Pigging ends freezeups in caustic piping system

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Chem. Process. (Chicago); (United States)

OSTI ID:5675944

Gros, R; Gaines, A

Convent Chemical Corporation in Convent, LA produces and ships bulk quantities of chlorine and caustic soda (NaOH). The caustic soda is available in various grades, including a 50% aqueous solution that freezes at 56/sup 0/F. An extensive network of chemical-resistant polypropylene-lined steel pipe (without heat tracing) is used to transfer the caustic soda from the production area to storage tanks and to the loading facilities for tank trucks, rail tank cars and barges. A sudden drop in ambient temperature can cause freezeup of the caustic transfer pipes which may result in downtime of as much as a week. Convent plant engineers designed a pigging system for the outdoor caustic transfer lines in the tank farm and to the loading stations. The patented design pig, (internal pipeline cleaner) consists of a flexible, bullet-shaped cylinder of chemical-resistant polyurethane foam with strips of urethane rubber on the surface, or with a solid coating of the tough material. Fluid or gas pressure on the sealed concave base propels the flexible pig through the pipe, valves, elbows, and other fittings, and material ahead of the pig is discharged into an appropriate receiver. The pigging system has eliminated the caustic freezing and plugging problems since it was installed in the summer of 1981. The flexible pig, propelled by 80 psi air, is used to clear the pipelines whenever caustic is transferred during the winter months. The air-propelled pig is designed and sized to easily pass through restrictions in the piping system, such as reduced port plug valves, but was once stuck when it reached a section of pipe that had collapsed. A pig containing the Cobalt 60 nuclear element was inserted into the line to quickly locate the stuck pig with the Geiger counter. The faulty section of pipe was replaced with a new polypropylene lined spool piece.

• Research Organization: Convent Chemical Corp., LA
• OSTI ID: 5675944
• Journal Information: Chem. Process. (Chicago); (United States), Journal Name: Chem. Process. (Chicago); (United States); ISSN CHPCA
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320205* -- Energy Conservation
Consumption
& Utilization-- Transportation-- Pipeline
ALKALI METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL PLANTS
CHLORINE
CLEANING
COBALT 60
COBALT ISOTOPES
DETECTION
ELEMENTS
FREEZE PROTECTION
FREEZING
GAMMA DETECTION
HALOGENS
HYDROGEN COMPOUNDS
HYDROXIDES
INDUSTRIAL PLANTS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MINUTES LIVING RADIOISOTOPES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
PIPES
RADIATION DETECTION
RADIOISOTOPES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
YEARS LIVING RADIOISOTOPES