description
chevron sealing set, machined surface design. in back-to-back arrangement with one intermediate chevron for double sided pressure activation, in single acting applica- tions with more intermediate chevrons possible. for heavy industry hydraulics.
- symmetric single-acting piston sealing set consisting mainly of one chevrons, combined with pressure ring and support ring to form a set.
- various materials are available for different purposes.
- good sealing in all pressure ranges,particularly in the low pressure range.
- for pressures up to 500 bar as a seal between pressurised spaces.
- excellent static and dynamic sealing.
- suitable for short and long travel.
- very sturdy and wear-resistant.
- insensitive to thermal damage caused by air in the oil.
- open mounting space required (see mode of installation).
- by combining various materials,the packing can be adjusted to the operating conditions.
- by varying the number of packings,friction as well as leakage behaviour can be influenced.
- the pressure and the support ring can be split for easier installation, the chevron snaps in the groove uncut (see mode of installation).
- mainly used for repair purposes.use more modern systems for new designs.
application
not bolded symbols; please consult our technical for application limitations
category of profile
machined only.
single acting
the PS 1012 seal is designed for use as a piston seal – either single or double acting where two seals are used ‘back to back’
area of application: hydraulics
- reciprocating pistons in hydraulic cylinders; small swivelling motion also permissible.
- especially for heavy hydraulic applications or heavy-dutyoperating conditions.
- for repairs of heavy machinery and for normal wear,when re-tightening is possible
note
- expensive and complex design.
- high degree of friction and thus little mechanical efficiency.
- for small amounts.for large numbers, the K1012-M profile is preferred.
- too many chevrons or too high clamping torque at installation can load to increased friction, and wear (for standard applications use
maximum 1 chevrons).
function
PS 1012 profiles are single-acting chevron seal sets designed to seal pressurised space against the atmosphere or – in case of back to back arrangement with intermediate guidering – to seal between two pressurised spaces, 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
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 ma-
terials are to be preferred, polyurethane materials increase wear resistance. for higher gliding speeds another sealing system should be used (e.g. PTFE
materials).
gap dimension:
when using a pressure ring, the extrusion gap is already integrated in the seal. the gap between piston and housing should not exceed cs·0.05.
surface quality
| surface roughness |
Rtmax (μm) |
Ra (μm) |
| sliding surface | ≤2,5 | ≤0,05-0,3 |
| bottom of groove | ≤6,3 | ≤1,6 |
| groove face | ≤15 | ≤3 |
tolerance recommendation
| seal housing | tolerances |
| Ød | h9 |
| ØD | H9 |
mode of installation
open housings are required.
in case of already existing closed grooves the pressure and the support ring can be split for installation (pressure ring with cutting gap 0). the
chevron has to be slipped in uncut. the support ring should be made of two parts (like ST08+K10) for easier installation into closed grooves.
recommended mounting space:
plastic guiderings (wearbands) have to feature a adequate cutting gap (recommendation: 2-5% of D). if metalic guides are used, spiral grooves shall be provided. in order to avoid drag pressure built up in case of back-to-back arrangement, the distance between the seals should be as small as possible.
insertion chamfer:
in order to avoid damage to the piston seal during installation, the piston and the housing 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 |
instead of a chamfer, the piston can also be designed with a radius. recommended size of the radius is equal to size of chamfer (R=c).
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 width and seal height should be in accordance with following recommendations (see also manufacturing notes)
| ØD [mm] | Ød [mm] | L [mm] | cs = (ØD – Ød)/2 [mm] |
| 5 ~ 24,9 | ØD – 8 | 6 | 4 |
| 25 ~ 49,9 | ØD – 10 | 7 | 5 |
| 50 ~ 74,9 | ØD – 12 | 8 | 6 |
| 75 ~ 149,9 | ØD – 16 | 10 | 7.5 |
| 150 ~ 299,9 | ØD – 20 | 12 | 10 |
| 300 ~ 500 | ØD – 24 | 18 | 12.5 |
| 500 ~ 750 | ØD – 30 | 20 | 15 |
| > 750 | ØD – 40 | 26 | 20 |
manufacturing notes
the following nominal widths are preferred. the theoretical packing height SH11 should be designed in accordance with the recommended values:
| CS | SH11 |
| 4 | 2.2 |
| 5 | 2.5 |
| 6 | 3 |
| 7.5 | 3.5 |
| 10 | 5 |
| 12.5 | 6 |
| 15 | 7.5 |
| 20 | 10 |
| 25 | 12.5 |
| 30 | 15 |
in order to be able to maintain the required height irrespective of the accumulated packing height ‘h’, the pressure ring is individually adjusted during the production of the V-packing set. to do so, a control dimension is provided by the machine software with a view to assisting this process.
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.