VOL 4 | FALL 2014
Technical Talk is an opt-in,
technical publication from
American Polywater Corporation
issued on an irregular basis.
Technical Talk presents original
product and applications research
in the general area of electrical
and utility construction.
» VISIT OUR WEBSITE
» VIEW PAST ISSUES
» SIGN-UP FOR TECH TALK
» CONTACT US
» FOLLOW US ON TWITTER
» LIKE US ON FACEBOOK
Stop Oil Leaks for Improved
Electrical System Reliability
TECHNICAL TALK | volume 4 | page 1 of 4
Transformer leaks are caused by poor welding, vibration, lightning, bullets, animals, rust, vehicles, environmental
conditions, forklifts, wear and tear, and the improper installation of components.
Leaks can occur anytime and can be located at bushings, flanges, threads, gauges, covers, plates, boxes, welds,
potheads, underground lead splices, connections and--most common--radiator fins.
Oil leaks, SF6 gas leaks, and oil containment are major issues for electrical utilities and large industrials. All transformers
on poles, pads, and at substations are susceptible to water ingress, which can cause failure. Underground network
protectors and lead cable splices can also leak, and thus require moisture protection.
Sweeping local, state and federal regulations make protecting the environment from oil and chemical spills a major
priority, especially near bodies of water and population centers.
What happens to transformers if they have a void?
Why repair them now?
There are two major areas of concern in transformer leak repair. The first is how to keep water from entering the
transformer. The longer the delay to repair or patch a transformer, the greater the chance that water enters, leading to
outage or catastrophic failure.
Moisture accelerates the degradation process of paper insulation; increases the risk of thermal breakdown of solid
insulation; and lowers the dielectric strength of both oil and solid insulation.
The second concern is environmental. Leaking oil drips or runs onto the ground and then potentially into groundwater.
Spills near waterways usually require immediate cleanup. Such cleanups are an expensive process.
Local, state and federal regulations on oil spills must be followed. The solution to costly regulatory problems and service
disruptions lies in prompt leak repairs and quick spill response.
What is the best way to fix a transformer in the field?
Some utilities simply replace leaky transformers without even trying to fix them. Why?
Replacing an old transformer with a new one may solve the problem, but it’s a costly operation that causes short-term
electrical service disruption for customers.
Some utilities are simply unaware that an easy method to fix transformers in the field without taking them out of service
even exists.
TECHNICAL TALK | volume 4 | page 2 of 4
The Solution
American Polywater’s unique PowerPatch® Sealant quickly and inexpensively stops active leaks in the field without
special tools or extensive training—and without the need to de-energize the transformer.
View a short video on how FST™ can stop 1 gallon/minute of water running through a conduit:
Installation Video
PowerPatch® Sealant is formulated to provide excellent adhesion to a broad range of metals, rubbers, plastics and
ceramics. It’s impervious to all types of transformer oils and gases; holds high head pressure; contains no metal particles;
and has a high dielectric strength.
Technical Bulletin
PowerPatch® Sealant is formulated to provide excellent adhesion to a broad range of metals, rubbers, plastics and
ceramics. It’s impervious to all types of transformer oils and gases; holds high head pressure; contains no metal particles;
and has a high dielectric strength.
PowerPatch® kits supply all the materials required to seal electrical insulating oil and gas leaks.
The kit’s two-part putty stick is first applied to temporarily
stop an active leak, followed then by overlaying the twopart PowerPatch® Sealant, which is the functioning patch
material that forms a permanent seal due to its superior
adhesion properties. The two-step process forms an
incredibly strong and durable patch.
Kits can be customized to meet end-user requirements.
Many PowerPatch® customers design kits to meet their
system’s specific needs.
Instructions link:
http://www.polywater.com/EPCTInstruction.pdf
Other Uses for PowerPatch®
PowerPatch® is also used to bond metal plates to steel to shore up rusted areas on transformers; repair underground lead
splices; and as an identification marker adhesive for use on polyethylene, fiberglass and steel.
PowerPatch® is very popular with electrical utilities, contractors and transformer companies for fixing all types of SF6 gas
and oil leaks. For examples of successful leak repairs, click on this link.
http://www.polywater.com/EPfieldreports.asp
TECHNICAL TALK | volume 4 | page 3 of 4
I tried an epoxy-like product and it didn’t work!
Why don’t off-the-shelf epoxies work to fix leaks? Epoxy is a broad term that describes an infinitely variable combination
of resin and hardener. Epoxies are very specialized and are formulated with particular performance characteristics on
a narrow range of surface materials for specific applications. Epoxies typically don’t work on applications for which they
weren’t formulated.
Off-the-shelf epoxies are definitely not formulated to stop active leaks in transformers, and most contain metal particles
that assist the chemical reaction or are used as inexpensive filler. These metal particles eventually rust, which can cause
a leak repair to fail.
PowerPatch® is formulated and tested for optimal performance on common transformer surface materials and in contact
with oils and SF6 gas.
PowerPatch® Sealant Review
• Q
UICK PLUGGING ACTION - A fast-cure putty stops oil and SF6 gasleaks.
See 2-Part Paste Application Photos
• PERMANENT SEAL - A 2-part paste overcoat forms a permanent seal.
• DURABLE - Finished seal is impervious to water, oil, and weather.
• FAST - System can plug and seal active leaks in minutes.
• SAVES MONEY - Faster than welding. Transformer may stay in service.
• SIMPLE - Eliminates “bagging” or removal from field.
• C
ONVENIENT - Kit contains all materials needed to fix leak while in the field.
Click here for instructions.
American Polywater | P.O. Box 53 | Stillwater, MN 55082 USA
1-(651) 430-2270 (Voice) | 1-(651) 430-3634 (Fax) | 1-(800) 328-9384 (Toll-Free US/Canada Only)
www.polywater.com | support@polywater.com
TECHNICAL TALK | volume 4 | page 4 of 4