Piston Seals · PDD
Operating Conditions
| Pressure | Up to 35 MPa |
| Speed | Up to 15 m/s |
| Temperature | -45 °C to +200 °C. Depending on seal and O-Ring material |
| Media | Mineral oil-based hydraulic fluids, flame retardant hydraulic fluids, environmentally friendly hydraulic fluids (bio-oils), phosphate ester, water and others, depending on temperature, seal and O-Ring material compatibility see Materials for PDD |
| Clearance | The maximum permissible radial clearance Smax is shown in Installation Dimensions, as a function of the operating pressure and functional diameter |
Important Note : The above data are maximum values and cannot be used at the same time, e.g. the maximum operating speed depends on material type, pressure, temperature and gap value. Temperature range also depends on media.
Recommended Materials
The following material combinations have proven effective for hydraulic applications:
PDD in PS8WM
All round material for light to medium hydraulic applications with linear or helical movements in mineral oils, flame retardant hydraulic fluids, phosphate ester, bio-oils or fluids having low lubricating properties:
| O-Ring | NBR 70 Shore A | N |
| FKM 70 Shore A | V | |
| EPDM 70 Shore A | E | |
| Set Code | PS8WMN, PS8WMV or PS8WME |
PDD in PS61B
For medium to heavy applications with linear movements in mineral oils and other media with good lubrication:
| O-Ring | NBR 70 Shore A | N |
| FKM 70 Shore A | V | |
| Set Code | PS61BN or PS61BV |
For specific applications, all PTFE materials are available.
Other material combinations are listed in Materials for PDD.
Materials for PDD
Installation Dimensions - Standard Recommendations
| Series No. | Bore Diameter DN H9 | Groove Diameter | Groove Width | |
| Standard Application | Available Range | d1 h9 | L1 +0.2 | |
| PDD | 5 - 13.9 | 5 - 139.9 | DN - 2.9 | 2.4 |
| PDD | 14 - 24.9 | 8 - 259.9 | DN - 4.5 | 3.6 |
| PDD | 25 - 45.9 | 12 - 469.9 | DN - 6.2 | 4.8 |
| PDD | 46 - 124.9 | 20 - 669.9 | DN - 9.4 | 7.1 |
| PDD | 125 - 669.9 | 80 - 999.9 | DN - 12.2 | 9.5 |
| Series No. | Radius | Radial Clearance Smax | O-Ring Cross Section | |||
| r1 max | 2 MPa | 10 MPa | 20 MPa | 35 MPa | d2 | |
| PDD | 0.4 | 0.10 | 0.10 | 0.08 | 0.05 | 1.78 |
| PDD | 0.4 | 0.15 | 0.15 | 0.10 | 0.07 | 2.62 |
| PDD | 0.6 | 0.25 | 0.20 | 0.15 | 0.08 | 3.53 |
| PDD | 0.8 | 0.35 | 0.25 | 0.20 | 0.10 | 5.33 |
| PDD | 0.8 | 0.50 | 0.30 | 0.25 | 0.15 | 7.00 |
Ordering Guide
PDD complete with O-Ring, standard application:
| Series | PDD |
| Bore Diameter | DN = 80.0 mm |
| TMK Part No. | PDD0800071 |
PDD 0800 071 PS8WM N
1 2 3 4 5
| 1 | TMK Series No. |
| 2 | Bore Diameter x 10 |
| 3 | Groove Width x 10 |
| 4 | Material Code ( Seal Ring ) |
| 5 | Material Code ( O-Ring ) |
