PTFE Seals

General Information

The Eurosealings spring energized PTFE seal is the newest generation of spring actuated Teflon seals. These seals consist of a special precision jacket/lip made of Teflon (or other high performance polymers) and a corrosion resistant stainless steel spring.

In this combination, the spring is forcing the seal lips against the gland and the rod walls. The pressure assists the spring force.

The spring compensates the lip wear, hardware tolerances, eccentricities and provides permanent resilience to the seal lips. The Eurosealings design with sealing lip and spring arrangement guarantees more leakage protection than conventional lip seals.

More than 50 different PTFE compounds (and other high performance polymers) are available or can be composed for jacket fabrication within a very short time.

The standard designs cover radial and axial seals for dynamic as well as static applications.

In addition to standard designs, we are also able to produce designs made to specification for special applications (silicone filled, sanitary seals, ultra low friction seals, etc.).

A wide variety of materials, dimensions, and designs provide the opportunity to solve difficult sealing problems.

Radial Seals

(Piston- and Rod Seals)

Type 400
Some Design Variations of Type 400
Type 401
sharp scraper-lip on the inside-diameter
Type 402
sharp scraper-lip on the outside-diameter
Type 4VS
chamfered seal-lips
Type 414
type 400 with flange
Type 4FM
with silicone filled spring cavity for food processing and sanitary applications FDA-approved

 

Type 103
Some Design Variations of Type 103
Type 113
sharp scraper-lip on the inside-diameter
Type 123
sharp scraper-lip on the outside-diameter
Type 103H
extended seal-back for high pressure
Type 143
type 103 with flange

In addition to these listed standard sizes, we can ship special designs in each sizes and cross sections. We will make recommendations by our Engineering Department.

Axial Seals

Face Seals for Static and Rotary Service

For Internal Pressure
Typ 403
Dynamic and static applications. Low seal friction.
Typ 304
Dynamic and static applications. Higher spring force. For higher pressure.
Typ 1100
Static and slow dynamic service. High loaded spring for lowest leakage and low temperatures.
Typ 2100
Static and slow dynamic service. Extra large deflection range of spring.

For External Pressure/Vacuum
Typ 404
Dynamic and static applications. Low seal friction.
Typ 314
Dynamic and static applications. Higher spring force. For higher pressure.
Typ 1101
Static and slow dynamic service. High loaded spring for lowest leakage and low temperatures. Good vacuum seal, low gas permeability.

In addition to these listed standard sizes, we can ship special designs in each sizes and cross sections. Please send us back the application data form. We will make recommendations by our Engineering Department.

Seals selection and operation range

The wide variety of types provide the opportunity to meet all sealing requirements for axial and radial seals. Not all maximum stresses can be applied to the seal at one time.

The variety of designs, jacket and spring materials, together with several springs and dimensions allow sealing applications within the following working ranges:

• Temperatures from -250°C to +316°C
• For rotation and reciprocating movement up to 5 m/s
• For static applications up to 3500 bar pressure
• For dynamic applications up to 550 bar pressure
• Universal chemical-resistant
• For vacuum and UHV applications
• Diameter from 2 mm up to 3000 mm

Materials

Seal Jacket Materials:

Material Description Ordering Code Relative Wear Resistance 1=low, 9=high Temperature Range Degrees [°C] PTFE-virgin Recommended for low to moderate dynamic or static service. Low gas permeability. FDA approved. Good cryogenic (low temperature) properties. 01 3 -250 ... +205°C PTFE-virgin modified Recommended for low to moderate dynamic or static service. Lowest gas permeability. FDA approved. Higher creep resistance, very high chemical resistance. 1X 3 -250 ... +215°C PTFE-reinforced with Carbon and Graphite Very good universal properties for higher temperatures and resistance to wear. Especially suitable class="table" for hot water and steam service as well as for poor lubrications. 03 8 -130 ... +290°C PTFE-filled with Graphite Excellent general purpose material with low friction, good wear and heat resistance. Non-abrasive. Good for water service, dry or poorly lubricated applications. 12 7 -130 ... +290°C PTFE- filled with Glass fiber and MoS2 Extremely abrasion resistant, recommended for high pressure hydraulic, water and steam service. At high speeds and with soft metal surfaces may be abrasive wear possible. 06 9 -155 ... +290°C PTFE-reinforced with special filler Superior wear and heat resistance. May also be used for soft metals. No abrasive wear. Recommended for static and dynamic service, high temperatures and high speeds. 10 8 -155 ... +316°C UHMW-PE modified Excellent wear resistant, but limited chemical and heat resistance. Especially suitable class="table" for abrasive media and water based liquids. FDA approved. 08 9 -240 ... +104°C

Additional sealing materials in stock. We can compound seal jacket materials for optimal performance. This is why we are able to offer a wide variety of sealing materials. We can offer more than 50 different compounds. Only the most frequently used compounds have been listed above.

Spring Energizer Materials:

Ordering Code Description UNS No. Standard spring material C 301 Stainless Steel (1.4310)   Additionally available spring materials E Elgiloy (2.4711) R 30003 I Inconel (2.4669) N 07750 R Hastelloy (2.4602) N 06022 For other Stainless Steels, such as 316, 302, 17-7PH ask Technical Service

Hardware and groove dimensions

Radial Seals:

For Types 400, 401, 402, 4VS, 4FM, RP, RS, 103, 113, 123, 103H, etc.

Rod Seals:

For rod seals use the dimension B for Nominaldimension.
Dimension B = rod diameter

Piston Seals:

For piston seals use the dimension A for Nominaldimension.
Dimension A = cylinderbore diameter

Groove Dimensions - Radial Seals:

Nominal cross section A mm B mm G + 0,25 mm T + 0,05 mm R mm E max mm from to from to 1/16’’ 4,4 150 1,3 150 2,4 1,42 0,2 0,1 3/32’’ 8 300 3,5 300 3,6 2,26 0,2 0,13 1/8’’ 12,5 500 6,5 500 4,7 3,07 0,25 0,13 3/16’’ 22 800 12,5 800 7,1 4,72 0,3 0,15 1/4’’ 37 1200 25 1200 9,5 6,05 0,3 0,2 3/8’’ 95 3000 75 3000 15 9,5 0,4 0,3 1/2’’ 175 3000 150 3000 18 12,7 0,5 0,4 3/4’’ 340 3000 300 3000 25 19,05 0,8 0,5

We can also ship special sizes, special designs, each diameter and dimensions between 2 mm and 2000 mm diameter.

Axial Seals:

For Types 403, 304, 1100 and 2100 for internal pressure, and Types 404, 314, 1101 for external pressure and vacuum.

Seals for internal pressure use the outside diameter OD as Nominal diameter. (Nominal diameter = groove outside diameter).

Seals for external pressure and vacuum use the inside diameter ID as Nominal diameter. (Nominal diameter = groove inside diameter).

Groove Dimensions - Axial Seals:

Nominal cross section ID mm - 0,25 AD mm + 0,25 G + 0,25 mm T + 0,05 mm R mm E max mm from to from to 1/16’’ 5 150 10 150 2,4 1,42 0,25 0,1 3/32’’ 8 300 14 300 3,6 2,26 0,25 0,13 1/8’’ 12 500 18 500 4,7 3,07 0,4 0,13 3/16’’ 25 800 35 800 7,1 4,72 0,6 0,15 1/4’’ 55 1200 70 1200 9,5 6,05 0,6 0,2 3/8’’ 120 3000 150 3000 15 9,5 0,6 0,3 1/2’’ 215 3000 250 3000 18 12,7 0,8 0,4 3/4’’ 300 3000 350 3000 25 19,05 1,0 0,5

We can also ship special sizes, special designs, each diameter and dimensions between 2 mm and 2000 mm diameter.

