Technical information Technical informationContent · 6 7 O-RINGS O-RINGS Technical information Technical information O-rings standards Function and use O-rings are sealing elements

O-RINGS

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32O-RINGS O-RINGS

Technical information Technical informationContent

1. INTRODUCTIONBasic characteristics 4Materials used, their properties 4 – 5Fabrication tolerance, standards 5 – 6Function and use 6Sealing joint, material hardness 7Installation instructions 8

2. DETERMINING THE RIGHT O-RING SIZEDeterming the thickness (d2) and the inner diameter (d1) 9Detailed groove construction – basic notions 10

3. STATIC SEALING – RADIAL DIMENSIONDeterming the dimensions – rectangular groove 10Tolerance, roughness, max. sealing joint 11

4. STATIC SEALING – AXIAL DIMENSIONDeterming the dimensions – rectangular groove 12Determing the dimensions – trapezoidal groove 12Determing the dimensions – triangular groove 13

5. DYNAMIC SEALINGDeterming the dimensions – rectangular groove 14Roughness tolerance 15PTFE O-rings 16O-rings for vacuum sealing 16Cords 17Assembly boxes for bonding of O-rings 17Dimension series of NBR O-rings 18 – 50Dimension series of FPM O-rings 51 – 81X-rings 82

Range of products


54O-RINGS O-RINGS

Technical information Technical information

1. INTRODUCTION

O-rings are highly precise circular sealing elements, which are efficient and economical at the same time and can be used for a wide range of both static and dynamic applications. O-rings are vulcanized in moulds and, due to their symmetric shape, they can be used as single as well as double seals. The size of an O-ring is defined by its inner diameter d1 x ring thickness d2 (figure 1). Sizes, materials, hardness and installing dimensions are defined by the DIN 3770 or ISO 3601 standard. All dimensions are given in millimetres.

d1 = inner diameter (mm)d2 = O-ring thickness (mm)

Material groups

The following table gives an overview of material groups of elastomeric substances with the option of choosing the material hardness (table 1). The following factors influence the decision on material and hardness: size of sealing joint, temperature, pressure, chemical exposure.

For most applications, the standard quality NBR 70 Sh is sufficient. For higher temperatures and chemical exposures, standard quality Viton FPM 80 Sh can be used.

Material hardness is given on the “Shore” or “IRHD” scales.

Please inquire for non-standard materials such as polyurethane, KALREZ, fluorosilicone, NEOPRENE -they can be delivered after the manufacturing plant is consulted.

OK NBR 70 35 x 3

d1 d2type material hardness

dimensions

Properties of selected materials

1 - excellent2 - very good3 - good4 - applicable5 - less applicable6 - not applicableX - not measured for this material type

Production tolerance of O-rings

The following values show tolerances for Nitrile-butadiene-rubber compound with 70 Shore or 73 IRHD hardness. Even with identical moulds, other compounds have different cross-sections and higher tolerances. It is always possible to manufacture special moulds according to your specifications.

O-RINGS MATERIAL (table 1)

Code Trade name Hardness Shore ANB, NBR Nitrile-butadiene-rubber 55, 60, 70, 75, 80, 90FP, FPM Fluorine rubber (Viton) 60, 70, 75, 80, 90SI Silicone rubber 50, 60, 70, 80EP, EPDM Ethylene-propylene rubber 75, 80, 85CR Chloroprene rubber 50, 60, 70, 90NR Natural rubber 45, 65, 80BU Butyl rubber 45, 65, 80CSM Chlorsulphonated polyethylene rubber (Hypalon) 65, 75PTFE Polytetrafluoroethylene (Teflon) -

HARDNESS OF O-RINGS (table 2)

Shore A hardness 60 70 80 90IRHD hardness 63 79 83 92Tolerance ± 5Tested according to DIN 53505 or 53519

PROPERTIES OF SELECTED MATERIALS (table 3)

