 |
The following
are some frequently asked questions regarding the PETROSLEEVE®
Pipeline Repair System. Contact PETROSLEEVE® should
you require any additional information. |
How does the PETROSLEEVE® work?
Where has the PETROSLEEVE® been used?
To date, how many installations of the PETROSLEEVE®
are there worldwide?
What type of pipeline service can the PETROSLEEVE®
be installed on?
Does the reinforcing action of the PETROSLEEVE®
extend past the edge of the sleeve?
What testing was performed on the PETROSLEEVE®?
What long term testing was undertaken?
What is the maximum internal pipe pressure that
can be repaired by a PETROSLEEVE®?
Is the PETROSLEEVE® patented?
Will the Installation of a PETROSLEEVE® affect
internal line inspection?
When installing a PETROSLEEVE®, what engineering
analysis is available?
After a PETROSLEEVE® is installed, how can the
final stress condition surrounding the defect be determined?
What type of defects can be repaired?
What type of defects can not be repaired by the PETROSLEEVE®?
Has any testing been performed to confirm that cracks
do not grow?
Will the PETROSLEEVE® be resistant to corrosion
attack after it is installed on the pipe?
How is a long defect repaired?
Can a PETROSLEEVE® be installed on out-of-round
pipe?
What is the working time for the epoxy?
How long does it take to install a PETROSLEEVE®?
What is the life span of a PETROSLEEVE® installation?
What type of coating is used on the PETROSLEEVE®?
What is the regulatory acceptance of the PETROSLEEVE®?
When can I coat and backfill a PETROSLEEVE® after
it is installed?
Do I need any hoisting equipment during installation
of a PETROSLEEVE®?
How does the PETROSLEEVE® work?
The PETROSLEEVE® performs by supporting and reducing the stress in the
steel adjoining the defect such that the defect is arrested from growing
or deteriorating.
top of page
Where has the PETROSLEEVE® been used?
The PETROSLEEVE® is installed
in USA, Canada, Mexico, Dominican Republic, and Australia.
top of page
To date, how many PETROSLEEVE® installations
are there worldwide?
Over 6500 PETROSLEEVE® installations
are successfully installed to date.
top of page
What type of pipeline service can the PETROSLEEVE®
be installed on?
The PETROSLEEVE® can repair
defects on any type of pipeline. Sleeves are installed on pipelines
transporting natural gas, sour
gas, crude oil, high vapor liquids, condensate, propane, butane, and
ethane liquids.
top of page
Does the reinforcing action of the PETROSLEEVE® extend past the edge of the sleeve?
Testing and finite element analysis illustrates that the reinforcing
action on the PETROSLEEVE® extends
approximately 2 inches past the edge of the sleeve. Consequently,
when the sleeves are installed
within 1 1/2 inches of each other, the reinforcing forces developed
by the two sleeves act to restrain the bare pipe between the
two
edges.
top of page
What testing was performed on the PETROSLEEVE®?
Extensive testing - includes severe cyclic pressure testing for
cracks and severe corrosion defects, strain gauging, collapse testing,
and
long term testing. Complete strain gauge analysis has confirms FEA
model development.
top of page
What long term testing was undertaken?
PETROSLEEVE® installations
over stress corrosion cracking and corrosion defects were removed
after being exposed to extended severe field
conditions. When the sleeves were removed, the pipe surface where the
epoxy had been sheared by the removal process appeared bright and
clean,
similar to a newly sandblasted surface.
top of page
What is the maximum internal pipe pressure
that can be repaired by a PETROSLEEVE®?
In most circumstances, there are no pressure limits for PETROSLEEVE® installation and operation. However, based on the severity of the
defect being
repaired, pressure may be reduced during installation to ensure optimal
safety conditions.
top of page
Is the PETROSLEEVE® patented?
Yes, the PETROSLEEVE® Repair
System and installation design is a patented process.
top of page
Will the Installation of a PETROSLEEVE® affect
internal line inspection?
After a PETROSLEEVE® is installed, any magnetic flux leakage
inspection tool will identify the sleeve. Ultrasonic inspection tools
will not identity the sleeve, but will identify the repaired defect.
top of page
When installing a PETROSLEEVE®, what engineering
analysis is available?
