CBU-WSE-2004-00137
Track #: 10080
Disposal Authority: DOE/ADM 17.32a
Retention: Until item is
removed from
service
August 4, 2004
TO:
M. S. Miller, 704-S
FROM: J. T. Gee, 704-25S
SUBJECT:
Demonstration of Citadel Technologies Diamond WrapTM Pipe Repair System (U)
At the request of DWPF, SRS Radiological Operations and Support Center (ROSC) and
Procurement & Materials Management sponsored a pipe repair demonstration using Citadel
Technologies “Diamond Wrap™” System. The demonstration was held on July 12 in 315-M and
was well attended with engineering and maintenance personnel from across the site. Citadel
Technologies was represented by Mr. Roger Walker (Executive Manager) and Mr. Jeff Wilson
(Research Associate at The University of Tulsa). Robbie Bates of ROSC was the primary
interface with Citadel Technologies and his efforts, in setting up the demonstration are strongly
appreciated.
Diamond Wrap™ pipe repair systems provide a structural carbon/epoxy composite system with a
bidirectional weave of 100% carbon filaments providing structural strength. Several variations of
the Diamond Wrap™ repair system have been developed for standard, acid and high temperature
(350o F maximum) service. This material reportedly can contain pressures of several thousand
psig, depending on the degree of surface preparation and the size of hole (or defect) being
contained. The repair wrap is applied in the oil and gas industry to repair pipe and pipelines.
To support the pipe repair demonstration, DWPF maintenance personnel had previously
fabricated three piping assemblies, containing; an elbow (4” diameter, CS), a tee (3” diameter,
CS) and a straight pipe section (6” diameter, SS). Each of the assemblies contained a drilled ¼”
diameter hole to simulate a leak site and were fabricated suitable for hydrostatic leak tests after
the repair had been completed. (Roger Walker had mentioned that this material could have
repaired a 1-1/4” diameter hole, as it has been used successfully to repair bullet holes in pipelines
in Iraq.)
Prior to the pipe repair demonstration, Mr. Walker provided an overview of the Diamond Wrap ™
pipe repair systems. Mr. Wilson followed this presentation with results of some of the research
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work to qualify this material for reinforcement of thinned natural gas pipe lines. The presentations
were followed by a lengthy series of questions about possible applications for these products at
SRS. Mr. Walker indicated that this type of repair would be suitable for both low pressure (100150 psig) steam and steam condensate. It was noted that while repairs can be made to on-line
systems with their wrap products, the active leak must be stopped. Citadel Technologies has
developed low profile metal clamps that can be used to stop the leak and then be incased under
the Diamond Wrap™ material. Mr. Walker indicated that Citadel Technologies normally provides
upfront technical support/evaluation for specific pipe repair inquiries. He did state, when asked,
that it would be possible to obtain kits to have on hand (1-year shelf life) for routine pipe repairs.
During the pipe repair demonstration, Mr. Walker and Mr. Wilson wrapped the portion of the three
assemblies containing the hole. This consisted of a preliminary surface treatment (2-part epoxy)
of the pipe area to be wrapped, working of the 2-part epoxy resin into the carbon fiber patch, and
finally wrapping of the patch. The most difficult patch to apply was that used on the tee section,
as the material had to be cut and molded around the tee. All three assemblies had been repaired
in about 45 minutes. Robbie Bates (ROSC) produced a video of the actual field pipe repair
demonstration and provided a copy for our use.
Following the demonstration, Mr. Walker and Mr. Wilson were available for follow-up questions
and discussions. Mr. Walker agreed to send multiple copies of CDs containing technical
information on Diamond WrapTM pipe repair systems. The CD would also contain a short
installation video demonstrating the repairs.
Hydrostatic Leak Tests:
Hydrostatic leak testing on the three test assemblies was completed in DWPF on 7/2/04. Each of
the repaired assemblies was pressure tested at 425 psig. All of the repair wraps were leak free
and there was no evidence of bulging.
Use of Diamond Wrap™ Repair Technology in ASME B31.3 Piping Systems:
Composite wrap pipe repair methods are not currently addressed in ASME B31.3. A general
repair standard is currently under development by ASME, and composite wrap repairs are one of
the repair methods listed in the draft standard. The site Piping and Valves Committee (P&VC) is
currently in the process of revising our Engineering Standard 15060 (Revision 14) to
acknowledge the use of composite wrap repairs. In addition, P&VC will be issuing a new revision
to the Engineering Guide 15060 which will include guidance on pipe repairs, including composite
wraps. Until these documents are issued, DWPF can still consider the composite pipe repair
systems to be “unlisted components” which are addressed in B31.3. This requires the user to
have supporting documentation to demonstrate the composite wrap repair will contain a pressure
with a 3x safety factor (i.e., required for B31.3). The supporting documentation can be either
generated internally through testing or based on relevant vendor documentation.
Possible Approach for Using Composite Wrap Repairs within DWPF Piping Systems:
Temporary Modifications should not be required to install composite wrap repairs. The noted
ASME draft repair standard does not consider any of the repairs to be “temporary.” This
document will state that all repairs should have a documented design life. (This same logic has
been incorporated into a proposed addition to the site 15060 Engineering Guide to address
repairs to inservice piping system.) In regard to DWPF piping systems, it will be recommended
that for critical repairs, where failure of the piping is unacceptable, the design life of the repair
should be established and tracked in Passport (or STAR). At the end of the designated life, the
repair should be replaced or evaluated to determine possible life extension. In non-critical service,
in which the consequence of failure of the repair is tolerable to operations, the repair could be
designated by the Design Authority as “run to failure.”
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Installation of composite wrap pipe repairs to restore piping integrity should not require a DCF. In
most cases for small bore piping, the only available design document is the P&ID which is not
detailed in regard to specific piping components. Engineering guidance allowing use of these
repairs would better be placed in the DWPF Piping Specifications (T-ESR-S-00010) manual. This
will include a technical review to ensure that any composite wrap repair technique that is
approved will be compatible with piping system.
Implementation Plans for Citadel Technologies Diamond Wrap™ Pipe Repair System:
DWPF Engineering will sponsor “supporting calculations” to demonstrate that the Citadel
Technologies Diamond Wrap™ Pipe Repair System meets the requirements of B31.3 in regard to
“unlisted components.” This calculation will also cover composite repairs based on fiberglass
cloth impregnated with urethane resins. George Antaki, Chairman of the (ESB) Piping and Valves
Committee, is supportive of implementing the use of composite wrap repairs and has offered to
act as verifier (and reviewer) of the calculation. Completion of this calculation should provide a
technical basis to allow the use of composite wraps within other SRS facilities.
Possible applications for these products at DWPF are varied. One attractive area is repair of
steam condensate leaks which are currently being performed by TEAM Industrial using
mechanical clamps (about $2,000 per repair). DWPF could train and certify our people to do the
repairs using these methods, with external costs of between $20-200 per repair for materials. The
alternative fiberglass composite wrap products (e.g., Syntho-Glass®, InduMar Stop It®) look very
attractive for water and possibly steam condensate as these products are water tolerant. The
Diamond Wrap™ repairs have more chemical resistance and can be used at higher
temperatures. The Diamond Wrap™ composite material may be more erosion resistant than
fiberglass, which would be better for the steam condensate systems. Radiation resistance data
on these products is not available at this time, an item that should be pursued later.