Material type NBR FP SI EPDM CR NR BU CSM PTFETensile strength without support 5 5 6 5 3 1 4 5 1Tensile strength with support 2 3 4 3 2 1 3 3 1Elongation at break 2 3 4 3 2 1 2 3 3Reverse elasticity 3 5 3 3 3 2 6 4 xConstant resistance 2 4 5 3 2 2 3 3 3Tensile resistance 3 3 6 3 2 2 3 4 2Resistance to electrical flow 4 4 1 2 3 1 2 4 1Resistance to strain ageing 3 1 1 1 2 3 2 2 1Resistance to ozone 3 1 1 1 2 4 2 2 1Resistance to fuel 1 1 5 5 2 6 6 2 1Resistance to oil 1 1 1 4 2 6 6 2 1Resistance to acid 4 1 5 1 2 3 2 2 1Resistance to alkalis 3 1 5 2 2 3 2 2 1Resistance to hot water 3 2 5 2 3 3 1 3 1Max. temperature (°C) 130 220 200 150 120 90 140 130 260Min. temperature (°C) -40 -25 -80 -40 -30 -50 -40 -40 -190

TOLERANCE OF O-RINGS (table 4)

diameter d1 tolerance (±) diameter d1 tolerance (±)Up to 3 0,14 Up to 1,8 0,08

3 – 6 0,15 1,8 – 2,6 0,096 – 10 0,17 2,6 – 3,5 0,1

10 – 18 0,2 3,5 – 5,3 0,1318 – 30 0,3 5,3 – 7 0,1530 – 50 0,4 7 – 8 0,1750 – 80 0,65 8 – 10 0,13

80 – 100 0,85 10 – 15 0,25100 – 120 1120 – 150 1,2150 – 180 1,4180 – 250 1,8250 – 300 2,1300 – 350 2,5350 – 400 2,8400 – 500 3,4500 – 650 4,3650 – 800 6,5

O-ring ordering example


76O-RINGS O-RINGS


O-rings standards

Function and use

O-rings are sealing elements which, upon being subjected to pressure, function in both radial and axial directions. After pressure is applied to a system, the O-ring generates sealing power. As the operating pressure increases, so does the overall sealing pressure. In comparision to other sealing elements,O-rings have a number of advantages:

- easy installation- availability on stock - cost effective- wide range of use in both static and dynamic applications.

O-rings can be used in a number of industrial applications. Due to a wide range of compounds with different properties, O-rings can be employed to seal virtually all fluids and gases.

Fig. 2

Sealing joint

When subjected to pressure, the O-ring is pressed into the opposite side of the groove. To prevent the O-ring from being pressed into the sealing joint, which would result in the ring being damaged, it is advisable to choose O-rings with the largest cross-section possible for a particular application.

Under identical operating conditions and equal sealing joint width, an O-ring with a smaller cross-section is pressed into the (identical) sealing joint relatively more than an O-ring with a larger cross-section. To prevent the O-ring from being pressed into the sealing joint, a harder O-ring may be chosen or the O-ring can be combined with a back-up ring (upon inquiry, we can recommend the right size).

Material hardness

The suitable material hardness of O-rings depends on the width of the sealing joint and sealed pressure. The fol-lowing diagrams (figure 4) show the dependence:

The most important factors for determining the right O-ring hardness are the value of operating pressure and the width of sealing joint. For high pressures and wide sealing joints, it is advisable to choose harder materials to prevent the O-ring from being pressed into the sealing joint. If structurally possible, using a O-ring with medium hardness together with a back-up ring is a technically better solution as the compressive deformation is lower at 70 Sh than at 90 Sh.

type material dimensions

P.S.: Upon enquiry, we can recommend suitable materials and dimensions.

O-ring ordering example

seal

join

t wid

th (m

m)

seal

join

t wid

th (m

m)

O-RINGS STANDARDS (Table 5)

StandardRecommended dimensions of O-rings (mm)

Inner diameter d1 Thickness d2

DIN 3770

2 – 3,75 1,604 – 10 2,00

10,6 – 30 2,5018 – 50 3,1530 – 80 4,00

50 – 118 5,0080 – 315 6,30

118 – 500 8,00190 – 800 10,00

ISO 3601

1,8 – 17 1,8014 – 38,7 2,6518 – 200 3,5540 – 400 5,30

109 – 670 7,00

US Standard(AS 568A)

