Lined Pipe in Kingsport, TN

Kingsport is a chemical town before it is anything else. The integrated complex on the South Fork of the Holston covers roughly 900 acres of process units inside a 4,000-acre site. Across town, the Holston Army Ammunition Plant nitrates hexamine into RDX in nitric acid and acetic anhydride, and a recycled containerboard mill sits between them. All of it moves acid. Marspec Technical Products fabricates the PTFE-, PVDF- and polypropylene-lined spools and supplies the lined fittings and valves that carry it, with spools shipping from Fairhope, Alabama. Call (251) 625-4949.

If you have a line list, a photo of a leaking spool or a turnaround package, send it over and we will quote it, or contact us online.

What Kingsport actually pumps

Acetyls, cellulose and copolyesters

In 1983 the anchor complex became the first U.S. plant to make acetyl chemicals from coal, and it makes its acetyl chain from gasified coal: synthesis gas to methanol, methanol to methyl acetate, and on to acetic acid and acetic anhydride. The anhydride acetylates wood pulp into cellulose acetate flake, tow and cellulose ester resins, with sulfuric acid as catalyst. Hot glacial acetic acid, acetic anhydride and acid-catalyst mixtures attack carbon steel and corrode 316 stainless at temperature, and the iron they pick up discolors the product. That is the plain case for PTFE-lined pipe and PFA-lined valves: the liner resists the whole acetyl family at process temperature, and the steel housing supplies the pressure rating without touching the fluid. The copolyester units add glycols and terephthalates, and the methanolysis plant was built to take in more than 100,000 metric tons of polyester waste a year in hot methanol.

RDX on the Holston

The ammunition plant has made military explosives for more than 80 years, and its modernization, which the Army values at more than a billion dollars, includes a gas-fired steam plant with 250,000-pound-an-hour boilers and up to one million pounds an hour of output, a nitration facility, a two-train weak acetic acid recovery plant with its own tank farm, and an industrial wastewater plant with its own equalization basins. Nitration means concentrated nitric acid, acetic anhydride, ammonium nitrate and acetic acid in one vessel, followed by spent acid that is recovered and concentrated back to about 55 percent acetic acid. The mixed-acid and recovery lines are where PTFE-lined spools, PFA-lined plug valves and lined sampling valves replace exotic alloys at a fraction of the cost.

Containerboard, water and the rest of the Tri-Cities

The Kingsport paper mill, once a white-paper mill, makes about 600,000 tons a year of recycled linerboard and corrugating medium, one of the largest recycled containerboard mills in North America. A recycled mill still runs caustic and peroxide in pulping and sulfuric acid and alum at the wet end. The city treats about 16 million gallons a day of Holston River water and an average of 9 million gallons a day of wastewater with sodium hypochlorite and coagulants. In Bristol, a welded stainless, duplex and nickel alloy pipe mill pickles every length in nitric and hydrofluoric acid.

Lined pipe for Kingsport service

Custom spools from 1/2" through 12", up to 20 ft, fabricated to your isometric with PTFE, PVDF or polypropylene liners in carbon steel or 304/316 stainless housings. Elbows, tees, reducers, laterals and flanged nipples come from the same shop so liner and flange details match end to end. See our lined pipe and fittings page for liner limits by chemical and temperature.

For acetic anhydride, mixed nitric and acetic acid and hot glacial acetic acid, we point you to PTFE-lined spools and PFA-lined ball or plug valves. PVDF handles dilute acetic acid at moderate temperatures and dilute or on-site hypochlorite at pH 12 or below, and is an option on utility deionized water, though we put high-purity water in PTFE. PTFE covers commercial-strength hypochlorite, dilute caustic, alum and wastewater as well; polypropylene is available for the caustic, alum and wastewater lines where a specification calls for it. Lined diaphragm, butterfly, check and sampling valves are on our lined valves page.

Piping accessories, including lined strainers, expansion joints, PTFE spacers and spectacle blinds, sight glasses and solid PTFE pipe, ship with the spools. Glacial acetic acid freezes at about 62 degrees Fahrenheit and 50 percent caustic at about 54, so for outdoor racks in an East Tennessee winter we supply clamp-on steam heaters, electric tracing and heat-transfer compound from our temperature maintenance line. For jacketed or traced service, we recommend specifying PTFE.

What stands behind the nameplate

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 is spark tested at a minimum of 10,000 volts. Liner temperature limits, liner thicknesses, flange dimensions and torque tables are on our technical details page, backed by more than half a century in plastic-lined piping.

Kingsport, Johnson City and Bristol

We ship custom spools fabricated in our own shop to Kingsport, Johnson City, Bristol, Elizabethton, Greeneville, Rogersville and Morristown from Fairhope, Alabama. Call (251) 625-4949 or contact us online with the line size, the fluid and the temperature.

FAQ: Lined Pipe in Kingsport, TN

Will PTFE-lined pipe handle the nitric acid and acetic anhydride mixture used in RDX nitration?

Yes. PTFE resists nitric acid, acetic acid and acetic anhydride across the concentrations used in nitration and acid recovery, which is why lined pipe is the usual answer where mixed acids would otherwise call for tantalum or high-silicon alloys. We supply the spools, lined plug valves and sampling valves as a matched package.

What liner do you recommend for acetic acid recovery lines at a Kingsport cellulose ester unit?

PTFE for hot glacial acetic acid and anhydride. PVDF is acceptable for dilute acetic acid at moderate temperature. Both keep iron out of the acid, which matters when the recovered acid goes back into cellulose acetylation.

Can you match the flanged lined pipe already installed at a Tri-Cities plant?

Yes. Our fittings conform dimensionally to ANSI B16.5 and we fabricate spools to your face-to-face dimensions, so a replacement bolts into the existing run. Send the isometric or a photo of the tag and flange.

Do you supply lined valves for sodium hypochlorite at the Kingsport water and wastewater plants?

We do. Lined diaphragm valves, with a PFA-lined body and a PTFE-faced diaphragm, or PFA-lined ball valves with a vented ball (vent facing upstream) suit hypochlorite: the lining keeps out the metal ions that speed its decomposition, and the vented ball keeps the gas it gives off from building pressure in a closed ball cavity. We supply PTFE-lined spools for the feed and dosing lines to go with them, with PVDF an option for dilute or on-site hypochlorite at pH 12 or below.