DESCRIPTION
The UH-Z and UH-DZ styles are also know as the SKF/Polyseal Z-Seal™. These seals are pre-loaded with a molded, Nitrile sealing lip that evenly distributes pressure from 0 to max psi. The sealing lip provides its own compressive seal force under low-pressure conditions, but as pressure increases, the hydrostatic pressure is transmitted through the sealing element to the urethane base. The design of the molded sealing lip deflects radially onto the locking lobes under pressure completely closing the extrusion gap behind the sealing lip.
The shell is molded in Lubrithane, ensuring flexibility for installation and high/low pressure performance. Maximum temperature is 220F.
This seal is also available in a Fluorotrel shell which is a tough, wear-resistant material able to run at temperatures of -65F to 275F. Fluorotrel is also resistant to fluids that are incompatible with polyurethane such as water, glycol, water in oil, mineral oil and petroleum. A low-temp Nitrile sealing lip is recommended for temperatures below -40F. For high-temperature applications, the standard Nitrile sealing lip is recommended for temperatures up to 265F
This seal is available in the following common styles: UH-Z Nitrile sealing lip with polyurethane support base UH-DZ Same as UH-Z except the polyurethane support base serves as secondary sealing lip UH-DZL Same as UH-DZ except with low-temp Nitrile sealing lip UH-DZR Same as UH-DZ except Nylon anti-extrusion ring incorporated in ID heel of the polyurethane shell for higher pressure and more severe hydraulic service. Rated to 7,000 to 10,000 PSI depending on temperature and extrusion gap. UH-DZLF Low-temp Nitrile sealing lip with Fluorotrel support base that serves as secondary sealing lip
SEAL INFORMATION
Material Type (Primary Seal): NITRILE (OR LOW-TEMP NITRILE
Material Type (Base): POLYURETHANE OR FLUOROTREL
Durometer (Shore A): 70
Durometer of Base (Shore A): 95 (URETHANE)
Durometer of Base (Shore D): 55 (FLUOROTREL)
Temperature Range (F) POLYURETHANE + NITRILE: -40 TO 230
Temperature Range (F) FLUOROTREL + LOW-TEMP NITRILE: -65 TO 265
Max Pressure (psi): 5,800 / 10,000
Extrusion Gap at Various Pressures (in):
- 4,500 PSI: 0.020
- 5,000 PSI: 0.015
- 10,000 PSI (DZR ONLY): 0.020
Max Speed (ft/sec): 3.0
Mating Surface Roughness - Ra (µin) - DYNAMIC: 4<>16
Mating Surface Roughness - Ra (µin) - STATIC: 63 MAX
Part Number Definition (Inch): UH-(CS)(ID)(HT)(DESIRED STYLE)
Additional Part Number Definition (Inch): 2 X 2-1/2 X 3/8 = UH-25002000375Z (OR UH-25002000375DZ)