(MS 295 13)

1,78 – 133,07 1,781,24 – 247,32 2,624,34 – 456,06 3,53

10,46 – 658,88 5,33113,67 – 658,88 6,99

Swedish Standard (SMS 1588)

3,1 – 37,1 1,603,3 – 17,3 2,40

19,2 – 144,3 3,0044,2 – 499,3 5,70

144,1 – 249,1 8,40

French Standard

2,4 – 8,9 1,908,9 – 18,4 2,70

18,4 – 37,3 3,6037,43 – 113,67 5,33

113,67 – 393,07 6,99

Fig. 3

F

= =

com

pres

sion


98O-RINGS O-RINGS


Installation instructions

Given the functionality and quality of O-rings, they are most suitable for static application. For dynamic applications, there are certain restrictions which must be observed. It is important to comply with pressure and temperature limits, medium type, surface roughness, size of sealing joint and other parameters.

The following graphs show values for compression of O-rings for various applications. If these values are observed, sufficient contact surface necessary for good sealing peformance is ensured. In dynamic applications, these values must be lower due to higher friction.

defo

rmat

ion

(%)

2. DETERMINING THE RIGHT O-RING SIZE

It is always advisable to choose O-rings with the largest thickness (d2) possible as they have several advantages compared to O-rings with lower d2 values:

- lower abrasion which means higher service life- lower deformation- larger contact surface

To determine the dimensions of the groove and the inner diameter of the O-ring, proceed as follows:

- choose the highest possible thickness (d2) for your construction - dimensions of L1 and S grooves can be found in the tables for installing dimensions - the basic groove dimension is given for the main ring types: a) sealing on the outside da = Da - 2 x S b) sealing on the inside Db= db + 2 x S

- the inner dimension (d1) is determined according to the moulds list for the main ring types: - sealing on the outside: - the inner O-ring diameter should be identical or only slightly smaller than the

da groove diameter d1 = da < max. 6 % - it is recommended to lightly position the ring on the groove diameter

- sealing on the inside: - the inner O-ring diameter should be identical or only slightly smaller or larger than

the db piston rod diameter > max. 3 % d1 = db < max. 6 % - this ensures that the O-ring has the desired larger dimension on the outer diameter

Fig. 6

thickness d2 (mm)


1110O-RINGS O-RINGS


Detailed groove construction

The grooves in which the O-rings are positioned should have a rectangular recess. Maximum allowed wall bevel is 5%. It is important that the pressure of the medium can spread along the whole S profile. To this end, is it necessary to determine the adequate size of the groove width L1 and the sealing joint on the pressure side. Because the O-ring material has higher heat expansion than metals, and to account for any swelling, the inner volume of the groove should be about 25% larger than the O-ring volume. To ensure that the O-ring does not get jammed or cut during assembly, it is necessary to take care that the bevel values (see fig. 6) are not lower than those stated in the following table (table 6).

3. STATIC SEALING - RADIAL DIMENSION - RECTANGULAR GROOVE

O-rings may be used as a static sealing element with radial compression, for example for sealing of valves, fittings, hydrualic or pneumatic cylinders. They can be employed for sealing both on the inside and on the outside. If, for reasons of design, the sealing joint equals “zero”, it is possible to seal pressures of 500 bar and higher. At high or pulsating pressure, or for larger dimensions of sealing joints which are results of the nature of the technical construction, it is recommended to use retainer rings.

Fig. 7

Fig. 8

If retainer rings are used, the groove width value must be larger corresponding to the added width of the retainer ring.

Bevel and radius - see table 6 and 7.

For pulsating pressure, this value must be taken from table 18 (dynamic sealing).