Prior to installing a PETROSLEEVE®,
the EIP (Engineering Installation Parameters) Software is utilized
to determine the sleeve design and
installation parameters.
The sleeve/pipe/defect assembly is designed to arrest the growth or
deterioration of the defect.
top of page
After a PETROSLEEVE® is installed, how
can the final stress condition surrounding the defect be determined?
Part of the installation procedure is to perform and follow quality
control procedures. The information obtained in this process is input
into the complimentary EIP (Engineering Installation Parameters) computer
software program. The EIP software then calculates the stress level
in the steel
under
the
PETROSLEEVE®,
and
as determines the stress intensity at the crack tip (in the case
of a
stress concentrating defect).
top of page
What type of defects can be repaired?
The PETROSLEEVE® repairs
defects such as Seam or Pipe Body Cracking, Corrosion, Dents, Mechanical
Defects, SCC (Stress Corrosion Cracking), and Arc Burns. Although the
failure mechanism varies for each defect type, the following is a good
outline description of various defects and how the installation of
a PETROSLEEVE® permanently
removes the failure mechanism of the defect.
1. Corrosion:
Corrosion
defects are caused by a chemical reduction action on the surface of
the pipe material, resulting in localized thinning of the pipe wall.
Failure occurs first by bulging (yielding) at the corrosion site, followed
by rupture of the steel membrane.
The installation of a PETROSLEEVE® provides
mechanical support to the localized thinned section. It is this support that
prevents bulging for all pressures, including during high pressure testing.
top of page
2. Gouge, Groove or Arc Burns:
 These
defects are caused by either third-party damage or non-acceptable workmanship,
and may include stress concentrators such as cracking. Failure occurs
by the pipe material containing the defect flexing because of internal
pressure variances, which in turn causes cracking. When the crack extensions
become critical, rupture occurs.
The installation of a PETROSLEEVE® eliminates
flexing in the pipe material and the stress state in the material surrounding
the defect is put into compression, eliminating fatigue, crack extension, and
rupture.
top of page
3. Dent:
Dent defects are caused by either third party damage or non-acceptable
workmanship. As in the gouge, groove or arc burn cases, failure occurs
by the pipe material containing the defect flexing because of internal
pressure variances, which in turn causes cracking. When the crack extensions
become critical, rupture occurs.
The installation of a PETROSLEEVE® eliminates
flexing in the pipe material and places the pipe material into compression, eliminating
fatigue, crack extension, and rupture.
top of page
4. Pipe Body Crack:
Pipe
Body Cracking is caused by various means, including chemical action
(Stress Corrosion Cracking). Failure occurs when crack becomes unstable.
The installation of a PETROSLEEVE® permanently
reduces the stress state in the material surrounding the defect, removing the
possibility for crack extension.
top of page
5. Weld Defect:
Weld
defects are caused by poor workmanship. Failure occurs when the strength
of the weld is not sufficient to counteract the applied forces.
The installation of a PETROSLEEVE® permanently
reduces the stress state in the material surrounding the defect, as well as providing
support to the weld.
The PETROSLEEVE® provides permanent
mechanical support to the weld area and reduces the strain induced in the weld
by the external forces.
top of page
6. Grind Defect:
A
grind defect is caused by mechanically removing metal from the surface
of the pipe material, resulting in localized thinning of the pipe wall.
In addition, stress concentrators could be present on the metal surface.
Failure occurs first by bulging (yielding) at the grinding area, followed
by rupture of the steel membrane. Additionally, the presence of stress
concentrators could act as initiation points for rupture at lower strain
levels.
The installation of a PETROSLEEVE® prevents
bulging by permanently providing mechanical support to the localized thinned
section. The sleeve also eliminates metal movement (fatigue), and reduces the
strain induced in the material by the external forces.
top of page
7. Leak
A
leak occurs when a hole in the pipe wall allows the liquid or pipeline
product (i.e. oil or gas) to escape, while the pipe wall continues
to contain the internal pressure preventing a rupture from occurring. Both
leaking defects and active internal corrosion will proceed through
the the wall of the pipeline if left unrepaired.
