstrate an understanding of the benefits of partnering
with an Evergreen Preferred Supplier for their pipe threading and roll
grooving needs
Types of Pipe
Modern pipe is used to transmit liquids and gases in the fields of plumbing,
heating, refrigeration, power plant operations, refinery operations and many
more. Carbon steel, copper, PVC are probably the most widely used pipe today.
There are many types of pipe used in today's market such as:
1. Commercial Steel Pipe (Black Pipe)
A. Comprises the bulk of the pipe sold in the market today
B. Can be welded or seamless and available in various wall thickness
and a wide range of diameters
2. Galvanized Pipe (Steel Pipe)
A. Galvanized pipe is hot dipped coated inside and out with a layer of zinc
B. Galvanizing helps improve the pipe's corrosion resistance
3. Stainless Steel Pipe
A. Requires "special" pipe tools for threading and cutting
B. More expensive than other types of piping available
C. Used for process piping in food, petroleum, chemical and other
industries
4. PVC
A. Usually glued together but can be threaded or gasket joined if using
schedule 40 or above
5. Copper
A. Used in plumbing trades and can be either soldered, grooved, flared or
compression fitted
6. Polyethylene
A. Used for natural gas or water and can be fused or mechanically joined.
Pipe Weight & Diameter
Pipe Weight:
Pipe can be identified by type, method of manufacture and wall thickness or
"weight". The most common pipe used in the field is schedule 40 wall weight or
"schedule 40". There is also schedule 80, Extra Heavy (E.H.) or Double Extra
Heavy (Double E.H.) which is commonly used where high pressure exists.
Pipe Diameter:
All pipe referred to in the informative session is outside diameter (O. D.)
controlled. Up to 12 inches in diameter, standard pipe is referred to as its
nominal inside diameter. This measurement is not the exact inside diameter,
however. For example, in one inch (nominal) standard weight pipe the inside
diameter and outside diameter are 1.049 and 1.315 inches respectively. These
dimensions are subject to plus or minus tolerances. In our industry pipe is
measured by inside diameter based on schedule 40 pipe.
Pipe over 12 inches is known by its actual outside diameter and wall thickness.
So, a 16-inch outside diameter pipe would have an outside diameter of 16
inches. The wall thickness could range from 0.250 to 1.593 inches.
Pipe Joining
There are several ways to join steel pipe together. Some of the techniques are
listed below:
Technique
Considerations
Mechanical Coupling - a groove cut
or rolled into the end of the pipe. Pipe
is placed end to end and held together
by a mated coupling.
Anyone can do it
Fast
Maximum cost effectiveness on pipe
sizes 2-1/2" to 6" due to coupling cost
Greatly reduces replacement time for
sections of pipe
Welding - 37 1/2 degree bevel cut or
ground on end of pipe. Pipe placed end
to end then welded together.
Requires a certified welder
Time consuming and labor intensive
Does not require couplings so it is
more economical on a large scale
More permanent, stronger joint
Less chance of leaking
Pipe Threading - Male threads are
located on the pipe end and female
threads are in the coupling.
Anyone can do it
Fast
Couplings from 1/2" to 2" are
inexpensive
Pipe Dies:
What is a pipe die?
A pipe die is the threading tool that actually cuts external threads on the pipe.
Pipe dies are sometimes referred to as chasers, cutters, segments or teeth. The
dies are made from either alloy or high speed steel. There are many variations of
dies to accommodate the complete line of threading. Typically, pipe dies or
threaders can be classified different ways:
Manual Threaders – R12+, R11 or Solid Die Series are typically size specific.
All dies are secured in a drophead or a die stock with the use of a ratchet ring
while the pipe is threaded by hand.
Power Driven – R12+ or R11 dropheads mounted into a portable power drive,
supported with a power drive vise. The dropheads are turned onto the pipe to
create the thread.
Also, dies that are specific to the threads per inch can be adjusted to the size of
the pipe needing threading. The universal dies are mounted in an R811 head and
the head is adjusted for the specific pipe size. The head is then mounted into the
carriage of the power driven machine and used to thread pipe.
Pipe Die Materials:
Alloy Dies:
A. Most popular for threading with hand threaders
B. Shorter useful life span
High Speed Dies:
A. Used where continuous threading is being performed typically by
power threading machines
B. Longer useful life span
C. Recommended when threading on any power threading machine
D. Made from high speed tool steel which is better suited to handle the
additional heat and friction created by the speed of the machine
Pipe Die Applications:
Black steel pipe
Plastic pipe
Low carbon steel
Galvanized steel pipe
Plastic coated conduit
Medium carbon (Rc-30)
Stainless steel pipe
Bolt stock
Stainless
There are over 350 different types and sizes of dies manufactured today. Some
dies are designed specifically for hand threading applications while others are
used in machine die heads.