MINIMUM BEVEL in mm (table 6)

Thickness d2 min. bevel z Thickness d2 min. bevel z1,0 1,0 4,0 2,01,5 1,0 4,5 2,31,6 1,0 5,0 2,51,8 1,1 5,3 2,7

1,78 1,1 5,33 2,71,9 1,2 5,7 3,02,0 1,2 6,7 3,12,4 1,4 7,0 3,62,5 1,4 6,99 3,6

2,65 1,5 8,0 4,02,62 1,5 8,4 4,23,0 1,6 9,0 4,33,5 1,8 10 4,5

3,55 1,8 12 5,03,53 1,8 15 7,0

FILLET in mm (table 7)

Thickness d2 1,0 to 2,5 2,5 to 10

radius r1 0,1 0,25

radius r2 0,2 0,6

INSTALLING DIMENSIONS - STATIC SEALING (table 8)

Thickness d2 Depth S Width L1 Thickness d2 Depth S Width L11,0 0,8 1,3 4,0 3,15 5,21,5 1,15 1,9 4,5 3,6 5,81,6 1,2 2,1 5,0 4,0 6,51,8 1,35 2,3 5,3 4,3 6,9

1,78 1,35 2,3 5,33 4,3 6,91,9 1,45 2,4 5,7 4,65 7,42,0 1,5 2,6 6,0 4,96 7,82,4 1,8 3,1 7,0 5,85 9,12,5 1,9 3,2 6,99 5,85 9,1

2,65 2,0 3,4 8,0 6,75 10,42,62 2,0 3,4 8,4 7,15 10,93,0 2,3 3,9 9,0 7,7 11,73,5 2,7 4,5 10 8,65 13,0

3,55 2,75 4,5 12 10,6 15,63,53 2,75 4,5 15 13,5 19,5

TOLERANCE AND MATING in mm (table 9)

Dimensions Tolerance

Da, db H 8/f 7

da h 11

Db H 11

up to 4 up to 6 up to 8 up to 10

+0,2/0 +0,3/0 +0,4/0 +0,5/0

RECOMMENDED ROUGHNESS R MAX. IN μm (table 10)Area Roughness Ra

Basic groove radius da, Db 1,6

Groove side 3,2

Sealing surface da, Db 1,6

MAXIMUM SEALING JOINT F in mm - STATIC SEALING (table 11)

Hardness (Sh A) Pressure (bar) Maximum sealing joint F

without retainer ring with retainer ring

7025 0,25

0,350 0,2100 0,15

80

50 0,25

0,3100 0,2150 0,15200 0,1

90

100 0,25

0,3150 0,2200 0,15250 0,1


1312O-RINGS O-RINGS


4. STATIC SEALING - AXIAL DIMENSION

Static sealing - axial installing dimensions - rectangular groove

O-rings are used as static sealing elements with axial deformation, for example for sealing of shafts or covers. At high pressures, it is important to make sure that the screws are sufficiently prestressed and that the metal parts are fitted tightly enough. This ensures that the sealing surfaces cannot disconnect under pressure and prevents occurance of gaps. If optimal construction is presumed, pressures of 1000 bar and higher can be sealed. If the pressure comes from the outside, it is necessary to choose O-rings with slightly smaller (about 1 - 2%) d1 inner diameter than the inner groove diameter d3. If the pressure comes from the inside, it is necessary to chose O-rings with slightly larger (about 1 - 2%) outer diameter than the groove diameter D3.

Installing dimensions see table 8

Static sealing - axial installing dimensions - trapezoidal groove

Trapezoidal grooves for O-rings are useful if the function of the sealed joint requires that it is regularly opened while the O-ring stays firmly attached in the groove. The dimensions of the O-rings have to be chosen according to the following formula for inner diameter of the O-ring: d1 = dm - 2 x d2

Static sealing - axial-radial installing dimensions - triangular groove

These installing dimensions are generally not recommended as they do not allow sufficient space for possible changes in the O-ring volume. Rectangular grooves are a more suitable alternative. Sometimes, triangular grooves are used to seal shafts or covers. For such aplications of O-rings in triangular grooves, the following table states the O-ring thickness (d2) values in relation to the bevel value b.

