Diflon PTFE Lined Valves Pipe

Dioxide Pacific is the Australia and New Zealand distributor for Diflon TECHNOLOGY srl.  Diflon specializes in manufacture of PTFE and PFA lined pipe, valves and tanks. Many years of successful operation have culminated in a complete supply range of pipes, fittings, flexible hoses, expansion joints, columns and tanks in PTFE lined metal and supply of gaskets and other pieces in PTFE.


DIFLINE Carbon steel or stainless steel pipes and fittings with virgin PTFE internal coating. The PTFE coating covers all metal internal parts up to the seal face of the flange, thereby preventing chemical contact with metal and avoiding corrosion. manufactured according to DIN 2848 and the 97/23/CE PED certification. DIFLINE pipes are self-supporting and do not require racking and bracketing that is typically required for plastic pipework. Service temperatures -30°/+200°C. PTFE is permeable to chlorine gas and it is not compatible with alkali metals and fluorine gas.

  • washing
  • distillation or rectification
  • absorption columns for HCl/HBr
  • liquid extraction
  • reactors
  • storage tanks

Temperature range: normally -10°C to +200°C. Maximum operating pressure = 6 Bar.
Special solutions can be provided for vacuum applications. TANKSLINE lining is virgin PTFE processed to guarantee the PTFE is hydrophobic and dimensionally stable. PTFE linings are available in thicknesses from 3 to 5 mm. PTFE is known to be non-stick, ensuring high resistance to fouling, eliminating or reducing downtime for cleaning.
Columns and tank diameters:  DN 300 to DN2000 in flanged sections up to 2 m in height, flat or taper end plates with welded or machined nozzles and a range of PTFE internals such as distributors, supports, rings, diffusers, suction tubes, etc. Please see the TANKSLINE catalogue for details of the full range. The PTFE lining can be repaired if it becomes damaged.

The FLEXLINE range consists of PTFE tube with external stainless steel sheath; PTFE or PFA pipes with thin walls; rubber and pure silicone multi-layer hose. Hose can be supplied with any kind of fitting to suit your requirements.

PTFE, Steel, Rubber-to-seal, flanged and machined expansion joints

Expansion joints are used to join tanks, machinery, pumps and pipework to minimize vibration and take care of expansion caused by thermal expansion and contraction, pressure changes, external movement and pipeline weight.

Safety Spray Shields are designed to temporarily contain hazardous leaks and sprays from plant equipment connections. Leaks can occur on piping systems conveying chemicals, high temperature fluids, and steam, which can harm workers, nearby equipment, and the environment. Leaks of flammables, such as fuel or oil, can create fire and explosion hazards.
Safety Spray Shields help meet regulatory standards set by agencies such as OSHA, EPA, MSHA, SOLAS, ABS, and DNV, and are now required by some insurance companies.
Constructed of durable fabrics that are chemical, UV, and weather resistant, our Shields are available in Polypropylene, PVC, and Polyethylene. Solid styles contain a pH indicating patch which signals a leak by immediately changing color towards red if acidic or towards green if an alkali. The patch is replaceable which allows reuse of the shield.
Our Shields are ready to install quickly and simply by one person with the equipped hook and loop fasteners and drawcord.
We offer Shields for all sizes and ratings, both standard, non-standard, and metric(DN).

Shields and covers can be used for the following equipment:

  • Hose
  • Pipe
  • Flow Indicators
  • Sight Glasses
  • Fittings
  • Couplings
  • Marine Roll Shields
  • Insulated Blankets
  • Fire Extinguishers
  • Tarps
  • Curtains
  • Customs

How to order

  • Flanges: specify size and rating.
  • Valves: specify size, rating, type, model/manufacturer, and connection-flanged, socket weld, or threaded.
  • Expansions joints: specify size, model/manufacturer, number of convolutions, or overall length.
  • All others: contact us.

Diflon offers gasket cutting, a large inventory of standard flat gaskets and special gaskets manufactured to your requirements. Diflon offers sheet gasket material in size 1,500 x 1,500 mm in thicknesses of 1, 2 and 3 mm.

DIFLEX is resistant to almost all chemicals, pH 0-14, acid and strong alkali, solvents, chlorine, catalyzers, liquid gas, vapour, diathermal oils, food, pharmaceutical and petrochemical products, etc.; the only exceptions are melt alkali metals and fluorinated products. DIFLEX is recommended for use in the chemical, petrochemical, pharmaceutical, food, cryogenic industries, etc.