Dies for stainless steel and plastic are different than the die sets used for
standard black or galvanized pipe. The changes made to these dies to
accommodate the different materials are very critical and cannot be seen without
a trained eye, therefore, always identify these special dies for the material they
are intended to thread. Dies with no special identification are intended for black
and galvanized pipe. These are by far the most common dies used in the field.
Die Types
Full Width Dies:
A. The width of the die is equal to the length of the thread to be cut
B. It is the most common die used
C. When threading with a full width die, the force required to thread
becomes greater as the die advances
D. When cutting tapered threads each following tooth cuts deeper to
produce the taper form until the desired thread length is produced
E. Examples of full width dies are: 12R, R12+, SD Series, Universal, Mono
and Dual
Receding Dies
A. The width is less than the thread to be cut
B. Normally these dies have only one full tooth
C. When threading with a receding die, the force required to thread
becomes less as the die advances
D. When cutting a taper thread, the form is produced by the die moving
radially from the axis of the pipe within the die head
E. Examples of receding dies are: 65RC, 4PJ, and 141/161 geared
threaders
Solid Dies
A. Block dies are mounted in a die stock for manual threading. No setting
of die segments in a head are required.
B. Cast iron block with the steel inserts are machined and heat treated.
Threaders
A. Power Threaders
Users include mechanical contractors, industrial maintenance persons,
waterworks professionals and others who need to thread and hot tap
pipe. Power threaders are portable and can be used at the worksite.
Some in-place threading can be preformed with portable power drives
as well. Used when a large amount of pipe or large size pipe needs to
be threaded. Power threaders save time and money
B. Hand Threaders
Primarily sold to plumbers, mechanical contractors, industrial
maintenance, gas companies, and refineries. Hand threaders are less
expensive and used when a smaller amount of pipe needs to be
threaded or where electrical power is not available
C. Geared Threaders come in 2 types:
1. Geared Threader - 2 1/2" - 4" pipe capacity, National Pipe Taper
(Mechanical) & National Pipe Straight Mechanical (Electrical)
2. Geared Threader - 4" - 6" pipe capacity, National Pipe Taper
(Mechanical) & National Pipe Straight Mechanical (Electrical)
Both threaders have the same features the difference is the actual size
and capacity. The geared threaders can be used with a power drive or
manually.
Rolled Grooving
The roll grooving method of joining pipe was first developed in the early 1900's
and used by the military. It was a rapid method of joining pipe and is still used
today. Roll grooving is one of four conventional piping methods. The remaining
methods are: threading, welding, and flanged. Roll grooving is gaining in
popularity every day.
Roll groovers are designed to form standard rolled grooves in steel, stainless
steel and aluminum pipe, from 1-1/4” to 6”, in both Schedule 10 and Schedule
40. Also, roll groovers are designed to groove PVC and aluminum pipe in 2 – 6”
schedule 10, 2 – 3” schedule 40 and copper pipe. The groove is formed by the
groove roll which is fed into the pipe wall. The pipe is supported on the inside by
a drive roll, which is relieved to permit pipe wall deformation. The formed
grooves comply with the specifications required for mechanical coupling systems.
The only adjustment required is for the depth of the groove.
Pipe Preparation in Roll Grooving:
A. Pipe end must be square. Do not use a cutting torch. When
adjusting roll groover depth, the trial groove pipe should not
have a large burr protruding inward. Use a pipe reamer or other
suitable tool to deburr trial groove pipe. After groove depth has
been set, deburring of pipe is not required.
B. Pipe out of roundness must not exceed the total O.D. tolerance
given in groove specifications. To determine out of roundness
measure maximum and minimum O.D. at ninety degrees apart.
Pipe Length:
The chart below lists the minimum length of pipe to be grooved and
maximum length to be grooved without a pipe jack.
Nominal Pipe Size in
Inches
1-1/4
1-1/2
2
2-1/2
3
3-1/2
4
4-1/2
5
6 O.D.
6
Minimum Length in
Inches
8
8
8
8
8
8
8
8
8
10
10
Max. Length in Inches
w/o pipe jack
36
36
36
36
36
36
36
32
32
30
28
Pipes longer than the specified maximum lengths must be supported with a pipe
jack. The pipe jack should be located ¾ of the pipe length from the roll groover.
Long lengths of pipe may require two jacks.
Groove in-place Set-up:
Previously installed piping may be grooved in-place providing the pipe is
securely supported.
NOTE: Pipe hangers must be able to accommodate the weight of the tool
plus the manual effort to operate the roll groover.
WARNING: Piping systems must always be depressurized and drained
before attempting disassembly. Failure to do so could result in serious
injury, property damage, joint leakage or joint separation.
Pipe Set-up:
The roll grooving tool rotates around a pipe that is held stationary. The
pipe may be held in a pipe vise during grooving or grooved in-place.