TOLERANCE in mm (table 12)

Thickness d2 up to 4 up to 6 up to 8 up to 10

Groove depth S +0,05/0 +0,07/0 +0,09/0 +0,1/0

Groove width L1 +0,2/0 +0,3/0 +0,4/0 +0,5/0

Diameter d3 h 11

Diameter D3 H 11

Radii table 7

Roughness table 10

INSTALLING DIMENSIONS - TRAPEZOIDAL GROOVE in mm (table 13)

Thickness d2 3,5 5 5,33 5,7 6,99 8 8,4 9 10

Groove depth ST 2,8 4,15 4,4 4,8 5,95 6,85 7,25 7,8 8,7

Groove width LT 3,05 4,1 4,35 4,75 5,65 6,5 6,8 7,25 7,95

Radius rT 0,25 0,25 0,25 0,4 0,4 0,5 0,5 0,5 0,5

Radius RT 0,8 1,5

Inner diameter d1 see text

Angle α 24°

TOLERANCE in mm - TRAPEZOIDAL GROOVE (table 14)

Groove depth ST (±) 0,05

Groove width LT (±) 0,05

Roughness grades Table 10

INSTALLING DIMENSIONS - TRIANGULAR GROOVE in mm (table 15)

Thickness d2 Bevel width b Radius R1 1,02 1,4

1,2 1,25 1,6 +0,1 0,21,5 1,52 21,6 2,11,8 1,78 2,4 +0,1 0,31,9 2,62 2,7

2,4 3,2 +0,1 0,42,5 3,42,6 2,26 3,5

2,65 2,7 3,6 +0,15 0,63 4,1

3,15 4,33,5 3,53 4,7 +0,15 0,9

3,55 3,6 4,84 5,4

4,5 6,1 +0,15 1,25 6,8

5,3 5,33 7,25,7 7,7 +0,2 1,56 8,1

6,3 8,57 6,99 9,5 s+0,2 28 10,8

8,4 11,410 13,5 +0,25 2,512 16,214 1916 21,6 +0,25 320 27


1514O-RINGS O-RINGS


5. DYNAMIC SEALING

O-rings are not an entirely suitable sealing element for dynamic applications as the sliding movement at growing pressure makes necessary lubrication more difficult. This quickly leads to increased abrasion. Most of all, the service life depends on the following factors: presence of lubricating layer, pressure values, temperature, size of sealing joint, speed of sliding movement, medium type as well as the quality of surface areas of metal parts. Limits of 100 bar and 0,3 m/s should not be exceeded. If the sealing joint is rather larger in size, back-up rings should always be used on both sides of the O-ring. In most cases, more suitable sealing elements can be found for dynamic sealing.

If back-up rings are used, the groove width value must be larger corresponding to the added width of the back-up ring. L1 dimension tolerance - see table 17.

Hydraulic devicesWhen dynamic sealing is used for hydraulic devices, the lubricant type is one of the most important factors with regard to service life. Lubricating effect of mineral oils is substantially better compared to water or water - oil emulsions. The second crucial factor influencing the service life is the number and height of strokes. Given this, O-rings are more suitable for spindle of valve than for cylinders with high strokes and quick speed.

Pneumatic devicesFor pneumatic devices, the same principles as for hydraulic devices apply. Although the pressures in pneumatic devices are lower, sufficient lubrication is harder to achieve than in hydraulic devices. To achieve lower friction on acceleration, is is possible to install the O-ring as a floating ring when used for pneumatic devices. The groove depth S and width L1 must be larger than the thickness (d2).

Rotational movementsO-rings are generally not suitable for rotational movements as it is not possible to ensure sufficient lubricant supply to sealing surfaces. This leads to increased friction, local overheating and quick wear. In exceptional cases where no other sealing element can be used, it is recommended to install the O-ring on the solid part to avoid the impact of centrifugal forces. For most rotary applications, there are more suitable other sealing elements.

Installation bevels and diameters - see tables 6 and 7.

