Lined Pipe in Chattanooga, TN

Two plants on the Hiwassee River at Charleston, in Bradley County, set the tone for corrosive service around Chattanooga: a membrane-cell chlor-alkali plant making chlorine, caustic soda, potassium hydroxide, bleach, hydrochloric acid and hydrogen, and the polysilicon complex beside it, built for about 2.5 billion dollars on 550 acres, that turns silicon metal and hydrogen chloride into hyperpure silicon. Downriver sit Chattanooga's foundry, graphite and consumer health plants, the Sequoyah nuclear station and, over the Georgia line, the Dalton carpet mills. Marspec Technical Products fabricates the plastic-lined pipe spools and supplies the lined fittings and valves this corridor needs, with spools shipping from Fairhope, Alabama. Call (251) 625-4949.

Send a valve list, a spool drawing or a photo of the failed part and we will quote a replacement, or contact us online.

Charleston: chlorine on one side of the fence, silicon on the other

The chlor-alkali plant replaced its mercury cells with membrane cells in 2012 after a 160-million-dollar rebuild sized for about 200,000 tons, with an emphasis on potassium hydroxide. The cells run on purified brine and produce wet chlorine, caustic that is evaporated to 50 percent, and hydrogen, and part of the chlorine becomes hypochlorite and hydrochloric acid. Wet chlorine, hypochlorite and HCl justify lined pipe more often than any other fluids: PTFE-lined spools, in vented housings because chlorine and HCl permeate the liner, and PFA-lined ball valves carry them without titanium, nickel alloys or rubber linings, and lined plug valves handle brine and caustic.

Next door, the polysilicon plant reacts metallurgical silicon with hydrogen chloride to make trichlorosilane, purifies it and deposits silicon on heated rods, with capacity above 20,000 metric tons a year. The main byproduct, tetrachlorosilane, goes back into the loop or to a 13,000-ton-a-year pyrogenic silica plant started in 2019. Dry chlorosilanes travel in steel, but the moment they meet water they hydrolyze to hydrochloric acid and silica, so the vent scrubbers, caustic scrubbing loops, acid-water collection, HCl absorption and neutralization around every chlorosilane unit are lined-pipe service.

Chattanooga: iron, graphite, batteries and consumer health

Chattanooga's own plants are a collection of corrosive utilities. The iron foundry that casts gate valves and hydrants and the automotive stamping plants run acid pickling, phosphate and zirconium pretreatment, e-coat and caustic cleaning baths with rinse water that must be neutralized. A synthetic graphite plant refitted to produce 20,000 tons a year of battery anode material, backed by a conditional federal loan of about 755 million dollars, brings scrubber and process water chemistry. The consumer health plant, with about 700 full-time employees, and the bakery in Collegedale, with more than 3,000, clean process equipment with nitric and phosphoric acid and hot caustic in CIP loops. The vehicle assembly plant here, which added electric vehicle production in 2022, runs paint-shop pretreatment on a 5,000-employee scale. In Cleveland, an alkaline battery plant that has run since 1964 fills cells with potassium hydroxide electrolyte, the same KOH made a few miles away on the Hiwassee.

Sequoyah, the river plants and the carpet mills over the line

The two pressurized water reactors at Sequoyah, on Chickamauga Lake above Soddy-Daisy, have run since 1981 and 1982 and carry a winter net capacity of 2,440 megawatts. Boric acid, condensate polisher regeneration with sulfuric acid and caustic, hydrazine and demineralized water are the chemistry of a PWR, and hypochlorite treats the river water that cools it. The Citico plant treats Tennessee River water for the city. Moccasin Bend treats an average of about 65 million gallons a day with high-purity-oxygen activated sludge, is rated for 140 million gallons hydraulically, has replaced chlorine gas with sodium hypochlorite and sodium bisulfite, and serves about 400,000 people.