Pipe Vise Set-up:
The choice of grooving location in the shop or field should take into
account the following factors:
A. Pipe handling requirements
B. Working space requirements for the tool and pipe
C. Anchoring requirements for the pipe vise
Pipe Vise Set-up Procedure:
1. Securely mount pipe vise (chain type) on a secure stand, workbench or
portable pipe vise. Pipe vise should be mounted flush with or overhang
the edge of the stand or workbench so, when the tool is mounted on
the pipe, the tool will rotate freely around the pipe and not be
obstructed by the bench or stand.
2. Secure the pipe in the pipe vise, anchored to hold securely the weight
of the tool. Position the pipe to overhang the pipe vise approximately
5 – 12” so the tool can rotate in an unobstructed manner.
Markets:
HVAC
Chilled Water
Underground Services
A/C Systems
Condenser Water
Pump Dressing
Cooling Tower Piping
Industrial
Storage Tank Piping
Pollution Control Piping
Process Piping
Waste Lines
Chilled Water Lines
Shipbuilding
Bilge Piping
Fire Protection
Sounding Tubes
Cooling Water
Drains & Overflows
Salt Water Piping
Other Markets include:
Chemical Plant Operations
Fire Protection
Paper Mills
Water Plants
Potable Water
Lube Oil Piping
Steel Mills
Mining Operations
Materials that can be rolled grooved include:
Carbon Steel
Stainless Steel
Copper CTS
Aluminum
Schedule 5, 7, 10, 20, 40 grade 52 and 106
Schedule 5, 10, 20, 40 grade 304 and 316
2" through 8" grades K, L, M
Schedule 40, T4 alloys only
There are 3 types of grooves that can be made today: roll groove, straight cut
groove and radius cut groove. Pipe size that can be grooved varies from threequarter inch up to 36 inches.
Styles of Groovers:
There are several styles of groovers available on the market today some of them
include:
Portable
Hydraulic Floor Models
In-place
Portable Hydraulic models
Roll Groover Safety
When operating, keep hands away from the grooving rolls. Fingers could
get caught between the groove roll and drive shaft.
When setting up and using, make sure the roll groover is secured to the
pipe. Carefully follow set up instructions.
Do not use a roll groover for any other purpose than roll grooving pipe
and tubing.
Be sure pipe or tubing is secure in a pipe vise or securely hung in place.
Supporting long lengths of pipe or tubing with a pipe jack.
Always refer to the roll groover manufactures operating instructions for all
safety requirements.
Roll Groover Trouble Shooting
Problem
Unable to close rolls onto
pipe.
Cause
Improper adjustment of
depth stop collars.
Groove to deep (groove
diameter too small).
Groove to shallow
(groove diameter to
large).
Tool does not move
when cranked.
Improper adjustment of
depth stop collar.
Improper adjustment of
depth stop collar
Tool wobbles during
cranking.
Tool won’t track
(walks or falls off pipe).
Solution
Turn depth stop collars
counterclockwise, away
from trunnion and reset
depth stop collar.
Reset depth stop collars.
Reset depth stop collars.
Rust or dirt has built up
on lower roll.
Remove accumulation
from lower roll with stiff
wire brush.
Worn grooving rolls.
Inspect lower roll for
worn knurls, replace if
worn.
Advance the feed at the
proper rate.
Variation in pipe wall
thickness or inadequate
feed rate.
Tool is not correctly
positioned on the pipe.
Pipe end out of square.
Reposition tool with pipe
end stops against pipe.
Trim pipe to square pipe
end. Advance the feed at
the proper rate.
Excessive fall off at pipe
end from use of pipe
cutter with improper feed
rate.
Tool won’t groove
tube/pipe.
Tool crank turned in the
wrong direction.
Turn feed and crank nuts
clockwise.
Tube/pipe beyond tool’s
wall thickness capability.
Review tool specifications
chart.
Tube/pipe material
excessively hard.
Use recommended pipe
material.
Questions to ask your customer to determine what type of
products they require:
1. What type of work is being conducted? Electrical or Mechanical
2. What type of material is being threaded? Schedule 40, stainless steel
etc
3. What are the pipe sizes being threaded? 1/2", 1 1/2" etc
4. What thread form is required? NPT, NPSM etc
5. Do you require a portable or in-place groover?
6. What type of material are you grooving?
Selling Tips
When selling pipe threading tools and accessories made by Evergreen Preferred
Suppliers be sure to emphasize:
1. Quality construction
2. Large selection of accessories
3. Availability of service
Accessories
These are some of the items you may consider offering when you are discussing
pipe threading options with your client:
Wrenches
Cutting Oil
Safety Glasses
Teflon Tape
Gloves
Replacement Dies
Tapping Compound
Pipe Dope
Pipe Jacks
Pipe Stands
Pipe Reamers
Pipe Cutters
General Safety
Serious injury can occur if all safety information is not followed. These injuries
could include, but not limited to:
Loss of fingers, hands or other body parts if clothing gets caught in
moving parts of the equipment
Impact injuries, including broken bones if work piece falls
Always wear eye protection when working with this type of equipment
For more information on pipe threading and roll grooving equipment
visit:
www.reedmfgco.com
Introduction to Pipe Threading and Roll Grooving Questions
Instructions: There is only 1 correct answer to each question. If more than 1
answer seems to be correct, choose the answer that most closely fits the
material covered in the module. When you have completed the exam, detach
the exam pages and fax them to: Evergreen Training Coordinator, 972-242-1411.