Kalrez® and Viton® are registered trademarks of DuPont Dow Elastomers.

Groove dimensions PTFE seals type 413 and 143

Radial and Axial Dimension

The seals type 414 and 143 respectively are designed with flange for the axial fixation and/or securing of rotation with rotary seals. Other dimensions are possible as well.

Groove dimensions seals with flange

Profil T D -0.25 C +0.15 E max F +0.1 G +0.25 H -0.1 3/32" 2.25 3.4 5.2 0.1 0.25 3.6 0.65 1/8" 3.1 5.0 6.9 0.1 0.35 4.7 0.75 3/16" 4.75 7.1 10.1 0.15 0.40 7.1 1.00 1/4" 6.1 9.9 13.2 0.2 0.50 9.5 1.25 3/8" 9.5+/-0.05 15.0 20.0 0.3 0.80 15.0 2.50 1/2" 12.5+/-0.1 20.0 26.0 0.4 1.00 18.0 3.00

Dimension B will be specified by the customer

Quality of finish for rotary seals

The sealing surface should possess a material portion M_r (in former times bearing portion tp) of approx. 50 to 70% measured in a cutting depth c = 0.25 x R_z

Application Media to be sealed   Gas- and cryogentechnology Liquids Dynamic 0.1 ... 0.8 µm Ra 0.2 ... 0.4 µm Ra Static 0.3 ... 0.8 µm Ra 0.4 ... 1.6 µm Surfaces and flanks without sealing function approx. 0.4 ... 6.3 µm Ra (depending on dimension)

Hardness of finish for rotary seals

With rotary sealing cases we recommend a hardness of finish of at least 55 HRC.
The depth of hardness should amount at least to 0.4 - 0.4 mm.

Surface finish

(Rod and housing)

The life expectancy of the seal and the sealing quality is also directly dependent upon the quality of the sealing surface.

We recommend the following surface finish.

Applications Sealing Medium Gases and Cryogenics Fluids Dynamic 0,2 ... 0,3 µm Ra (N3 ... N4) 0,2 ... 0,4 µm (N3 ... N5) Static 0,3 ... 0,8 µm Ra (N4 ... N6) 0,4 ... 1,6 µm Ra (N5 ... N7) Other non-sealing surfaces approximately 0,4 ... 6,3 µm Ra (depending on dimension

Sterilisable seals and integral piston seals

Especially for filling machines and aseptic applications

Universal chemical-resistant and elastic PTFE-seals for especially aggressive media, also suited for sterilisable and FDA-approved sealing elements for food and pharmaceutical drugs.

The material characteristics of high grade fluorsynthetic materials, such as PTFE, PFA, PCTFE, etc. and acid-resistant spring steel are combined in these spring-elastic sealing elements in an ideal manner.
The spring made of corrosion-resistant steel (e.g. 1.4568 Hastelloy C, etc.) embedded high and durable alsticity, sets off cold flow and wear of the sealing lip and effects defined low sealing forces.
Depending on material selection these sealing elements are universally chemical-resistant. These sealing elements were developed, above all, for sealing of especially aggresive media and the sterilisable seals for foodstuff and pharmaceutical drugs filling systems.

The advantages of Eurosealings seals:

• Universal chemical-resistant
• Durable elasticity because of an integrated stainless steel spring
• Sterilisable for foodstuff or pharmaceutical applications
• Capsulated or totally sealed stainless steel spring
• Highest wear resistance and lowest friction forces
• Suitable class="table" for high and low temperatures (-100°C bis +310°C)
• Seals or integral piston seals with durable elastic seal lips
• Made of FDA (BGA/USDA) approved materials (PTFE or UHMW-PE) or made of especially wear-resistant PTFE-Compounds

The shown designs and types are only examples for the variety of possibilities, which can be realised with this variable modular system.
Send us your drawing/sketch, installation conditions and dimensions (groove dimensions, cylinder-diameter, rod-diameter, etc.), materials and hardness of the mating surfaces as well as the needed quantities.
We will submit an assembly proposal and an offer.