  • DIFLEX is resistant to high levels of compression, maintaining its elasticity
  • DIFLEX does not absorb moisture
  • DIFLEX does not stick both at high and low temperatures
  • DIFLEX is weatherproof and does not age even in a marine environment
  • DIFLEX is completely acid proof
  • DIFLEX is non toxic

DIFLEX gaskets were first used in 1993 by major engineering companies. DIFLEX gaskets can be used for continuous service at a temperature range of -150°C to +260°C and also under high pressure. Diflex gaskets are also available in welded versions, even for diameters exceeding 3 m, or according to the your specifications.

OCEAN flat strip for gaskets is 100% pure PTFE material processed into a fibrous molecular structure .

OCEAN properties:

  • High plastic deformation with reduced cold creep; ideal even for solving complex sealing applications quickly. When pressure is applied, OCEAN is transformed into a thin tape, filling all micro-cavities in the seats of seals. (See table.)
  • Resistant to all chemicals except for some fluoridated compounds and molten alkali metals.
  • Does not contaminate the media with which it comes into contact; it does not release color particles and is non-toxic.
  • We can provide OCEAN to any size you require.
  • Making a seal from the OCEAN flat strip is an extremely simple task. The adhesive side of the strip has a protective band. To apply the strip, first remove this strip and press against the surface to be sealed. Then the two ends of the strip are joined, one on the top of the other. Alternatively,  you can cut diagonally and join end to end if the tightening pressure is low. A standard flat gasket is the result.

OCEAN Sheets

ePTFE-BIAX – Gasket Sheets consist of pure, expanded PTFE. In the manufacturing process, a multi-directional fibrous texture is produced, which gives the gasket sheets their special properties. OCEAN sheet material has very low compression and low dimensional change even under extreme conditions of high surface pressure and high temperature (especially compared to material from other manufacturers).

ePTFE-BIAX – Gasket Sheets is especially designed to conform to the highest safety requirements such as in critical flange joints in oxygen pipelines.

Braid/stuffing box Packing products are used by industry to insulate shafts, rods and seats to prevent escape of gas or fluids. The main fields of application are:

  • static seals (covers, frames, furnace doors, boilers);
  • stem seals (valves);
  • moving shaft seals (plunger pumps);
  • rotating shafts (centrifugal pum-ps, mixers, stirrers).


When selecting the type of braid/stuffing box Packing required, we recommend assessing:

  • Flexibility, to avoid stretching and twisting due to deformation in the Packing structure when laid in rings;
  • Elasticity and elastic return, to guarantee tightness under pressure;
  • homogeneity, acting as a guarantee of efficient service and longer life;
  • Compact external surfaces, guaranteeing tightness while avoiding excessive tightening pressure and possible wear to the shaft;
  • Impregnation to the heart (also known as yarn-by-yarn impregnation), offering guaranteed tightness to improve efficiency.


Braid/stuffing box Packing products have different components to suit their different applications. The main components are:

  • graphite fibres (providing extra chemical and thermal resistance);
  • insulating glass and ceramic fibres (generally used for static thermo-resistant seals);
  • vegetal fibres, such as cotton, linen, ramie fibre and hemp (especially suited to applications with cold water and where hard-wearing qualities are required);
  • synthetic fibres, such as PTFE, polyester, aramidic and acrylic fibres (suitable for producing Packing with high resistance to chemicals and corrosive agents);
  • metals, such as stainless steel, copper and inconel (used to strengthen the Packing and thus increase its mechanical strength at high temperatures and pressures);
  • lubricants and binders, essential when using Packing, as these must not react with the fluid or corrode the metals surrounding the Packing and also eliminate friction. This category includes mineral, vegetal and synthetic oils and greases (for universal use), dry or dispersed graphites (for external treatment with excellent self-lubrication and anti-friction properties), dispersed (for lubrication and anti-friction treatment on Packing coming into contact with chemicals and corrosive agents) and Molybdenum Disulphide MoS2 (used in external treatments with particular self-lubricant and anti-corrosive properties).


Polytetrafluoroethylene (PTFE) is a tetrafluoroethylene polymer featuring a unique combination of physical-chemical features that make it different from any other plastic material. The main features of PTFE are:

  • extreme chemical inertness
  • excellent heat resistance
  • optimum dielectric properties
  • not hygroscopic and maximum resistance against solvents
  • optimum resistance to ageing
  • self-lubricating properties and minimum friction coefficient

Chemical Properties

PTFE withstands virtually all chemical reactants. It is only attacked by elemental alkali metals, chlorotrifluorides and elemental fluorine at high pressure and high temperature. PTFE is indifferent to all solvents up to 300°C. It can only be swelled and melt by some highly fluorinated oils at temperatures around the crystalline melting point.

Thermal properties

PTFE has a low heat transmission factor and can be therefore considered a thermoinsulating material. It also shows flame-retardant properties and is stable at 260°C for an indefinite length of time.

