High-Performance Plastic Components Stand Up to Hostile Conditions
Engineering Challenge
Few industries are as demanding on their equipment as oil and gas exploration and production. Extreme temperatures, harsh environmental conditions, corrosive seawater, chemical exposure, and extraordinary friction and wear demands all add up to make uninterrupted operation one of engineering’s greatest challenges.
High-performance polymers offer many advantages over metal when used appropriately for machined components in oil and gas applications. With their light weight, cost-efficiency, durability, and resistance to heat, steam, chemicals, and corrosion, they improve performance and add exceptional value wherever they are applied: underground or in subsea systems, downhole or in rigging operations, and in exploration, oil refining, or hydraulic fracturing (fracking) operations.
Here are some of the most common plastic materials used in oil and gas exploration, extraction, and refining.
PEEK
PEEK plastic is widely specified in the oil and gas industry due to its exceptional performance characteristics.
Some key characteristics of PEEK:
- Resistance to harsh chemical and corrosive environments, including hydrogen sulfide at elevated temperatures
- Superb hydrolysis resistance with high retention levels of mechanical properties after prolonged exposure to steam or sea water at elevated temperatures
- Broad operational temperature range
- Low levels of creep and excellent mechanical properties, which can be further enhanced by the addition of fillers such as glass and carbon fibers
- Abrasion and wear resistance under high loads (bearing grades)
Common oil and gas applications for PEEK include:
- Seal and packing components, such as backup rings, piston seals, and labyrinth seals
- Subsea connectors
- Poppets
- Valve seats
- Compressor valve plates
PTFE
Whereas PEEK is often used as an anti-extrusion backup due to its high strength characteristics, PTFE is softer and more ductile, which causes it to expand under compressive load and create an effective seal. PTFE is often specified where other common sealing materials, like elastomers, cannot meet the thermal, chemical, or tribological (friction, lubrication, and wear) demands of the application.
Some key characteristics of PTFE:
- Exhibits the broadest chemical resistance of any commercially available polymer, due to its simple, fully fluorinated structure
- Maintains ductility in cryogenic environments
- Static and dynamic coefficients of friction are functionally equivalent, resulting in virtually no observable stick-slip phenomenon
- Absorbs only a negligible amount of moisture
Common oil and gas applications of PTFE include:
- Seal and packing components, such as O-rings, backup rings, spring-energized seals, slipper seals, and piston rings
- Sealing liquid natural gas or other cold media
- Bearing and wear components (filled grades)
Other Proven High-Performance Materials for Oil and Gas Applications
DuPont™ Vespel® Polyimide SP and SCP Materials
- Ball valves and backup rings, especially Vespel® SP-21
PPS (often filled grades)
- Lantern rings
- Downhole insulators
- Sheaves
- Poppets
- Wear pads
- Various bearing components
Source: https://www.curbellplastics.com