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Piston rings/sealing rings
Piston rings optimized for function and longevity. Select from various materials, coatings, and cuts. All rings feature phosphating for improved run-in and durability
Piston rings optimized for function and longevity. Select from various materials, coatings, and cuts. All rings feature phosphating for improved run-in and durability
Features of piston rings
features
A segment is characterized by 8 criteria: material, cross-section, peripheral reach, stops and shoulders, coating, spring, cutting and surface treatment which will be chosen step by step to enable to find the ring best suited.
Each material for the ring should be chosen depending on the specific pressures, operating temperatures, its function and the life expectancy.
There are several cross sections, the rectangular section fulfils all sealing functions. The K and HK sections allow a long segment life. The L-shape improves the contact of the lower edge on the cylinder in the 2 stroke engines and gives increased safety to the beats.
The outside diameter is important as it allows to control the passage of oil in the segment. The type B is optimised for running in and favours a good spread of the oil film at the top of the cylinder. The conical form (M), whilst increasing the specific pressure of contact, accelerate the running in and sealing. Also allows to regulate the oil consumption. On the oil control rings, the conical shape of the contact between the outside dia of the ring and the cylinder allows a very good control of the oil film thickness, in particular in compressors.
The radii and shoulders have each a different specification. The outside chamfers(KA) allows for passing past the openings on a 2 stroke motor, and facilitates the assembly but also increases the specific pressure by the reduction of the contact area. The external chamfers (KI) should only be used for safety reasons or assembly. radii at the back of the groove) The shoulders (IF or IW), when modifying the specific contact pressure on the height of the ring, will perform as a rectangular shape as well as a conical ring.
The coating is chosen depending on the life expected of the ring and of any difficult friction constraints (1° throat), the coating of hard Chrome (CR) can be specified.
The specific contact pressure (p) of the ring with the cylinder can be increased by introducing a spring in the shape of a spiral (SF) in the groove of the ring or by inserting a steel blade between the groove of the ring and the bottom of the throat. This technique is employed on the slotted oil control ring (S,G and D) and on the compression rings for 2 stroke motors.
Each cut of a segment is used for a specific line of business. Vertical cutting (VER) meets all thermal and compression uses. Oblique cuts (OBG and ÔBD) are intended to reduce the possible wear of the cylinder by the slats of the segment. Bayonet (SV) and hook (SH) cuts are only used in hydraulics. They have virtually no effect on sealing. The hooks offer ease in the case of complex mechanical mounting. The notches (NE and NH) are used in the segmentation of 2-stroke engines and allow the segment to be indexed on a pin.
Phosphating of the ring improves running in and insures an excellent protection against oxidation.
Segment type
Cuts
The rings are supplied with a play at the cut/joint adjusted to the specification of the customer or by default to the ISO norm. However, it is possible to supply non adjusted, meaning that the edges will be end to end when the ring will be closed in the piston groove. In this case, the ring will be referenced NAC (Non Adjusted at the Cut).