Electrical properties

PTFE has optimum dielectric properties within a vast range of temperatures and frequencies. As water absorption is virtually nonexistent, these properties are maintained even after a prolonged exposure to weather agents. Electric strength is practically not influenced by the operating temperature. The resistance to arcing of PTFE is considerable and the spark does not generate carbon residues but only non-conductive vapors. The other electric properties (dielectric constant, surface resistivity, volume resistivity, power factor, etc.) show very interesting values.

Filled PTFE

The above-mentioned properties make PTFE the material of choice for difficult chemical applications. However, there are specific applications which claim for higher product performance. In this case, filled PTFE grades are employed. In this case, PTFE is filled with  special additives in powder form, such as glass fiber, carbon, graphite, molybdenum disulphide, bronze, ceramic powder, and even mixes of two or more fillers. According to the filler type and quantity, it is possible to:

  • increase compressive strength
  • increase wear resistance
  • reduce the thermal expansion coefficient
  • vary volume and surface resistivity
  • increase hardness.

PFA coatings

PerFluoroAlkoxy alkanes (PFA) is a fluoropolymer. It is produced by copolymerization of tetraefluoroethylene (C2F4) and perfluoroethers (CF2F3ORf). In terms of its properties, this polymer is similar to polytetrafluoroethylene (PTFE). The big difference is that the alkoxy substituents allow the polymer to be melt-processed.
PFA is melt-processable by conventional thermoplastic processing methods, including injection, transfer, blow, and compression molding and by extrusion.
It is a relatively soft thermoplastic with lower tensile strength and creep resistance than many other engineering plastics. It is chemically inert and has a low dielectric constant over a wide frequency range.

PFA is used when extended service is required in hostile environments involving chemical, thermal, and mechanical stress. PFA offers high melt strength, stability at high processing temperatures, excellent crack and stress resistance, a low coefficient of friction.
It has high resistance to creep and retention of properties after service at 260°C (500°F). PFA also meets FDA 21CFR.177.1550.

PFA has high transparency (with good transmittance of Ultraviolet and visible wavelengths.) It has long term weatherability and excellent resistance to ozone, sunlight and weather.
Important applications are linings for pipe and chemical processing equipment, roll covers, and several wire and cable applications, including aircraft wire, plenum cable, fire alarm cable, and well logging cable.

PFA – Perfluoroalkoxy – TYPICAL PROPERTIES

Property Value Units Method
Tensile Strength, 73°F 4060 – 4500
28 to 31
Elongation, 73°F 260 – 300 %
Flexural Strength, 73°F No break at flexure D 790
Impact Strength, Izod No break
Compressive Stress at 1% deformation, MPa D 695
Yield Strength
At 23 deg C
Density (as polymerized) 2.12 to 2.17 gm/cu.cm
Coefficient of Linear Expansion
20 to 100 deg C
12 x 10-5 K-1
Melting Point 487 – 540
253 – 282
deg F
deg C
Thermal Conductivity 1.450.209 Btu/hr-.ft-deg F
W/m/deg K
ASTM C 177
Specific Heat 0.25
Btu/lb/deg F
kJ/Kg/deg K
Heat Distortion Temperature,
66 lb/sq.in (0.455 MPa)
158 to 171
70 – 77
deg F
deg C
D 648
Service Temperature -418 to 403
-250 to 206
deg F
deg C
Processing Temperature 698 – 743
370 – 395
deg F
deg C
Dielectric Strength,
short time, 0.080”
MV m-1
Surface Arc-Resistance >300 (does not track) sec D 495
Volume Resistivity, dry, @ 50% RH >1018 ohm-cm D 257
Surface Resistivity, @ 100% RH 1016 ohm/sq.
Dielectric Constant 1kHz to 1GHz 2.06 ? D150-81
Dielectric Strength 78.8* kV mm-1 D149
Dissipation Factor @ 60 Hz – 1 MHz <0.0001 D150-81
Refractive Index 1.344 nD 25 D 542
Water Absorption <0.1 % D570-81
Flame Rating+ VE-0 UL-94
Limiting Oxygen Index 95 % Oxygen D 2863
Resistance to Weathering Excellent
Specific Gravity 2.12-2.17 D792-66 (1979)
Static coefficient of friction 0.05-0.08
CO2 Permeability 273 Ng cm m-2 s-1
O2 Permeability 637 Ng cm m-2 s-1
N2 Permeability 91 Ng cm m-2 s-1

FluoroSeal®, Non-Lubricated, Sleeved Plug Valves incorporate the latest PTFE fluorocarbon seat design. You can expect low maintenance and trouble-free operation. High integrity bubble-tight sealing is provided inline and to atmosphere.