INSTALLING DIMENSIONS - DYNAMIC SEALING (table 16)

Thickness d2 Width L1 Depth - hydr. SDepth -

pneum. S Thickness d2 Width L1 Depth - hydr. S

Depth - pneum. S

1,0 1,3 0,9 0,95 3,53 4,2 3,1 3,251,5 1,9 1,3 1,35 4,0 4,8 3,5 3,71,6 2,0 1,4 1,45 4,5 5,4 4,0 4,21,8 2,3 1,5 1,55 5,0 6,0 4,45 4,65

1,78 2,3 1,5 1,55 5,3 6,4 4,7 4,951,9 2,4 1,7 1,7 5,33 6,4 4,7 4,952,0 2,4 1,7 1,8 5,7 6,9 5,1 5,352,4 2,9 2,1 2,15 6 7,2 5,4 5,652,5 30 2,2 2,25 7,0 8,4 6,3 6,6

2,65 3,1 2,3 2,35 6,99 8,4 6,3 6,62,62 3,1 2,3 2,35 8,0 9,6 7,2 7,53,0 3,6 2,6 2,75 8,4 10,1 7,6 7,93,5 4,2 3,1 3,25 9,0 10,8 8,2 8,5

3,55 4,2 3,1 3,25 10 12,0 9,1 9,5

TOLERANCE AND ENGINEERING FIT in mm (table 17)

Dimensions Tolerance

Da, db H 8/f 7

da h 9

Db H 9

Ring diameter d2 up to 4 up to 6 up to 8 up to 10

Groove width L1 +0,2/0 +0,3/0 +0,4/0 +0,5/0

RECOMMENDED ROUGHNESS R MAX. in μm (table 18)

Area Roughness RaBasic groove radius da, Db 1,6

Groove side L1 3,2

Sliding surfaces Da, db max. 0,4

MAXIMUM SEALING JOINT F in mm - DYNAMIC SEALING (table 19)

Hardness (Sh A) Pressure (bar) Maximum sealing joint F

without back-up ring with back-up ring

7010 0,25

0,325 0,250 0,1

8025 0,25

0,350 0,275 0,1

9050 0,2

0,375 0,15100 0,1


1716O-RINGS O-RINGS


PTFE O-rings

PTFE O-rings can be used in the temperature range from -200°C to +260°C. Moreover, they are resistant to most of all chemical substances. Due to limited elasticity which also means greater prestressing force, PTFE O-rings should be only used for static sealing in axial groove constructions. However, they can also be placed in grooves which were originally designed for elastomeric O-rings. In such cases, it is necessary to take care that the PTFE O-ring is not stretched or packed too tightly during installation. For special cases which require the chemical properties of PTFE combined with the elastic properties of elastomeric substances, we can deliver PTFE enveloped O-rings made of Viton or silicone.

Groove dimensions for O-rings used for vacuum sealing

Take care that the O-ring fills the groove as tightly as possible so that no leakage occurs as a result of shrinkage of the elastomeric substance in the vacuum. Moreover, it is necessary to prevent the O-ring from moving in the groove. The processing of sealing surfaces should be carried out with the greatest possible care. For vacuum sealing, gas permeability of the O-ring material is a significant factor. This material characteristic depends on the nature of material and varies with temperature. Butyl and Viton are suitable materials for this sealing type; kalrez can also be used under certain circumstances.

Packings with circular diameter (cords)

Sets for service

- assembly boxes for use in dynamic applications (contains O-ring type series depending on the box type) - please inquire for a list of type series

- assembly boxes for bonding of O-rings in static applications(contains 12 dimension of cords, adhesive, measure, other equipment)

GROOVE DIMENSIONS FOR PTFE O-RINGS (table 20)

L1 = d2 + 10%

S = d2 - 10% up to 20% for d2 < 5,0

S = d2 - 10% up to 15% for d2 > 5,0

R = (d2 + 10%) / 2

GROOVE DIMENSIONS FOR VACUUM SEALING (table 21)

Thickness d21,8 2,65 3,55 5,3 7,0

1,78 2,62 3,53 5,33 6,99Depth S 1,27 – 1,32 1,88 – 1,98 2,57 – 2,62 3,86 – 3,94 5,11 – 5,18

Width L1 2,1 – 2,24 3,0 – 3,12 3,99 – 4,14 5,99 – 6,12 7,75 – 7,87

Radius r1, r2 Table 7

DIMENSIONS RANGE (table 23)

