Blockage of a critical 5” overflow pipe beneath a large artificial lake at Dospat Dam, Bulgaria, posed extreme danger to dam wall integrity – risking catastrophic failure.

Over 50 years of hardened sediment and debris had accumulated.  Drainage reduced to a trickle.  And construction of a new removal conduit proved unfeasible.

The remote setting also eliminated heavy cleaning equipment from consideration.  And the 460’ line descended over a 2.5% grade from 157 feet beneath the dam wall through four tight bends to its terminus – rendering clean out extremely difficult.

That’s when Double D Engineering Ltd, European specialists in industrial cleaning technologies and services, stepped in – with an “outside the box” idea.

“Economics and facility condition forced us to work with the existing pipeline,”  Dimiter Dimitrov, company manager, noted. “So we opted for a compact, portable water jet solution.”

A Compact, Powerful Solution

Representing the Russian company Zevs Technologies Ltd, Double D chose the powerful, compact, and maneuverable JM-3080 water jet from General Pipe Cleaners.

Part of General’s popular Jet-Set™, the high-flow device is perfect for clearing larger, more difficult lines of grease, sediment, and ice.  A 20 hp Honda engine provides an 8 gpm flow rate at 3000 psi.  A 12 gallon buffer tank provides enhanced safety margins.

“We’ve specialized in industrial cleaning since 1998, and this was our first project with JM-3080,” Dimitrov adds. “We were enormously pleased with its portability, power and performance.”

“The steel overflow line featured four turns over its length,” he notes. “And Vibra-Pulse^® helped ensure thorough removal of the built-up sediment and debris.”

Fresh Approach Yields Results

Partially tapping lake water 130 feet away, Double D cleared the blockage in three steps over roughly 12 hours and three days:

Phase 1.  About 295 feet were cleaned from the lower end of the pipe with all three high-performance nozzles.  Total work time: 5 h 15 min.

Phase 2.  Another 75.5 feet from the lower end were subsequently cleaned with the three high-performance nozzles.  By then, however, the JM-3080 had hit maximum reach.  Total work time: 5 h 30 min.

Phase 3.  Double D then repositioned the JM-3080 to clean 164 feet from the pipeline’s upper end.  Total work time: 1 h 24 min.

Conditions on the final project leg proved especially hazardous.  Personnel had to descend to a gallery about 164 feet below lake water level.  And they risked catastrophic flooding from large chunks of loosened sediment blocking the clean downstream end.  But by employing smaller jet nozzles – and gradually removing the blockage from the center out – workers successfully completed the job.

Sediment and debris blockages plague thousands of dam, waterway and waste treatment pipelines.  But not all are accessible to larger trailer-mounted water jets.  Double D blended innovative techniques with a compact, powerful General water jet for a creative, yet effective solution.

“Everything worked beautifully,” Dimiter Dimitrov concludes. “We could not have achieved those positive results without our JM-3080!”

Learn more about what General’s Jet-Set water jets can do for you, or contact the Drain Brains^® at General at 800-245-6200 or by email [email protected].