description
symmetric rod seal with support ring for simple applications to serve repair purpose, not recommended for new designs (profile RS01 preferred). retainer ring in angled design possible.
- symmetric single-acting rod seal.
- no interference fit on the outside diameter.
- various materials are available for different purposes.
- sealing effect across a wide temperature range.
- sealing effect enhanced by high recovery.
- for pressures up to 400 bar as a seal between pressurised space and atmosphere.
- good sealing in the low pressure range.
- excellent static and dynamic sealing.
- suitable for long travel.
- little inclination to“stick-slip”.
- small break-awayload after prolonged periods of standstill.
- the stabilisation of the sealing element in the housing is achieved by a retainerring.
- this retainer ring can be designed straight or as a angled ring (for easier center-ing and installation). the straight design has to be furnished with pressure reliefgrooves, the angled design needs balancing holes (for details see “fabricationtolerances for machined seals”, ES 222.222).
application
not bolded symbols; please consult our technical for application limitations
category of profile
machined only.
single acting
the RS 22 seal is designed for use as a rod seal.
area of application: hydraulics
- reciprocating rods on hydraulic cylinders,push rods, fittings and plungers.
- as rod seals for applications with small extrusion gap and without specific impact load.
- can also be used as a pivot seal in the case of small loads.
- repair seal for older equipment.
- replacement for rubber fabric seals of older equipment.
note
- under certain operating conditions, this seal may “pump” via the trailing side, i.e. as it does not fit tightly on the outside diameter, small amounts of operating media may be pressed out when the seal is deformed under pressure which may appear to be leakage.
- open housings required.
function
RS 22 profiles are lip seals designed to seal pressurised space against the atmosphere; mainly for reciprocating movements. the design is based on application in standard hydraulic systems with conventional hydraulic oils. the operating parameters are as defined in the seal- ing data sheet and material data. requirements deviating from these parameters can be met to a certain degree by changing the geom- etry in the software program.
operating parameters & material
| material | back-up ring | temperature | max. surface speed | max. pressure 1 | hydrolysis | dry running | wear resistance |
| PU | POM / PA2 | -30 °C … +110 °C | 0,5 m/s | 400 bar (40 MPa) | – | + | + |
| HPU | POM / PA2 | -20 °C … +110 °C | 0,5 m/s | 400 bar (40 MPa) | + | + | + |
| LTPU | POM / PA2 | -50 °C … +110 °C | 0,5 m/s | 400 bar (40 MPa) | – | + | + |
| SPU | POM / PA2 | -20 °C … +110 °C | 0,7 m/s | 400 bar (40 MPa) | + | + | + |
| GPU | POM / PA2 | -30 °C … +100 °C | 0,5 m/s | 400 bar (40 MPa) | + | + | + |
the stated operation conditions represent general indications. it is recommended not to use all maximum values simultaneously. surface speed limits apply only to the presence of adequate lubrication film.
1 pressure ratings are dependent on the size of the extrusion gap.
2 POM up to ø260 mm, PA above ø260 mm
++ … particularly suitable o … conditional suitable
+ … suitable – … not suitable
for detailed information regarding chemical resistance please refer to our „list of resistance“. for increased chemical and thermal resistance rubber
materials are to be preferred, attention should be paid to restrictions for pressure range and wear resistance. for higher gliding speeds another system should be used (e.g. PTFE materials).
gap dimension
| operating pressure | cs = (ØD – Ød)/2 mm | |||||
| 4 | 5 | 7.5 | 10 | 12.5 | 15 | |
| safe extrusion gap (mm) | ||||||
| 100 bar (10 MPa) | 0.18 | 0.22 | 0.32 | 0.38 | 0.45 | 0.53 |
| 200 bar (20 MPa) | 0.12 | 0.16 | 0.25 | 0.33 | 0.40 | 0.45 |
| 0.07 | 0.13 | 0.21 | 0.28 | 0.36 | 0.42 | 0.25 |
| 400 bar (40 MPa) | 0.05 | 0.10 | 0.19 | 0.26 | 0.33 | 0.39 |
important note:
the above data are maximum value and can’t be used at the same time. e.g. the maximum operating speed depend on material type, pressure, tem- perature and gap value. temperature range also dependent on medium.
the diagram applies to an operating temperature of 70 °C.
use larger cross sections to increase maximum allowed gap dimension.
surface quality
| surface roughness |
Rtmax (μm) |
Ra (μm) |
| sliding surface | ≤2,5 | ≤0,1-0,5 |
| bottom of groove | ≤6,3 | ≤1,6 |
| groove face | ≤15 | ≤3 |
tolerance recommendation
| seal housing | tolerances |
| Ød | f8 |
| ØD | H10 |
mode of installation
open housings are required.
recommended mounting space:
recommended guide tolerance D1:
| d f8 [mm] |
p ≤ 100 [bar] |
100 < p ≤ 200 [bar] |
p > 200 [bar] |
| ≤ 100 | H10 | H8 | H8 |
| > 100 ≤ 200 | H10 | H8 | H7 |
| >200 | H9 | H8 | H7 |
insertion chamfer:
in order to avoid damage to the rod seal during installation, the piston rod is to be chamfered and rounded as shown in the “recommended mounting space” drawing. the size of chamfer depends on the seal type and profile width.
| cs (mm) | c (mm) | |
| α = 15⁰ … 20⁰ | α = 20⁰ … 30⁰ | |
| 4 | 3.5 | 2 |
| 5 | 4 | 2.5 |
| 6 | 4.5 | 3 |
| 7.5 | 5 | 4 |
| 10 | 6 | 5 |
| 12.5 | 8.5 | 6.5 |
| 15 | 10 | 7.5 |
| 20 | 13 | 10 |
seal & housing recommendations
please note that we are able to produce those profiles to your specific need or any non standard housing. for detail measurements, please see Jet seal pars catalog…
the ratio between nominal with and seal height cs/H should not drop below 1/1.25. therefore we recommed the following housing heights.
| cs = (ØD – Ød)/2 [mm] | L [mm] |
| 8 | 4 |
| 9 | 5 |
| 11 | 6 |
| 14 | 7.5 |
| 17 | 10 |
| 20 | 12.5 |
| 25 | 15 |
| 32 | 20 |
fitted:
don’t hesitate to contact our technical department for further information or for special requirements (temperature, speed etc.), so that suitable materi- als and/or designs can be recommended.