NBR 70 Sh FPM 70 Shdiameter d2 tolerance ± diameter d2 diameter d2

1,55 0,2 2 0,21,78 0,2 2,4 0,2

2 0,2 2,5 0,22,4 0,25 2,62 0,252,5 0,25 3 0,25

2,62 0,25 3,5 0,33 0,25 5,53 0,3

3,2 0,35 4 0,33,5 0,35 4,5 0,3

3,53 0,35 4,75 0,34 0,35 5 0,3

4,5 0,4 5,33 0,35 0,4 5,5 0,3

5,33 0,4 5,7 0,35,5 0,4 6 0,35,7 0,4 6,35 0,46 0,4 6,5 0,4

6,35 0,55 6,99 0,46,5 0,55 7 0,4

6,99 0,55 7,5 0,47 0,55 8 0,4

7,5 0,55 8,4 0,48 0,55 8,5 0,4

8,4 0,55 9 0,48,5 0,55 10 0,49 0,55 11 0,5

10 0,55 12 0,511 0,65 13 0,512 0,65 14 0,513 0,65 15 0,514 0,65 16 0,515 0,65 18 116 0,65 20 118 0,85 22 120 0,85 25 122 0,85 30 1,325 130 1

Upon inquiry, we can also deliver sealing cords made of NBR 80 Sh and 90 Sh, FPM 80 Sh and 90 Sh or Si.


1918O-RINGS O-RINGS

Dimension series - material NBR Dimension series - material NBR


2120O-RINGS O-RINGS



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51O-RINGS O-RINGS

Dimension series - material FPMDimension series - material FPM

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50O-RINGS O-RINGS

Dimension series - material NBR Dimension series - material FPM


5352O-RINGS O-RINGS

Dimension series - material FPM Dimension series - material FPM


5554O-RINGS O-RINGS



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8382O-RINGS O-RINGS


X-rings were primarily developed to limit the twisting of rings in the groove. The base is the square-shaped cross-section with ring grooves. The width and thickness of these rings correspond with the dimensions of the classical O-rings. Therefore, both types are exchangeable. The ring has a small touch surface for pressure up to 40 bars as well as less friction than the O-ring. The X-ring cannot roll away and therefore it will also not twist. An advantage of the X-ring over the O-ring is only the fact that it is more advantageous for radial movement if it is not possible to use shaft seals. The life cycle is dependent upon the quality of the surface of the friction surfaces.

Cross-section Initial Radial Pressure Groove dimensionsRadius Maximum radius joint

WDynamic

applicationmax.min.

Staticapplication

max.min.

Depth of Groove Width of Groove

Dynamic t1 +0,05

Static t/h +0,05 b1, b4 +0,2 b2 +0,2 b3 +0,2 r1 S

1,020,300 0,350

0,80 0,75 1,20 - - 0,10 0,030,115 0,165

1,270,330 0,430

1,00 0,90 1,40 - - 0,10 0,030,145 0,245

1,520,350 0,450

1,25 1,15 1,70 - - 0,22 0,040,165 0,265

1,780,360 0,460

1,50 1,40 2,00 3,40 4,80 0,22 0,050,175 0,275

2,620,400 0,450

2,30 2,25 3,00 4,40 5,8 0,30 0,080,215 0,265

3,530,430 0,530

3,20 3,10 4,00 5,40 6,80 0,40 0,080,205 0,305

5,330,560 0,710

4,90 4,75 6,00 7,70 9,40 0,40 0,100,250 0,400

7,000,700 0,950

6,40 6,20 8,00 10,50 13,00 0,60 0,100,350 0,600

TECHNICAL PARAMETERS

Pressure 400 bars (500 bars in combination with the supporting ring)

Speed 0.5 m/s

Temperature -50 up to +200 °C

Standard Thickness of X-Rings

1,78 2,62 3,53 5,33 7,00

If you have any special requirements for X-rings, please contact our technical department. We will make recommendations based on your needs:

- Material of sliding surfaces - Surface treatments- Ways of greasing- Shapes of grooves- Tolerance of grooves- The suitable dimension with the recommended tolerance- The complete technical and design documentation

Documents

Technical information Technical informationContent · 6 7 O-RINGS O-RINGS Technical information Technical information O-rings standards Function and use O-rings are sealing elements