description
O-Ring activated, asymmetrical PTFE rod seal, low friction, good dry running proper- ties and adaptation possibilities for diverse temperatures and media by selection of suitable O-Ring material, almost no dead spots as required for applications in food & pharma industry.
- asymmetric single-acting rod lip seals, with the dynamic sealing lip being shorter than the static one. an O-ring inserted in the groove creates the preload.
- interference fit on the outside diameter.
- various materials are available for different purposes.
- good sealing effect across a wide temperature range.
- sealing effect enhanced by high recovery rate.
- for pressures up to 200 bar as a seal between pressurised space and atmosphere
(in certain cases even above, see “gap dimensions”).
- good sealing in all pressure ranges.
- excellent static and dynamic sealing after short run-in time.
- suitable for short and long travel.
- small break-awayload.
- no reverse leakage (i.e. minor relative motion of the sealing edges when the direction is changed).
- little friction when dry running or when used in media with poor lubrication
(conditionally suitable for use in aqueous media).
application
not bolded symbols; please consult our technical for application limitations
category of profile
machined only.
single acting
the RS03-F seal is designed for use as a rod seal.
application range
- reciprocating and swiveling rods on cylinders,push rods, fittings in the chemical industry.
note
- considering the limited long-time rupture strength of the PTFE materials, the ratio of cs/H should not fall below a value of 1/1.5. using back up rings can widen the application range.
- cross-sections limited with 15 mm.
- varying the angle of the chamfer on the dynamic sealing lip allows adaptation to media (steeper angle for high viscosity media)
- respectively a pressure relief (flat angle).
function
RS03-F profiles are lip seals designed to seal pressurised space against the atmosphere; mainly for reciprocating movements. the design is based on application in aggressive media or with high thermal demands. the operating parameters are as defined in the sealing data sheet and material data. requirements deviating from these parameters can be met to a certain degree by changing the geometry in the software program.
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).
note on special materials:
other materials such as Viton, Silicone, EPDM, H-NBR, etc., can be used for the preload element, but they are only useful in specific cases (temperature or
chemical influences).
gap dimension
the decisive factor for the function of the seal is the largest gap dimension occurring during operation on the non-pressurised side of the seal.
| operating pressure | cs = (ØD – Ød)/2 mm | |||
| 4 | 5 | 7.5 | 10 ≤ | |
| safe extrusion gap (mm) | ||||
| 50 bar (5 MPa) | 0.30 | 0.30 | 0.55 | 0.65 |
| 100 bar (10 MPa) | 0.25 | 0.25 | 0.40 | 0.50 |
| 150 bar (15 MPa) | 0.20 | 0.22 | 0.35 | 0.45 |
| 200 bar (20 MPa) | 0.15 | 0.20 | 0.30 | 0.40 |
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 table refers to a operating temperature of 80°C. temperatures below may increase the safe extrusion gap slightly, at temperatures above 80 °C, the gap dimensions has to be reduced or a stronger profile selected.
in exceptional cases, a pressure above the limit of 200 bar is possible, the safe extrusion gap is the result of the tolerance pair H8/f8, influences due to thermal expansion have to be considered. we also recommend contacting our our technical department.
surface quality
| surface roughness |
Rtmax (μm) |
Ra (μm) |
| sliding surface | ≤2.0 | ≤0,05-0,3 |
| bottom of groove | ≤10 | ≤1,6 |
| groove face | ≤10 | ≤1,6 |
tolerance recommendation
| seal housing | tolerances |
| Ød | h10 |
| ØD | H9 |
mode of installation
| Ød | type of installation |
| ≤ 30•cs | open mounting space required |
| > 30•cs | snap mounting possible |
normally, an open mounting space is to be provided. the profile snaps into simple grooves, if the diameter/cross-section ratio is big enough. a special groove design is, however, required (please contact our technical department).
recommended mounting space:
recommended guide tolerance D1:
| d f8 [mm] |
p ≤ 100 [bar] |
100 < p ≤ 200 [bar] |
p > 200 [bar] |
secondary seal |
| ≤ 100 | H10 | H8 | H8 | H8 |
| > 100 ≤ 200 | H10 | H8 | H7 | H8 |
| >200 | H9 | H8 | H7 | H8 |
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 | |
| (2) | 2 | 1 |
| (3) | 3 | 1.5 |
| 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…
with PTFE materials, the profile size does not depend so much on the seal diameter but rather on pressure and extrusion gap. this relationship is described under “gap dimensions”. nominal widths not shown in the diagram can be interpolated.
the ratio between nominal width and seal height cs/H should not drop below 1/1.5. therefore we recommend the following housing heights.
| Ød [mm] | ØD [mm] | L [mm] | cs = (ØD – Ød)/2 [mm] |
| 5 ~ 24,9 | ød + 8 | 6.3 | 4 |
| 25 ~ 49,9 | ød + 10 | 8 | 5 |
| 50 ~ 149,9 | ød + 15 | 10 | 7.5 |
| 150 ~ 299,9 | ød + 20 | 14 | 10 |
| 300 ~ 499,9 | ød + 25 | 17 | 12.5 |
| 500 ~ 699,9 | ød + 30 | 25 | 15 |
| 700 ~ 1000 | ød + 40 | 32 | 20 |
| > 1000 | ød + 40 | 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.