Molded of 55D Durometer Hytrel, these back-up rings provide excellent extrusion resistance and tolerance to fluids such as phosphate esters, hydraulic oil and water. Stretched for installation, they return quickly to their original size for easy installation.
NOTE: Sizes (Dash No.) corresponds to standard O-ring numbers

Molded of 95A Durometer Urethane these back-up rings provide excellent extrusion resistance. Stretched for installation, they return quickly to their original size for easy installation.
NOTE: Sizes (Dash No.) corresponds to standard o-ring numbers.

NOTE: The 6000 piston cups are center punched if there is no hole size indicated.

To obtain best results from any style of piston cup, it is recommended that the piston properly support the heel of the cup. Recommended diametral clearance between the piston and cylinder wall are as follows:
1" to 2-1/4" .005"
2-1/2" to 4-3/4" .008"
5" to 10" .010"

The height of the machined shoulder most frequently used to control squeeze on the heel of the cup is as follows:
Cups 1/8" thick .116/.119"
Cups 5/32" thick .146/.149"
Cups 3/16" thick .178/.181"
The follower plate should be approximately .110" smaller than the ID of the cup. To reduce any tendency of the cup to extrude under pressure a phonograph finish may be machined on the surface of the follower plate.

NOTE: The 8000 piston cups are center punched.

If your design is of medium to high pressure it is recommended that you utilize fabric reinforced rings. The following is a guide to pressure rating of multiple rings, including flat bottom rings.

A homogeneous ring may be also used for sealing at low pressure. Do not include the homogeneous ring in calculating pressure rating. Due to the different material, it is difficult to rate this type of ring. If you wish to use all homogeneous rings, tests should be conducted to verify design stability.

If your design is of medium to high pressure it is recommended that you utilize fabric reinforced rings. The following is a guide to pressure rating of multiple rings, including flat bottom rings.

A homogeneous ring may be also used for sealing at low pressure. Do not include the homogeneous ring in calculating pressure rating. Due to the different material, it is difficult to rate this type of ring. If you wish to use all homogeneous rings, tests should be conducted to verify design stability.

• MATERIAL 70A BUNA-N RUBBER
• TEMPERATURE RANGE -40° to +240° F
• PRESSURE RANGE 0 to 500 PSI
• SPEED 3 FT/SEC
• PART NUMBER (Prefix)(CS) - (A-N Dash Number)

Piston cups are constructed of rubberized fabric. Cups with no hole are center punched.
NOTE: If Product number ends in 'ED' the piston cups are specially sized for use in EDBRO Cylinders.

INSTALLATION OF PTFE PISTON SEALS
Installing PTFE piston seals is not always an easy task. The use of installation tools (Designated by a 'CTC-' product code prefix) is recommended but often not convenient when working with a wide variety of sizes and applications. Finger installations are practical with rings of smaller cross-sections. Using fingers or a rounded plastic stick, knead the ring over the piston into the groove. With rings of larger cross-sections it may be necessary to heat the ring. Warming the ring in water or oil at 130° F or 140° F for about 5 minutes will soften the material for easier installation. Always avoid inconsistent stretching or overstretching of the PTFE seal.

To prevent the PTFE ring from snapping into the wrong groove, cover wear ring grooves with plastic tape.

After seal installation, assembly of the cylinder may be difficult if the piston seal is loose on the piston or the cylinder has an inadequate leading edge chamfer. In such cases, compress the piston seal with belting or a suitable hose clamp. If the piston seal must pass threads or any other sharp edges during the cylinder assembly, cover the edges with plastic tape or wrap. Note: Caterpillar part number are used as a refernce only. We do not imply that these part are original equipment parts.

A heavy duty double-acting assembly, the capped piston T-seal exhibits excellent sealability, extrusion resistance and wearability. T-seals with 'BR' suffix utilize a Bronze Filled PTFE cap instead of the standard Glass Filled PTFE cap.

INSTALLATION OF PTFE PISTON SEALS
Installing PTFE piston seals is not always an easy task. The use of installation tools (Designated by a 'CTC-' product code prefix) is recommended but often not convenient when working with a wide variety of sizes and applications. Finger installations are practical with rings of smaller cross-sections. Using fingers or a rounded plastic stick, knead the ring over the piston into the groove. With rings of larger cross-sections it may be necessary to heat the ring. Warming the ring in water or oil at 130° F or 140° F for about 5 minutes will soften the material for easier installation. Always avoid inconsistent stretching or overstretching of the PTFE seal.

To prevent the PTFE ring from snapping into the wrong groove, cover wear ring grooves with plastic tape.

After seal installation, assembly of the cylinder may be difficult if the piston seal is loose on the piston or the cylinder has an inadequate leading edge chamfer. In such cases, compress the piston seal with belting or a suitable hose clamp. If the piston seal must pass threads or any other sharp edges during the cylinder assembly, cover the edges with plastic tape or wrap.

NOTE: Caterpillar part numbers are used as a reference only. We do not imply that these parts are original equipment parts.

These seals are specifically designed with a second lip on their inside diameter and engineered to attain maximum life and reliability in dynamic rod sealing. This feature results in reduced leakage, less friction, increased stability and prevents air and contaminants from entering the cylinder.

These seals are specifically designed to seal on their inside diameter and engineered to attain maximum life and reliability in dynamic rod sealing.