Unravelling Polymers

The Definitive Blog on Polymers by Poly Fluoro Ltd.

High-Performance Polymers in Oil & Gas Applications

The growth of the oil & gas industry has been one of the cornerstones of the industrial boom over the past century. While the processes of extraction, storage, refining, and distribution have all been in place for a while, the technologies in the background have continued to evolve. Further, as new and improved methods were developed, they have required the use of special materials to be incorporated.

The polymer industry has always been closely connected to oil & gas by virtue of the fact that many polymers are derived as by-products of the oil refining process. The supply and pricing of polymers such and polyethylene and polypropylene move almost in tandem with oil prices as a result. However, these base polymers are rarely the ones used in oil & gas equipment. The presence of corrosive chemicals, high-temperatures, and rough handling necessitates the use of high-performance plastics.

Polymers such as PTFE, PEEK, and PPS are especially useful because they are able to withstand multiple forces and require minimal maintenance. This means that they can be installed in equipment deep within a system and it is assured that they would not need to be constantly checked on.

Considering PTFE, PEEK, and PPS are all stable up to temperatures of 260°C, they are invaluable in oil & gas applications.

PTFE and PEEK Packing Rings

Packing rings, V-rings, V-packings or Chevron Packings are commonly used in oil extraction equipment. These components are usually made with PTFE, PEEK, or PPS and incorporate a carbon filling for added wear properties. Chevron rings are usually made to be stacked one above the other and then fitted as a single element around a metal shaft. The rings protect the shaft from wear and are themselves resistant to the gases and heat that the shaft will also experience.

Given that the rings are machined with v-grooves and that they need to fit into one another perfectly, not all manufacturers are able to make such components. Care needs to be given to tolerances, which can be as low as 2 microns, to ensure a fit. Further, special attention needs to be given on the blending of carbon, as this needs to be uniform if the part is to have a life of 10-15 years, as required.

Sealing Rings and Gaskets

Sealing rings and gaskets are especially useful in high-pressure environments. Not only does the oil & gas process involve corrosive chemicals at high temperatures, but the pressures at which these push their way through the system can be highly erratic.

Sealing rings and gaskets – usually made with PTFE or a PTFE+PPS blend – need to be soft enough to create an adequate seal, but hardy enough to take high pressures without deforming.

Sealing rings are normally used in metal-to-metal joints and should be able to take pressures in excess of 100 Bar. They are integral in ensuring that the system does not leak and/or lose pressure – both of which can have highly adverse effects.

Valves, seats, and conduits

Polymer valves – such as butterfly valves, ball-valves, or even specialized valves and conduits – are vital to managing flow within a system. The liquids or gases within these systems can corrode even robust materials like stainless steel. PTFE and PEEK are often used as ball-valve-seats, while PTFE and PPS can also be machined to make special valves and t-joints to ensure that the system is not eaten away over time by the chemicals present.

PTFE Pipe Lining

PTFE pipe lining is a common process to ensure that large pipes – usually made using mild steel – are kept protected from corrosion. The PTFE is first extruded as a pipe with a wall thickness of 2.5-4mm and this is then drawn into the mild-steel pipe using a hydraulic press to create a uniform layer inside the steel pipe. The layer of PTFE within the mild steel ensures that the metal is totally protected. Such lined pipes are essential to create a piping system that can survive years, or even decades without getting corroded or developing leaks.

PTFE Sliding bearings

While the primary purpose of polymers is to protect and create efficiencies within fluid systems, PTFE also finds application in the bearings that allow oil & gas pipelines to stretch across vast distances. The sliding bearing is made using a layer of PTFE and sits under the pipe support. The purpose of the bearing is two-fold. First, it allows for compressive loads to act upon it. The high compressive strength of the PTFE is needed for this. More importantly, PTFE’s low coefficient of friction allows for a sliding movement. This movement is crucial since a metal pipeline will experience tremendous thermal expansion and contraction during the course of a single day. The sliding movement of the bearing allows for this and ensures that no stress develops under the pipe supports that may lead to pipes being damaged or the supports collapsing.

PTFE Tubes

No fluid system is complete without the incorporation of PTFE tubes. Like lined pipes, the tubes allow for the passage of fluids without succumbing to corrosion or fracturing under high pressure. PTFE tube is expensive, so its use is mainly restricted to areas where it is absolutely necessary.