The FluoroSeal® internal body configuration has been designed to totally contain all the edges of the PTFE sleeve at the top, bottom, and around the entire port opening adjacent to the waterway. Any tendency of the sleeve to grow is accommodated by relief recesses designed for this purpose and positioned at 90 degrees to the body port openings. The port-defining metal lips protect the PTFE sleeve from erosion and any possibility of sleeve rotation within the body.
The waterway in the body has been designed with a contour providing a flow path that assures minimum flow turbulence characteristics. The critical sealing areas around the top and bottom of the sleeve and around the body port openings are maintained by means of an adjustable tapered plug compressing the PTFE sleeve over raised ribs. The PTFE top seal components are similarly contained and protected from damage. A counter bore is provided at the top of the metal body to encapsulate the outside diameter of the formed PTFE diaphragm in conjunction with the formed metal diaphragm and to protect it. The inside diameter of the formed PTFE diaphragm, adjacent to the plug stem, is also contained by means of a unique lip design of the formed metal diaphragm preventing extrusion and maintaining the stem seal throughout variable service conditions. This uniquely formed metal diaphragm also provides a positive electrical ground between the plug and body, eliminating the need for an extra component to fulfill this function as is the case for other valve manufacturers’ designs.

Available in the following configurations:

2/2 way Metal Diaphragm valve with plastic or metal handwheel

2/2 way Metal Diaphragm valve with plastic pneumatic actuator (NC) or (NO) double acting

Butterfly Valve Features:

  • ISO 5211 mounting flange allows for accurate and direct mounting of actuators
  • Extended neck provides adequate distance for piping insulation.
  • Duplex stainless steel disc/shaft assembly is M-PTFE molded with fully machined sealing surfaces. Ball & Socket disc-hub design. Three TFE coated radial bearings keep disc/shaft assembly stable by eliminating disc deflection and actuation side loads.
  • The shaft is carried in triple, maintenance-free bearings.
  • M-PTFE liner is third generation TFE with improved permeation, porosity and cold flow characteristics. Fully machined conical sealing surfaces eliminate hard transitions to avoid cycle damage and improve performance.
  • Upper & lower stems seals are designed for the most critical services.
    Independent, triple sealing is dynamically loaded for added assurance.
  • Unique convex body channel optimizes sealing and reduces adverse elastomer loading on liner.
  • EBRO liners are isostatically molded to reduce porosity and laminations found in compression molding. All operational areas are machined, and have a minimum thickness of 3mm.
  • Liner extends into the stem hubs for added protection. Stem hub areas are isostatically molded solid and then machined, resulting in high quality, stressed-free sealing surfaces.
  • Liners are designed, molded and machined to eliminate problems associated with cold flow and cycle damage. The concave design of the liner in the disc sealing areas reduces harmful interference and rubbing. The contoured design of the liner at the flange connection removes hard 90 degree edges and reduces potential cold flow problems. Combined with state-of-art M-PTFE material, the EBRO liner design is unsurpassed in performance and dependability

PFA Lined ball valves in the configurations: 3 way ball valve; fully lined tank drain valve; full port valve

Stainless steel ball valves in the following configurations:

710N – Floating wafer forged ball valve

• ANSI 150-600
• PN 16-100
• PN 6, PN 10, PN 25 available on request

710F – Floating wafer cast ball valve

• ANSI 150-300
• PN 16-40
• PN 6, PN 10, PN 25 available on request

720N – Threaded floating 2 pieces ball valve forged body full bore

Rating: 800 – 3000 P.s.i.
Available features: Nipples with SW ends; Nipples with BW ends; Nipples with plain ends; Gas/Npt male/female thread; Locking device; ISO top mounting on request.

721N – Threaded floating 2 pieces ball valve forged body reduced bore

Rating: 800 – 3000 P.s.i.
Available features: Nipples with SW ends; Nipples with BW ends; Nipples with plain ends; Gas/Npt male/female thread; Locking device; ISO top mounting on request.

750F – Floating split body cast ball valve full bore

• ANSI 150-300
• PN 16-40
• UNI 558-1 – ISO 14313
• PN 6, PN 10, PN 25 available on request

760F – Floating split body cast ball valve reduced bore

• ANSI 150-300
• PN 16-40
• UNI 558-1 – ISO 14313
• PN 6, PN 10, PN 25 available on request

750N – Floating split body forged ball valve full bore

• ANSI 150-600
• PN 16-40
• PN 6, PN 10, PN 25 available on request

760N – Floating split body forged ball valve reduced bore

• ANSI 150-600
• PN 16-40
• PN 6, PN 10, PN 25 available on request

For a quotation on any of the Diflon product range please contact us.