Epoxy.com Product # 5000
Expansion Bearing
DESCRIPTION:
The Epoxy.com #5000 Expansion Bearing is composed of an upper unit, a thin, stainless steel plate bonded to a sole plate and a lower unit composed of Teflon bonded to a durable, resilient fiber-free pad. Sliding or translation occurs between the stainless steel and the Teflon while deflection, rotation and load distribution are accommodated by the resilient pad. Complies with AASHTO standards.
UPPER UNIT:
Sole Plate: The sole plate shall conform to ASTM A-36, and the dimensions will comply with the details as shown on the structural drawings. All exposed surfaces must be given a prime coat of Epoxy.com #1200 two-component, zinc rich primer.
Stainless Steel: The stainless sheet shall be no less than 12 gauge, meeting ANSI, type 304 (ASTM A-240) specifications and have a mirror finish of less than 10 micro-inches R.M.S. (Root-Mean-Square) on the side in contact with the teflon. The stainless steel shall be a minimum of 1/4" smaller than the sole plate all around, and these shall be bonded together with a high temperature-resistant epoxy adhesive, or welded.
Epoxy: The epoxy adhesive shall meet the following requirements:
| REQUIREMENT | TEST METHOD | VALUE |
| Flexural Modulus | ASTM D 790 | 2 x 104 |
| Safe Operating Temp. | - 60° to 145°C | |
| Linear Expansion Co-efficient | ASTM D 696 | 4.8 X 105 |
| Bond Strength Tensile Shear at 77°F |
ASTM D 1002 | 1000 p.s.i. |
LOWER UNIT:
TEFLONŽ: The Teflon, self-lubricating bearing element shall be 1/4" thick and composed of 100% virgin (unfilled) polytetrafluorethylene polymer and shall meet the following requirements.
| REQUIREMENT | TEST METHOD | VALUE |
| Hardness, Shore D | ASTM D 2240 | 60 + 5 |
| Tensile Strength, p.s.i. | ASTM D 1457 | 2800 (min. avg.) |
| Elongation, % | ASTM D 1457 | 200 (min. avg.) |
TEFLONŽ is a registered trademark of the DUPONT Corporation.
| REQUIREMENT | TEST METHOD | VALUE |
| Deformation Under Load | ||
| %, 78°F, 2000 p.s.i. (1/2" X 1/2" X 1/32") |
ASTM D 621 | 4 (max.) |
| Specific Gravity | ASTM D 792 | 2.14 to 2.21 |
BEARING PAD:
The resilient fiber-free pad shall meet the following requirements:
ELECTRICAL PROPERTIES:
| Resistivity | Volume Resistivity 23°C 50% RH, Ohm-CM |
8.3 x 1010 | |
| Surface Resistivity | 23°C 50% RH, Ohm | 4.0 x 1012 | |
| Resistivity | Impressed Voltage - 500 | ||
| Dielectric Constant | 23°C 50% RH, Frequency |
||
| 60 cps | 8.55 | ||
| 103 cps | 7.82 | ||
| 106 cps | 6.0 | ||
| Dissipation Factor | 23° 50% RH Frequency |
||
| 60 cps | 0.089 | ||
| 103 cps | 0.060 | ||
| 106 cps | 0.087 | ||
| Dielectric Strength | Electrodes 1" apart 28°C oil temperature 500 vps rate of rise volts/mil 330 |
||
Tolerances: The expansion bearing total thickness will be +10%. The PTFE thickness shall be -0 + 1/64"
Co-Efficient of Friction: The co-efficient of friction between the self-lubricating bearing element (PTFE) and the stainless steel shall not be more than 0.06 at 800 p.s.i. compressive loading.
PHYSICAL REQUIREMENTS:
| TEST METHOD | VALUE | |
| Hardness, Shore A | ASTM D 2240 | 90 +/- 5 |
| Deflection | MIL-C-882C | 800 psi-7%max. |
| Volume Swell | FED-STD-601 | 1 max. |
| Method 6211, except immersion period shall be 24 + 1/4 hrs. The immersion medium shall be diesel oil in accordance with Type I of MIL-F-16884 | ||
| Deformation | MIL-C-882C Mod. | 15,000psi w/o Detrimental deformation. No ruptures |
| Permanent Set | MIL-C-882C Mod No Fabric Required |
2000 psi- 2.0% max |
| Tensile Strength | ASTM D-412 | 5,500 psi min |
| Ultimate Elongation | ASTM D-412 | 250%-min |