Certain applications – such a labs and research set ups – will use PTFE umbilical cords to transport gases from the refining process and to the labs for testing. The composition of these gases tells us whether the refining process is producing the right results. Since the gases cannot react with anything else before they reach the lab, PTFE is used. Typically, there will be 12-15 different separate gases to collect, so the cord is composed of a bundle of tubes, each at least 200-500 meters long.

Sealing materials

Beyond sealing rings, various polymer sealing materials are also incorporated into oil & gas systems. A key product is ePTFE (expanded PTFE) gasket tape. This is a soft, highly compressible tape made using pure PTFE. As such, it has all of PTFE’s properties, with the added benefit of being up to 65% compressible.

ePTFE tape can be made from anywhere as low as 0.2mm to as high as 15mm thick. In effect, the tape can be laid between two metal components and the system tightened to ensure that the gap between the two metals is completely sealed. A typical flange-to-flange connection can be installed using expanded PTFE and will stay perfectly sealed for years on end.

Again, like PTFE, the tape can withstand high temperatures and pressures of up to 100 Bar, making it a vital product in any fluid system.

Specialized components

Over the years, Poly Fluoro has had the opportunity to develop multiple specialized systems and components for the oil and gas industry. From special molding frames using PTFE+Glass, measuring and analysis chambers using a combination of PTFE, PVC, and acrylic, and even heat exchanger assemblies for chemical baths. Our expertise in machining, forming, extruding, and molding high-performance polymers allows us to understand the problems from first principles and identify the right polymer needed for the application.

Read More


1. High Performance Polymers in Railway Applications

2. Polymer Sealing Solutions – High Performance Seals, Valves, and Seats

3. Polymer Wear Plates - Grade Selection and Key Advantages

PTFE Pricing Update – The Post-COVID Scenario

Over these past two years, virtually no supply chain in the world has been immune to the vagaries of price fluctuations. The initial onset of the pandemic did not immediately result in inflationary pressures. This was possibly a combination of caution on the side of the suppliers of raw materials combined with the uncertainty that demand would persist across industries. However, once the dust somewhat settled, it became obvious that demand was still robust. Not only that, the general climate since 2021 has been one of exuberance, with the result that prices of PTFE have experienced a steady uptick month-on-month.

It should be noted that while PTFE prices have seen an upswing of anywhere between 25-40%, price escalations for other polymers have been even more pronounced. For POM (Polyacetal), for example, the price moved from a low of ~US$1.75 in 2019 to ~US$4.35 today – as staggering 2.5X increase. Other plastics such as ABS, Polypropylene, and PVC have seen similar jumps, if not as pronounced.

PTFE prices

 
  Virgin PTFE+15% Glass

PTFE+40% Bronze

Apr-10 360 510 750
May-10 360 575 750
Jun-10 360 575 750
Jul-10 375 575 750
Aug-10 390 575 750
Sep-10 475 575 750
Oct-10 500 575 750
Nov-10 525 600 825
Dec-10 525 675 825
Jan-11 650 700 950
Feb-11 725 775 1000
Mar-11 750 850 1050
Apr-11 900 900 1100
May-11 925 900 1100
Jun-11 925 950 1100
Jul-11 1200 1250 1350
Aug-11 1200 1250 1400
 

PTFE prices-21-22

Today, while price revisions continue to be sprung at the beginning of each month, it is probably wise to take stock of the pricing pressures presently at play and understand how the next 12 months might look. Broadly, there are four levers impacting the climate of PTFE pricing.

1. The war in Ukraine

Perhaps the most significant event over the last six months, the war has had multiple ripple effects across various economies and industries. If we look at the impact on PTFE, the effects are threefold:

  1. PTFE resins from Russia are well accepted and widely regarded as being of good quality. However, the war has forced many European nations from cutting ties with Russia and the subsequent shortage of Russian resins has put pricing pressures on PTFE raw materials.

