SKF SLC ROD SEALS
SKF SLC produces over 30 million seals each year in close to 50,000 part numbers. Rod and buffer seals maintain sealing contact in sliding motion between the cylinder head and the piston rod. Depending on the application, a rod sealing system can consist of a rod seal and a buffer seal or a rod seal only. Rod sealing systems for heavy duty applications typically consist of a combination of both seal types, whereas the buffer seal is arranged between the rod seal and the piston in the cylinder head. Rod seals determine the tolerance for the rod diameter.
In addition to the sealing function, rod seals also provide a thin lubrication film on the piston rod that lubricates themselves and the wiper seals. The lubricant also inhibits corrosion of the piston rod surface. However, the lubrication film must be thin enough so that it returns to the cylinder during the return stroke.

SKF ROD PROFILES
Product
Profile
Description
Datasheet
S1S

Single-lip U-cup profile made of polyurethane; suitable for medium to heavy duty applications
ZBR

Double-lip U-cup profile made of polyurethane; suitable for medium to heavy duty applications
SIL

Double-lip U-cup profile made of polyurethane; suitable for low temperatures and light to medium duty applications
PTB

PTB profiles are made of LUBRITHANE (TPU). They are suitable for pressures up to 400 bar (5 800 psi) in medium duty applications and are available in metric and inch sizes. Some metric sizes fit seal housings in accordance with ISO 5597:2010.
STD

STD profiles are made of LUBRITHANE (TPU). They are suitable for pressures up to 400 bar (5 800 psi) in medium duty applications and can also be used as a heavy duty static seal or a snap-in wiper seal. These profiles are available in inch sizes where narrower seal housings are used.
DZ

DZ profiles combine an NBR primary sealing ring with a LUBRITHANE (TPU) secondary sealing ring into one seal. This combination provides a good low temperature resilience and is suitable for pressures up to 400 bar (5 800 psi) in medium to heavy duty applications.
DZR

Nitrile rubber primary sealing ring, polyurethane secondary sealing ring, integrated triangular polyamide anti-extrusion ring; improved gap extrusion resistance; suitable for heavy duty applications and extreme pressures
SKF BUFFER SEAL PROFILES
Product
Profile
Description
Datasheet
RBB

Buffer seal with nitrile rubber O-ring energizer, PTFE slide ring; also available with polyurethane slide ring to improve wear resistance and ease installation; suitable for medium to heavy duty applications
S9B

Buffer seal with PTFE slide ring, nitrile rubber energizer; patented and improved design to reduce pressure peaks acting on the rod seal and vent pressure back to system side; improved gap extrusion resistance at abrupt pressure peaks; suitable for medium to heavy duty applications
RSB

Buffer seal with polyurethane sealing ring, integrated polyacetal or polyamide anti-extrusion ring; designed to vent pressure back to system side; improved gap extrusion resistance at abrupt pressure peaks; fits narrow housings; suitable for heavy duty applications