At present, development is underway to research and test a unique
technique using the PETROSLEEVE® Repair
System to repair both leaking defects and active internal corrosion.
top of page
What type of defects can not be repaired by the
PETROSLEEVE®?
At this time, the PETROSLEEVE® it
is not recommended for leaking defects.
top of page
Has any testing been performed to confirm that
cracks do not grow?
Significant cyclic pressure testing was performed in an attempt
to cause fatigue cracking to extend. After 35,600 severe pressure cycles,
no evidence of crack extension was identified.
top of page
Will the PETROSLEEVE® be resistant to corrosion
attack after it is installed on the pipe?
Because of the compression forces between the PETROSLEEVE® and
the pipe, electrical contact exists between the pipe and sleeve. The
cathodic protection impressed upon the pipeline will protects sleeve
steel.
top of page
How is a long defect repaired?
When a defect is longer than a sleeve, multiple sleeves are installed.
The sleeve edges are butted to
each other, not welded.
top of page
Can a PETROSLEEVE® be installed on out
of round pipe?
The PETROSLEEVE® was installed
on many "out of round" pipes.
In all cases, the installation method resulted in a compression fit
with no installation difficulties with out of roundness.
top of page
What is the working time for the epoxy?
The epoxy has a pot life of approximately 30 minutes.
top of page
How long does it take to install a PETROSLEEVE®?
It takes approximately 1 hour to install a PETROSLEEVE®.
top of page
What is the life span of a PETROSLEEVE®
installation?
When the PETROSLEEVE® Repair
System is used for a pipe defect, the installation provides additional
integrity to the pipe, equivalent to a heavy
wall section of pipe. When the installation is complete,
the compression forces between the sleeve and pipe are established,
the excess epoxy is extruded from between the pipe and sleeve,
and the remaining epoxy continues
to
cure.
Because the sleeve is composed of steel, the impressed cathodic protection
used to protect the pipeline also protects the PETROSLEEVE®. Also,
with the epoxy being shielded from ultraviolet rays, the epoxy life
will match that of the PETROSLEEVE® steel itself.
top of page
What type of coating is used on the PETROSLEEVE®?
Any coating suitable for coating pipe can be used on a PETROSLEEVE®.
top of page
What is the regulatory acceptance of the PETROSLEEVE®?
Clause 195.416(f), Federal Register, Vol. 64, No. 239, states that
a repair method shall repair the pipe "by a method that reliable
engineering tests and analysis show can permanently restore the serviceability
of
the pipe". All the completed engineering testing and analysis
shows that by reducing the stress level in the defect region below
a threshold
level effectively arrests defect growth or defect deterioration.
The current Canadian Code accepts the PETROSLEEVE® for corrosion and stress concentrating type
defects. In the June of 2003 edition of Z662, the Canadian Standards Association (CSA) recognized the “Steel Compression Reinforcement Sleeve” repair method. With the PETROSLEEVE® meeting and exceeding the Z662 standard criteria, the Oil & Gas Industry can permanently repair their pipelines. Prior to the recent June 2003 Z662 code issue, the only acceptable method to repair stress concentration type defects (i.e. cracking) was by grinding, welding on a pressure-containing sleeve, or cutting out the defect. The PETROSLEEVE® Repair System offers pipeline owners an incredibly cost effective, safe, reliable and proven alternative! for more, Link to our PRESS page, or, download PETRO-NEWS.
top of page
When can I coat and backfill a PETROSLEEVE®
after it is installed?
Coating and backfill can be completed immediately after installation.
top of page
Do I need any hoisting equipment during installation
of a PETROSLEEVE®?
Installation of 24" sleeves or smaller can be installed
without any hoisting equipment. All installation tools and products
are easily managed by hand. Larger diameters (> 30") require
some form of hoisting equipment.
top of page
© 1997-2005 PETROSLEEVE Inc.,
All rights reserved.
Reproduction in whole or in part in any form or medium without the express
written permission of PETROSLEEVE Inc. is prohibited. design:swur.com |
|