Lined Pipe in Arizona

Arizona mines about seven of every ten pounds of copper produced in the United States, and much of it is recovered by leaching ore with sulfuric acid and plating it out in electrowinning tankhouses. Add the wafer fabs in north Phoenix and Chandler and you have a state whose core industries live on acid, caustic and ultrapure water. Marspec Technical Products fabricates PTFE-, PVDF- or polypropylene-lined pipe spools and supplies the lined fittings and valves those fluids require, with spools shipping to Arizona from Fairhope, Alabama.

Call (251) 625-4949 or contact us online with a drawing or a line list. After more than fifty years in plastic-lined piping we can usually quote from a sketch and a description of the service.

Where Arizona uses lined pipe

Copper leaching, solvent extraction and electrowinning

The porphyry copper operations at Morenci, Safford, Bagdad, Miami, Ray and Sierrita, together with the Miami smelter, make up the largest concentration of copper plants in the country. Heap and stockpile leaching drips dilute sulfuric acid over crushed ore. Pregnant leach solution flows to solvent extraction, where an organic extractant in kerosene diluent picks up the copper, and stripping with strong acid electrolyte sends it on to the electrowinning cells. The acid comes from the Miami smelter's acid plant and from sulfur burners at the mines. Raffinate, electrolyte and acid headers in these circuits are a natural fit for lined pipe. PTFE liners are unaffected by sulfuric acid across the whole concentration range used in SX/EW, and they tolerate the organic phase that swells many elastomers. Lined plug and ball valves handle the isolation, and lined strainers protect the electrolyte pumps from crud.

Semiconductors and the chemical supply chain

Arizona is a major semiconductor state. The fab complex in north Phoenix, the fabs in Chandler and the chemical suppliers around Casa Grande and the West Valley all depend on fluids that cannot touch bare steel. A large fab draws several million gallons of water a day, polishes it with reverse osmosis, ion exchange and electrodeionization, and reclaims most of it on site. Inside the fab, ultrapure water and electronic-grade chemicals run in solid natural PVDF or PFA. Lined pipe and lined valves are for the bulk chemical supply, acid waste and neutralization systems that handle hydrofluoric, sulfuric, nitric and phosphoric acids, ammonium hydroxide, peroxide and solvent waste, and PTFE-lined spools carry mixed acid waste to the neutralization plant.

Water, food and metal finishing

Phoenix, Tucson and the Pinal County towns treat enormous volumes of water: Colorado River water from the Central Arizona Project, salty groundwater and reclaimed effluent. Their plants dose sodium hypochlorite, ferric chloride and sulfuric acid, and the hypochlorite and ferric chloride pit stainless and chew through carbon steel. Dairy and produce processors in Maricopa, Pinal and Yuma counties cycle caustic and nitric acid through their CIP systems, and aerospace and defense plants in Tucson and Mesa run anodizing, chromate and pickling lines.

What we build for Arizona plants

• Custom lined spools to 20 ft, sizes 1/2" through 12", lined with PTFE, PVDF or polypropylene in carbon steel or 304/316 stainless
• Lined elbows, tees, crosses, laterals, reducers, flanged spacers and instrument tees
• Lined valves: ball, plug, butterfly, diaphragm, check and sampling, with PTFE or PFA liners
• Piping accessories: lined strainers, expansion joints, spectacle blinds, sight glasses and solid PTFE pipe
• Temperature maintenance: clamp-on steam heaters, electric heat tracing and heat-transfer compound

Two Arizona conditions deserve a word. First, summer sun on an outdoor rack can push a line well above ambient, and polypropylene's chemical resistance and vacuum rating fall as it warms toward its 225 °F (107 °C) limit, so for hot outdoor acid or electrolyte lines we recommend PTFE. Second, the mining districts sit at elevation and see hard winter nights, and a 50 percent caustic line or a stagnant electrolyte line will crystallize or freeze there. Electric tracing or a clamp-on steam heater under insulation keeps it flowing without exceeding the liner's temperature limit. For jacketed or traced service, we recommend specifying PTFE.

Standards behind every spool

Our lined pipe and fittings comply with ASTM F1545, and every fitting conforms dimensionally to ANSI B16.5. The lined fittings we supply are welded to ASME B31.3 by welders certified to ASME Section IX. Before any lined spool or fitting leaves the shop it passes a minimum 10,000-volt spark test of the liner, so a pinhole is caught before it reaches your leach pad or your fab. Liner temperature limits, liner thicknesses, flange dimensions and torque tables are listed on our technical details page.

Serving Phoenix, Tucson and the copper districts

We ship spools nationwide from Fairhope, Alabama, and Arizona orders travel the same route whether they are headed to Phoenix, Chandler, Tempe, Mesa, Casa Grande, Tucson, Sahuarita, Yuma, Morenci, Safford, Globe-Miami, Hayden, Bagdad or Kearny. Custom spools built to field dimensions are most of what we do, and a leaking acid header is the kind of job we quote from a sketch. Call (251) 625-4949 or contact us online and tell us the line size, the medium and the temperature.

FAQ: Lined Pipe in Arizona

Which liner works best for sulfuric acid in an Arizona SX/EW circuit?

PTFE handles the dilute raffinate and the strong electrolyte used in solvent extraction and electrowinning, and it is what we recommend and quote: it is the safer choice where the organic extractant and diluent are present or where temperatures climb. The kerosene diluent in loaded organic can build a static charge that pinholes a plain lining or ignites vapor, so bond and ground the spools and use anti-static PFA-AS valves; tell us if your specification calls for an anti-static liner. PVDF, within velocity limits, suits lines with entrained solids that abrade softer liners, and polypropylene is available for the dilute, cooler lines where a specification calls for it.

Can your pipe serve bulk chemical and acid waste lines in a Phoenix or Chandler fab?

Yes, for bulk chemical supply, acid waste and neutralization. PTFE-lined pipe and PFA-lined valves handle hydrofluoric and mixed acid service, because the liners add no metal ions and the steel housing carries the pressure. Ultrapure water and electronic-grade chemicals run in solid natural PVDF or PFA rather than lined pipe.

Do you supply lined pipe for sodium hypochlorite and ferric chloride at Arizona water plants?

We do. Both chemicals attack stainless steel, and PTFE-lined pipe with lined diaphragm valves, or ball valves with a vented ball (vent facing upstream) on the hypochlorite, is a common specification for chemical feed lines at water and wastewater plants in Phoenix, Tucson and the Central Arizona Project service area.

How do we keep a caustic or electrolyte line from freezing at a high-desert mine?

Our temperature maintenance products include electric heat tracing, clamp-on steam heaters and heat-transfer compound that keep the line warm under insulation while staying within the liner's rating. For jacketed or traced service, we recommend specifying PTFE. Tell us the medium and the lowest ambient temperature and we will size it.