Lined Pipe in Minnesota

Minnesota mines most of the iron ore in the United States, refines more crude oil than any other state without an oil well, grows more sugar beets than anyone, and ranks near the top in ethanol. Those are four very different industries with one thing in common: acids, caustics, brines and chloride-laden process water that shorten the life of steel and stainless pipe. Plastic-lined pipe and valves solve that problem without exotic alloys, and we have been fabricating them for more than half a century.

Marspec Technical Products fabricates PTFE-, PVDF- and polypropylene-lined steel pipe spools and fittings from 1/2" through 12" in Fairhope, Alabama, supplies lined valves and piping accessories, and ships nationwide. For a Minnesota project, call (251) 625-4949 or contact us online with your line list.

Where lined pipe goes to work in Minnesota

Taconite on the Mesabi Range

The Iron Range produces the large majority of the nation's iron ore, shipping on the order of 30 to 35 million tons of taconite pellets in a typical year from plants at Mountain Iron, Keewatin, Hibbing, Virginia, Eveleth and Forbes, and Babbitt and Silver Bay. Taconite processing crushes and grinds the ore, separates magnetite with magnetic drums and flotation, and rolls the concentrate into pellets with bentonite before firing. The chemistry around that process is harder on piping than people expect: flotation reagents and pH modifiers, sulfuric and hydrochloric acid for descaling and water treatment, hypochlorite and biocides in recirculated process water, and high-chloride water that pits stainless. Lined pipe and lined plug and ball valves on reagent and acid systems outlast the alternatives.

Two refineries on the Mississippi

The Pine Bend refinery at Rosemount is the largest refinery in any state without oil production and runs well over 300,000 barrels a day, about four-fifths of it heavy Canadian crude. A few miles upstream, the St. Paul Park refinery processes roughly 106,000 barrels a day on the east bank of the river below St. Paul. Together they supply most of the gasoline sold in Minnesota. Heavy, sour crude means large sulfur recovery, amine and sour water systems, spent caustic, sulfuric acid alkylation and acid regeneration, and demineralizer trains regenerated with hydrochloric acid and caustic. PTFE-lined spools, lined fittings and lined valves are the standard answer for those lines, with vented housings on the hydrochloric acid because HCl permeates the liner.

Sugar beets, ethanol and the food industry

Minnesota is the leading sugar beet state. Factories at Moorhead, Crookston and East Grand Forks in the Red River Valley, and at Renville in the Minnesota River valley, run lime and carbonation, sulfur dioxide, ion-exchange regeneration with hydrochloric acid and caustic, and hot caustic and acid cleaning cycles through the campaign. The state is also among the top five ethanol producers, with eighteen plants and roughly 1.4 billion gallons of annual capacity, and plants at Janesville, Heron Lake and elsewhere move sulfuric acid, caustic, ammonia and CIP chemicals every day. Flour milling, dairy and meat processing and soybean crushing across the southern half of the state add steady demand for lined pipe on CIP chemical distribution and brine service.

Pulp, medical devices and water

A large kraft pulp mill at Cloquet on the St. Louis River and the paper mill at International Falls on the Canadian border run chlorine dioxide, hypochlorite, peroxide, caustic and sulfuric acid through their bleaching and chemical systems. The Twin Cities medical device industry passivates, electropolishes and plates in nitric, citric and chromic acid baths, and semiconductor fabrication in the south metro needs high-purity acid and solvent distribution with no metal ion pickup. Municipal water and wastewater plants from the Twin Cities to Duluth and Rochester feed ferric chloride, alum, sodium hypochlorite and fluorosilicic acid year-round.

The Marspec line for Minnesota

Our custom lined pipe spools run up to 20 ft in PTFE, PVDF or polypropylene, in carbon steel or 304/316 stainless housings, and we supply lined elbows, tees, reducers, laterals and instrument tees to the same dimensional standards. We supply lined ball, plug, butterfly, diaphragm, check and sampling valves, plus lined strainers, expansion joints, spacers, spectacle blinds, sight glasses and solid PTFE pipe. The rest of the catalog is on our Other Products page.

Winter is a design condition

On the Iron Range and in the Red River Valley, outdoor chemical lines see weeks below zero. Fifty percent caustic crystallizes near 54 degrees F, hypochlorite freezes and loses chlorine, and ferric chloride and sulfuric acid at common strengths will solidify. Our clamp-on steam heaters, electric heat tracing and heat-transfer compound mount on the outside of the lined spool, so the liner is never exposed to jacket temperatures and the line stays fluid through the coldest week of January.

Specifications we build to

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 receives a minimum 10,000-volt spark test. Liner ratings for pressure, temperature and full vacuum are on our Technical Details page.

Serving the Twin Cities, Duluth, the Iron Range and the Red River Valley

We ship to Minneapolis, St. Paul, Rosemount and St. Paul Park, Duluth and Cloquet, Hibbing, Virginia, Mountain Iron, Keewatin, Silver Bay and the rest of the Range, International Falls, Moorhead, Crookston, East Grand Forks, Rochester, Mankato, Marshall, Willmar and St. Cloud. Call (251) 625-4949 or contact us online, and send isometrics to info@linedpipe.com for a quick quote.

FAQ: Lined Pipe in Minnesota

What lined piping do you supply for taconite plants on the Iron Range?

Lined spools, fittings and valves for acid, flotation reagent, hypochlorite and chemical feed systems, typically PTFE or PVDF for acids and PTFE for caustic and brine, with polypropylene available for the caustic and brine where a specification calls for it. Lined plug and ball valves hold up in slurry-adjacent chemical service where stainless pits.

Can your lined pipe handle sulfuric acid and spent caustic at the Pine Bend and St. Paul Park refineries?

Yes. PTFE-lined carbon steel pipe is rated for concentrated sulfuric acid and spent caustic across the operating temperatures of alkylation and treating units, and our fittings mate directly to ANSI B16.5 flanges in existing racks.

Which liner is right for a Red River Valley sugar beet factory?

PTFE for caustic, lime-side cleaning chemicals, hydrochloric acid regeneration and the widest temperature range, PVDF for sulfur dioxide water and hot acid, and polypropylene for the caustic lines if the specification names it. We can mix liners across one order to match each service.

How do you handle a lined pipe order for a Minnesota plant?

We fabricate custom spools to order in our own shop, shipping nationwide from Fairhope, Alabama. Send us the line list and we will give you a firm fabrication time with the quote.