LB Industrial Systems - Innovation by Design Positive Seal Ash Transfer Piping System
Positive Seal Ash Transfer Piping System

The use of cast alloy pipe and compression-type joints for fly ash conveying lines has been an accepted industry practice for decades. Specifications routinely reference these materials. Spare parts are readily available from OEM’s inventories. Maintenance personnel are very familiar with the systems, and “conventional wisdom” holds that since ash is abrasive, elbows and fittings wear out, and that leaks are an unavoidable flaw of pneumatic systems. (Some specifications for this material even call for allowances in conveying rates of up to 10% for ash pipeline leakage.) As a consequence, plants commonly factor in a loss of efficiency, higher operating energy costs, high costs for spares and higher than necessary maintenance labor costs.

Leaks in vacuum ash transport pipes cause a deterioration in performance. Leaks in pressure ash transport pipes cause dust emissions. Leaks most frequently result from the use of sleeve type couplings and locking ring clamp flanges. The couplings can be tightened up with the unit offline; but, as soon as the unit starts up, all the piping moves, leaks restart and couplings have to be re-tightened. The longer the vacuum line; the greater the deterioration in performance.

A proven alternative piping technology is available and is saving power producers energy, spare parts and maintenance costs at a growing number of installations
LB’s ash conveying pipelines incorporate flanged and gasketed fittings. All piping movement is taken up in properly designed expansion joints. And, we provide a five year wear warranty on the key components.

The standard LB piping configuration utilizes cast Nihard 4 fittings with a hardness of 550 Brinnell. Each fitting is followed by a 3’ downstream tail piece of induction hardened steel pipe with a hardness of 600 Brinnell.
All other straight runs of piping are schedule 40 carbon steel. The tail piece and straight runs of pipe utilize welded flanges. The Nihard 4 fittings utilize split ring clamp flanges. All joints are gasketed.





Ash conveying pipeline expansion primarily results from thermal stresses due to ash temperature. Expansion joints are installed where necessary based on a thermal and structural analysis of the final configuration. The use of expansion joints is avoided where possible by judicious location of anchor points and the allowance of free movement at turns.

The success of this simple design approach is based on the science of material behavior in pneumatic transfer pipelines. Particles of fly ash act in certain predictable ways as they are conveyed through a piping system. LB has applied the science of pneumatic material transfer to design out the sources of system failures.

Because of LB’s extensive system retrofit experience, we have been called on many times to remedy the inherent flaws in other providers’ systems. By strengthening the component parts only where needed, the system cost and reliability is optimized. By providing flanged, bolted and gasketed joints for a positive pressure or vacuum seal, the energy cost to produce motive air is optimized. “No leaks” means a cleaner operating environment in the plant. Ash moves where it’s intended to go, with less energy and fewer headaches.

The LB “Positive Seal” Piping system can be seen in operation at the following U.S. plant locations. Detailed information and reference contact information is available on request.



Customer Plant Unit Location Type Length Rate Remarks
Georgia Power Bowen 3&4 Stilesboro, GA Vacuum 550'/10" dia 45 TPH In operation since 2001
Georgia Power Bowen 1&2 Stilesboro, GA Vacuum 450'/10" dia 45 TPH In operation since 2001
Georgia Power Bowen 1,2,3&4 Stilesboro, GA Pressure 5500'/10, 12 & 14" dia 200 TPH In operation since 2001
Georgia Power Bowen 1,2,3&4 Stilesboro, GA Pressure 5150'/10, 12 & 14" dia 200 TPH Start-up Completed 2012
Georgia Power Bowen 1,2,3&4 Stilesboro, GA Pressure 3962'/10, 12 & 14" dia 200 TPH Start-up Completed 2012
Georgia Power Branch 3&4 Milledgeville, GA Vacuum 650'/8 and 10" dia 30 TPH In operation since 2000
GDF Suez NA Coleto Creek 1 Fannin, TX Vacuum 415'/8 10 & 12" dia 35 TPH In operation since 2006
GDF Suez NA Coleto Creek 1 Fannin, TX Pressure 3736'/6 8 & 10" dia 70 TPH In operation since 1994
SCE&G Canadys 3 Canadys, SC Vacuum 280'/7 & 10" dia 46 TPH In operation since 2008
SCE&G Canadys 3 Canadys, SC Pressure 521'/8 & 10" dia 46 TPH In operation since 2008
Alabama Power Gadsden 1&2 Gadsden, AL Vacuum 310'/6" dia 22 TPH In operation since 2005
MRT Labadie 1 Labadie, MO Pressure 1029'/8 & 10" dia 75 TPH In operation since 2006
Alabama Power Miller 1,2,3 & 4 Bermingham, AL Pressure 1029'/8 & 10" dia 75 TPH In operation since 2006
TXU Montecello 1&2 Montecello, TX Pressure 2100'/10 & 12" dia 75 TPH In operation since 2004
IP&L Petersburg 1 Petersburg, IN Vacuum 164'/8" dia 20 TPH In operation since 2007
IP&L Petersburg 2 Petersburg, IN Vacuum 225'/8" dia 30 TPH In operation since 2007
IP&L Petersburg 1&2 Petersburg, IN Pressure 4039'/8 10 & 12" dia 60 TPH In operation since 2007
Progress Energy Robinson 1 Robinson, NC Vacuum 318'/5 8 & 10" dia 25 TPH In operation since 2008
Progress Energy Robinson 1 Robinson, NC Pressure 2558'/8 10 & 12" dia 25 TPH In operation since 2008
Georgia Power Scherer 1&2 Juliette, GA Pressure 665'/8" dia 30 TPH In operation since 2007
Georgia Power Scherer 1&2 Juliette, GA Pressure 1800'/8, 10 & 12" dia 100 TPH In operation since 2005
Georgia Power Scherer 3&4 Juliette, GA Vacuum 375'/8"" dia 25 TPH In operation since 1999
Georgia Power Scherer 3&4 Juliette, GA Pressure 716'/8 & 10" dia 100 TPH In operation since 1999
Georgia Power Watson 4 (5A & 5B Sim.) Gulfport, MS Pressure 1431'/8 10 & 12" dia 66 TPH In operation since 2002
Georgia Power Watson 4&5 Gulfport, MS Pressure 1431'/8 10 & 12" dia 66 TPH In operation since 2002