Your exam will be scored, the score will be posted to your transcript, and the
results will be sent to you.
You may also take the exam online at
www.evergreen-marketing.com – online exam results are posted to your
transcript automatically.
1. What type of pipe requires “special” pipe tools for threading and cutting:
A. Polyethylene
B. Stainless Steel
C. Commercial Steel Pipe
D. Galvanized Pipe
2. Pipe over 12 inches is known by its _______ outside diameter and wall
thickness:
A. Advertised
B. Nominal
C. Actual
D. Estimated
3. Markets where roll groovers are used include all of the following except:
A. HVAC
B. Shipbuilding
C. Industrial
D. Concrete cutting
4. Of all the ways to join pipe together, which is the most permanent and
provides the strongest joint:
A. Welding
B. Pipe Threading
C. Mechanical Coupling
D. Brazing
5. The ________ Die is the most common die used:
A. Receding
B. Block
C. Full Width
D. Off Set
6. Galvanized pipe is hot dipped and coated with:
A. Titanium
B. Lead
C. Zinc
D. Graphite
7. Pipe over 12 inches is known by its actual _______________ diameter and
___________________.
A. Inside; weight
B. Outside; length
C. Inside: wall thickness
D. Outside; wall thickness
8. Which of the following is not a method used to join pipe together:
A. Welding
B. Pipe Threading
C. Duct Tape
D. Mechanical Coupling
9. The following are good reasons to partner with Evergreen Preferred Suppliers
except:
A. They can assist you in gaining valuable pipe threading and roll
grooving training
B. They can provide excellent technical assistance
C. They offer cash back rewards just like the big credit card companies
D. They have a large selection of accessories that you can offer your
customers
10. Serious injury could occur if all safety information is not followed. These
injuries could include:
A. Impact injuries
B. Loss of fingers, hands or body parts
C. Eye injuries
D. All of the above
11. If your roll grooving tool walks or falls off the pipe, which of the following is
not a possible cause:
A. Tool is not correctly positioned on the pipe
B. Rust or dirt has built up on the lower roll
C. Pipe end is out of square
D. Tool crank is turned in the wrong direction
12. The piece of equipment that actually cuts the external threads on the pipe is
called:
A. Pipe Jack
B. Die
C. Roller
D. Vise
13. Which of the following add-on items should you offer when talking to your
customer about their pipe threading and roll grooving requirements:
A. Replacement dies
B. Pipe dope
C. Gloves
D. All of the above
14. Dies with no special markings are intended for ___________ and
___________ pipe.
A. Stainless; plastic
B. Black; galvanized
C. Medium carbon (Rc-30); low carbon
D. Plastic; black
15. Which of the following pipe joining techniques is the most time consuming
and labor intensive?
A. Welding
B. Pipe threading
C. Mechanical coupling
D. Gluing
16. Which of the following is not a full width die:
A. R12+
B. Universal
C. 65RC
D. 12R
17. When preparing to roll groove an installed piping system you should depressurize the system prior to beginning:
A. True
B. False
18. Galvanized pipe is more resistant to:
A. Leakage
B. Corrosion
C. Electrical conductivity
D. Discoloration
19. Which of the following is not a method to join copper piping:
A. Grooving
B. Soldering
C. Welding
D. Flaring
20. In pipe threading the male threads are located in the coupling:
A. True
B. False
21. There are over_____ types and sizes of pipe dies manufactured today:
A. 450
B. 275
C. 200
D. 350
22. When threading with a receding die, the force required to thread becomes
________ as the die advances:
A. Less
B. Remains the same
C. Greater
D. Fluctuates
23. You can roll groove which of the following types of aluminum:
A. Schedule 5, 7, 40 grade 106
B. Schedule 40, T4 alloys only
C. 2” through 8”
D. Schedule 55
24. Roll grooving was first used by the _______ in the _______:
A. Electrical trades; 1500’s
B. Military; 1900’s
C. Industrial trades; 1900’s
D. Shipbuilder; 1700’s
25. What technique in pipe joining uses a coupling to hold pipe together:
A. Welding
B. Pipe threading
C. Mechanical
D. soldering