  2. The resulting hike in oil prices pushed up the costs of shipping, forcing many processors to buy locally. This has put tremendous pressure on resin manufacturers. In India, Gujarat Fluorochemicals – who have monopoly on indigenous manufacture – have been operating at capacity. Orders that would otherwise have been available ex-stock now take 3-4 weeks to be dispatched. At the same time, MOQs have increased, as the focus shifts to pushing out as much of a given grade as possible before moving to another grade.
    (It should be noted that PTFE does not directly get impacted by oil prices. Many clients assume that as it is a polymer, its fate is somehow linked to oil. However, PTFE is made via an entirely different process and as such does not get impacted when oil prices fluctuate).

  3. The energy crisis created by the war in Ukraine – both for oil and natural gas – has caused steep escalations to the cost of production in Europe. This has, in-turn, made the manufacture of PTFE resins very costly and even with the higher shipping costs, it has made sense for them to import materials from India and China. This added displacement in demand has put the bulk of the pressure for supply on Indian and Chinese manufacturers, pushing prices up as a result.

2. Capacity expansion

COVID ensured that any major additions of capacity would need to be put on hold. However, the subsequent spurt in demand found many raw material suppliers struggling to meet their target timelines. Since 2021, the addition of capacity within China has seen many resin manufacturers step out and start re-building their dealer bases in India.

In India, the entry of SRF into the PTFE resin space remains a very significant event. While initial reports suggested they would be production ready Q3 2022, the present status seems to indicate that they may hit the market only by Q1 2023. Either way, the resulting jump in capacity will bring some much-needed competition into the local market and ease off some of the pricing pressures currently being seen.

3. China lockdown

As China pursues an aggressive lockdown policy, the supplies to other countries have been sporadic. Since China remains the largest manufacturer of PTFE resins, this supply inconsistency has caused supply-side ripples across the market. Further, with Russia out of the picture, it has become even more imperative for China to maintain a steady supply into Europe. As COVID pressures ease, we should see some improvement in the flow of materials out of China, which should subsequently relax pricing.

4. The end of anti-dumping duties

Over the past decade, the Indian market has been protected by the prevalence of anti-dumping duties on Russian and Chinese resins. This duty – a fixed amount per Kg that typically implied a price increase in the range of 18-25% - has forced most processors in India to buy only from Gujarat Fluorochemicals. As the present scenario unfolds and demand from Europe spikes, GFL’s grip on the Indian market has become even more pronounced.

However, a July 2022 ruling by the DGFT has abolished anti-dumping duties, leaving the Indian markets open to resin from both China and Russia (India continues to buy from Russia). This move is likely to see a much-needed easing of PTFE prices in months to come.

In conclusion, while PTFE supply-side pressures remain strained in the short-term, the medium to long term effects point to a general easing of pricing. Whether prices will return to their pre-COVD levels seems unlikely. However, the added capacities and competition from China and Russia will certainly keep price escalations in check, even as energy prices remain uncertain.


Read More

1. An overview of key high performance plastics

2. Polymer Sealing Solutions – High Performance Seals, Valves, and Seats 

3. High Performance Polymers in Railway Applications

An overview of key high performance plastics

The polymer landscape is constantly evolving. Even as new methods of production and processing are developed around existing polymers, there exists and ever-expanding field of new-age polymers, many of which will be mainstays of the industry in the years to come. Some of the key niche polymers are listed below. While a few – such as PTFE, PVDF, and even PEEK – are relatively well know, many are yet obscure, with their properties not fully explored or understood. It is imperative that engineers understand these properties and find ways to incorporate these polymers into their future designs.

 

Full Form

Appearance

Key properties

Applications

Brand Names

Specific Gravity

Tensile Strength (Mpa)

Max. Service Temperature (°C)

Young's Modulus (Mpa)

Dielectric Constant

Reinforcements

PEI

Polyetherimid

Amber

Strength, insulation, resistance to hydrolysis (suitable for repetitive steam sterilisation) and radiation. Stiff even at high temperatures

Electronic industries: coils and fuses
Aerospace industries: components for antenna constructions and components for interior equipment

Ultem

1.27

110

170

3100

3.2

Glass

PAI

Polyamide-imide

Dark Brown

Strength, outstanding tribological and wear performance, thermal stability

Semiconductor industry: test sockets, electrical connectors and insulators
Aerospace: fasteners, insulators and other components
Oil and Gas: natural gas compressor components, pump components and labyrinth seals
General industrial: bearing and wear components and components that require high strength and stiffness

