Plastic Lined Pipe Fittings in Louisiana

Louisiana's river and ship-channel plants run on turnaround schedules, and an outage is when worn lined fittings come out. Marspec Technical Products supplies PTFE-, PVDF- and polypropylene-lined fittings for that work and fabricates custom spools in Fairhope, Alabama, a Gulf Coast neighbor. PTFE lined fittings in carbon and stainless steel are stocked; PVDF and polypropylene lined to order. Call (251) 625-4949 with the tag list for your next outage.

Our Louisiana page has the statewide overview, and the Baton Rouge, New Orleans and Lake Charles pages cover each corridor in depth. Here we stick to fittings. Contact us online with a tag list or a marked-up isometric.

What Louisiana service asks of a fitting

Chlor-alkali on the river

At Plaquemine, a vinyl complex makes its own chlorine and caustic soda for VCM and PVC. At Taft, where chlor-alkali production started in 1966, a membrane cell plant was converted to make potassium hydroxide. Wet chlorine, brine, hypochlorite and HCl take PTFE-lined fittings with vented housings, because chlorine and HCl permeate the liner. Caustic soda and caustic potash take PTFE as well; PVDF is not used above about pH 12.

Hot caustic

Caustic concentrated to 73 percent turns solid at roughly 145 °F, so it has to travel hot from evaporator to loading rack. Fully jacketed fittings, built to match jacketed spools, keep it liquid through every elbow and tee, not only along the straight runs. At the chlor-alkali units of Lake Charles and the river parishes, even 50 percent caustic crystallizes on a cold night. Clamp-on steam heaters or electric tracing cover lines that only need freeze protection.

Nitrogen and refining

Downriver at Donaldsonville, a 1,400-acre complex has about 4.3 million tons a year of ammonia capacity, much of it upgraded to granular urea and UAN. Where nitric acid and ammonium nitrate solution need lined fittings, PTFE is the liner. Polypropylene is not an option for nitric acid, and we prefer PTFE for ammonia. Refineries from Lake Charles to Garyville add alkylation sulfuric acid, spent caustic and sour water, all PTFE service within the liner's 450 °F limit.

Fittings that solve rack problems

• Reducing run tees change size at the branch and can eliminate a concentric reducer or reducing flange in a crowded river rack.
• Standard and lug-body instrument tees give a lined outlet, with a rotating flange, for a gauge, transmitter or sample point.
• Laterals bring a drain or cleanout in at 45°, an easier path for solids than a square tee.
• Spacers, 1/2" thick, fill the step where a lined valve's raised face differs from the fitting beside it. Solid spacers with tapped side holes are available for flow orifice use.
• Blind flanges in Class 150 or 300 close off future tie-ins and isolate a header during an outage.
• Class 300 lines are covered by true 300 lb elbows, 300 lb tees and reducing tees, and Class 300 instrument tees.

The rest of the range covers 90° and 45° elbows, 90° reducing elbows, equal and reducing tees, short-stack tees and crosses, and standard crosses. It also includes concentric and eccentric reducers, reducing flanges, scalloped and straight-bore reducing flanges, and custom spools up to 20 ft. Housings come in carbon steel or 304/316 stainless, with sizes from 1/2" through 12". Dimensions are tabled on our lined pipe and fittings page; liner thickness, flange and torque data are on Technical Details.

A turnaround fitting list that matches the first time

1. Tag or line number, size, flange class, and whether the flanges rotate or are fixed.
2. The existing liner, plus fluid, concentration and temperature if the service has changed since the line was built.
3. Housing material: carbon steel, 304 or 316 stainless.
4. The center-to-face or face-to-face dimension, measured on the fitting coming out.
5. Your required date, so we can quote a fabrication time against it.

Our fittings conform dimensionally to ANSI B16.5, so a measured dimension and a flange class usually settle the match. Lined valves for the same lines are on our lined valves page and our Louisiana valve page. Our Louisiana accessories page covers the strainers, expansion joints and blinds.

Testing and standards

Every lined spool and fitting is spark tested at a minimum of 10,000 volts, and any audible or visible spark rejects the liner. The lined fittings we supply are welded to ASME B31.3 by welders certified to ASME Section IX and, like our lined pipe, comply with ASTM F1545. Lined fittings carry identifying markings on their flanges in accordance with ASTM F1545, and carbon steel housings are primed for field top-coating. We have been in lined pipe for more than half a century.

Serving Louisiana from Lake Charles to the River Parishes

We supply plants in Lake Charles, Westlake, Sulphur, Baton Rouge, Geismar, Plaquemine, Donaldsonville, Taft, Norco, Garyville, Convent, New Orleans, Monroe and Shreveport. Call (251) 625-4949 or contact us online, and send the fitting list as soon as the outage scope is known.

FAQ: Plastic Lined Pipe Fittings in Louisiana

Can PTFE-lined fittings for a Geismar or Plaquemine turnaround come from stock?

Standard PTFE-lined shapes in carbon steel and stainless are stock items, while PVDF and polypropylene fittings are lined to order. Send the list with your required date, and we will quote what is on hand and a fabrication time for the rest.

What fittings suit 73 percent caustic at a Lake Charles chlor-alkali plant?

Fully jacketed PTFE-lined fittings matched to jacketed PTFE-lined spools, so the caustic stays above its solidification point at every turn. PVDF is not used for caustic above about pH 12.

Do you supply Class 300 lined fittings for Baton Rouge refinery service?

Yes. True 300 lb elbows, 300 lb tees and reducing tees, Class 300 instrument tees and Class 300 blind flanges are available. Put the flange class on the line list so the drilling matches the rack.

Which liner do you recommend for nitric acid and UAN fittings at Donaldsonville?

PTFE, which handles nitric acid and hot ammonium nitrate solution. Polypropylene is never used for nitric acid, and jacketed fittings help where UAN or ammonium nitrate would crystallize in a cold snap.