Series 400 Available in PTFE or also FDA approved UHMW-ployethylene. Type 400 is characterized by its easy installation and extremely high wear resistance. Series 4FM This type is based on the series 400. The spring cavity is filled with FDA approved silicone. This prevents the product from settling in the groove or bacteria from entering the spring clearances. Series 4S In this unique design the inseted stainless steel spring is totally protected by the PTFE-coating on the media side. Applications with high temperatures, defined friction forces and very elastic behaviour are characteristics for this sealing element. Even extra-pure media can be conveyed or sealed off with this seal, where the medium may not get into contact with the metal. This type is FDA approved and admitted for food and pharmaceutical drugs. Series JS The series JS is a variant of the RS type, but with a machined synthetic material jacket. Available in all sizes without additional costs. Mostly for small quantities. The jacket is available in PTFE or also in FDA approved UHMW-polyethylene. Special with a totally capsulated stainless steel spring Diaphragm-seal with a one-sided flexible membran to separate and handling aggresive fluids. A complete element for small metering pumps and valves.

A clean and economical solution for your sealing problem

The metering piston with a completely smooth surface, elastic seal lips, sterilisable, as a single one-piece element for metering, sealing and displacing, with an integrated bearing, maufactured of FDA approved polymer materials, provide your technical advance.
The smooth non-split surface and the elastic seal edges/scraper lips on the front and on the back of the piston prevent the products from settling in. PTFE materials with lowest friction coefficient and FDA-admission as well as especially wear-resistant compounds of physiological undaubtful admixtures provide a reliable tightness and a high wear life.

Assembled on the piston bar with a central thread or a flange plate. Assembled with a screw cap or use a flange with several bore holes.

Seal numbering system

Seal Numbering System and Part Number Examples

In general the following data suffice for seal definition and ordering:

1) Type	s. Standard-Radial and Standard-Axial Seals
2) Nominal Diameter	Rod-, shaft-, cylinder-, bore-diameter or the groove and hardware dimensions
3) Nominal Cross Section	1/16’’, 3/32’’, 1/8’’, 3/16’’, 1/4’’, 3/8’’, 1/2’’, 3/4’’ or the groove and hardware dimensions
4) Seal Jacket Material	s. Materials
5) Spring Energizer Material	s. Materials

Seal Numbering System/Part Number Examples

400 402 103	B 50,0 A 250,0 B 25,0	1/8" 3/16" 1/8"	01 12 10	C C E
Type	Nominal Diameter	Nominal Cross Section	Seal Jacket Material	Spring Energizer Material

For special designs suffice the groove or hardware dimensions. For example:

103	B 250,0 x 270,0 x 15	06	E
Type	Groove Dimension	Seal Jacket Material	Spring Energizer Material

Information for installation

The installation in split grooves is the easiest way. Seals can usually be installed in partially closed grooves (with retainer) without any problems. Depending on diameters and cross sections, the type 103 seals can be installed in closed (nonsplit design) grooves. In such cases, we recommend contacting our Technical Service.

We will help you to work out the best solution for your assembly problem.

The mating surfaces should be smooth, free of burrs and sharp edges. Lead-in chamfers should be available for shafts and cylinders. When assembling over grooves and threads, a sleeve should be used to protect the seal. Light oiling or greasing makes the assembly easier.

All recommendations and data provided in this catalogue are based on the experience gained over decades of using such seals. Unknown factors and special conditions may restrict the generally valid promises. We are not able to guarantee every individual application. We suggest tests with samples. Our application engineers are always at your disposal for design and consultation. Don`t hesitate to use our experience.

For additional questions, please contact our Technical Service