Torlon

1.42

152

275

4500

4.2

Carbon

PPS

Polyphenylensulfide

Light Brown

Strength, resistance to high energy radiation, chemical resistance

Electronic industry: Connectors, contact rails, heat shields, contact pressure discs and special types for semi-conductor production
Automotive industry: "under the hood", fuel and brake systems
Medical industry: Parts for surgical instruments
Mechanical engineering: Compressor and pump-parts, gears, valves, slide bearings, chain guides and base plates
Chemical industry: Valves, taps, bushings, pumps, nozzles, tubes and rollers

Tecatron, Ryton

1.35

85

200

15000

3.2

Glass, PTFE

PPSU

Polyphenylsulfone

Clear - made in different colours

Resistance against high energy radiation (gamma and X-rays),  resistance to hydrolysis (suitable for repetitive steam sterilisation)

Medical industry: Test implants/adjustment bodies for hip, knee and shoulder and handles of medical devices

Radel

1.3

77

180

2500

3.4

NA

PES

Polyethersulfone

Dark Brown - translucent

Strength, insulation, microwavable, resistance against high energy radiation, weldable, machinable, thermoforming

Electrical insulation parts such as connectors
Control panel for dialysis system
Valve piston
Pump housing
Membrane for water filtration
Safety face shields

Tecason

1.37

90

180

2700

3.9

Glass

PVDF

Polyvinylidene fluoride

Waxy white

Dimensional stability, resistance to chemicals, hydrolysis, UV, and radiation. Good electrical resistance. High abrasion resistance. Low wated absorption

Chemical plant engineering with higher mechanical stress
Food and pharmaceutical industries with higher temperatures and mechanical loadings
Valves
Filter plates
Fittings
Pipelines
Coil bodies

Kynar, Tecaflon

1.75

50

140

2100

8

NA

PCTFE

Polychlorotrifluoroethylene

White

Dimensionally stable, rigid, and resistant
to cold flow, very low gas permeation and outgassing, near zero moisture absorption, excellent chemical resistance, radiation resistance

Cryogenic and chemical processing components
Seals and gaskets
Aerospace valve seats, pump parts, impellers,
diaphragms, and plugs
Laboratory instruments
Nuclear service/high radiation exposure
Liquid oxygen and liquid nitrogen valve linings

Kel-F

2.15

36

195

1400

2.6

NA

PI

Polyimide

Brown

Non melting high temperature polyimide, High heat resistance, good cryogenic properties, excellent electrical insulation, good machinability, inherently flame retardant

Automotive and aerospace - machined parts
Electronic and solar - films

Kapton

1.34

116

300

3600

3.8

Graphite, MoS2, PTFE

PEEK

Polyetheretherketone

Light Brown

Strength, dimension stability, heat resistance, chemical resistance, wear resistance, light weight

Aerospace - lightweight components for metal replacement
Electronical industry: insulators, connectors and wafer-carrier
Mechanical engineering: gear wheels, sliding elements, compressor- and pump-components, drives, bushings, valves and rollers
Automotive industry: clutch and gearbox components and turbocharger impeller
Conveyor technics: guidance, strokes, rollers, grippers, and valves
Medical industry: parts for surgical instruments and short term implants
Food industry: valves, blenders, strippers, dosing systems and kneaders
Oil- and gas industry: drill heads, sealings and sensors

Victrex, Ketaspire

1.3

110

250

4000

3.1

Glass, Carbon, Graphite, PTFE

PTFE

Polytetrafluoroethylene

Waxy white

Extremely high chemical resistance, very good temperature resistance, very low coefficient of friction, low dielectric constant, flame resistance

Aerospace - radar applications
Automotive - wear strips and bands
Chemical plant engineering (valves, pump components, fittings, hopper)
Food and pharmaceutical industries
Sliding applications under high chemical stress

Teflon

2.25

25

260

550

2.1

Glass, Carbon, Bronze


Read More

1. High Performance Polymers in Railway Applications

2. Polymer Sealing Solutions – High Performance Seals, Valves, and Seats

3. Polymer Wear Plates - Grade Selection and Key Advantages