In Dalton, the carpet and flooring mills and the city utility are building PFAS treatment into their water and wastewater systems, which puts activated carbon and ion exchange trains, with their acid, caustic and hypochlorite feeds, next to the mills' own process chemistry. Carpet finishing is dye chemistry, acids and alkalis for pH control, latex and polyurethane backing and hypochlorite, and a specialty surfactant and polymer maker headquartered in Dalton supplies the industry from a plant in Whitfield County. Those dosing and wastewater lines are PTFE or PVDF service, with PTFE on the caustic and full-strength hypochlorite feeds.

What ships to the Chattanooga corridor

• Custom lined spools, 1/2" through 12" and up to 20 ft, PTFE, PVDF or polypropylene lined, carbon steel or 304/316 stainless housings, with matching lined elbows, tees, reducers and laterals
• PFA-lined ball valves and PTFE-lined plug valves for chlorine, HCl, hypochlorite and caustic; lined diaphragm valves for throttled dosing; lined butterfly, check and sampling valves
• Lined strainers, expansion joints, PTFE spacers and spectacle blinds, sight glasses and solid PTFE pipe
• Clamp-on steam heaters, electric tracing and heat-transfer compound for 50 percent caustic and potassium hydroxide lines that crystallize in a cold snap

Match the liner to the fluid: PTFE for wet chlorine, HCl, chlorosilane scrubber effluent, caustic, brine, hypochlorite and neutralized wastewater, PVDF for dilute or lower-pH hypochlorite and high-purity water, and polypropylene for the dilute caustic and brine lines where a specification calls for it. Our lined pipe and fittings comply with ASTM F1545, fittings conform dimensionally to ANSI B16.5 and are welded to ASME B31.3 by welders certified to ASME Section IX, and every lined pipe spool and fitting passes a spark test at a minimum of 10,000 volts. Liner ratings are on the technical details page, backed by more than half a century in plastic-lined piping.

Chattanooga, Cleveland, Charleston and Dalton

We serve Chattanooga, Cleveland, Charleston, Athens, Soddy-Daisy, Collegedale, South Pittsburg, Dalton, Calhoun, Rome and Fort Oglethorpe from Fairhope, Alabama. Call (251) 625-4949 or contact us online with your spool package or valve list.

FAQ: Lined Pipe in Chattanooga, TN

Which lined valves fit the chlorine, caustic and bleach streams at a Bradley County chlor-alkali plant?

PFA-lined ball valves for wet chlorine and hypochlorite isolation, PTFE-lined plug valves for 50 percent caustic and potassium hydroxide, and lined diaphragm valves for throttled bleach dosing. All are flanged to the same standard as our lined spools so the run is consistent from the cell room to the loading rack.

Where does lined pipe belong at the Charleston polysilicon site if the chlorosilanes run in steel?

Everywhere the chlorosilanes meet water: vent and emergency scrubbers, caustic scrubbing loops, HCl absorption, acid-water collection and neutralization. Hydrolysis produces hydrochloric acid, and PTFE-lined spools in vented housings and PFA-lined valves handle it in any concentration.

Can you supply PVDF-lined spools for sodium hypochlorite at Moccasin Bend or the Citico plant?

Yes, for dilute or lower-pH hypochlorite. PTFE-lined spools with lined diaphragm and ball valves are our recommendation for full-strength hypochlorite feed, since commercial 12.5 percent bleach carries excess caustic at about pH 12 to 13 that attacks PVDF over time, and PVDF or PTFE suits the bisulfite dechlorination and coagulant lines; the liner keeps metal ions out of the bleach and holds up to the chlorinated water that attacks stainless.

Do you build lined spools for the Dalton carpet mills and their chemical suppliers?

We do. Dye, latex, surfactant and pH-control chemistry runs well in PTFE- or PVDF-lined spools, with PTFE on strong caustic, and PFA-lined ball valves handle the hypochlorite. Send the fluid list and line sizes and we will quote a package, with spools and valves shipping from Fairhope.