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Flowserve-Flowserve-Pusher Seals - QB

Pusher Seals - QB

BRAND: Flowserve

QB Series seals are balanced pusher seals available in single and dual seal configurations used for sealing environmentally-restricted products and meeting the most stringent regulations. The QB Series is fully compliant with API 682 Type A requirements.


  • Chemicals
  • Water
  • Oil & Gas
  • Power

industry sectors

  • Basic (Organic & Inorganic)
  • Water
  • Desalination
  • Downstream Processing
  • Nuclear
  • Conventional Steam
  • Combined Cycle
  • Biomass and MSW

API 682

Operating Parameters
  • Pressure: up to 51.7 bar (750 psi)
  • Temperature: -40° to 204°C (-40°F to 400°F)
  • Speed: up to: 23 m/s (75 fps)
  • Sizes: 12.7 to 139.7 mm (0.500 to 5.500 inch)
Features & Benefits
  • Greater reliability and installation ease assured by rugged components, heavy duty seal faces, and cartridge seal configuration
  • Satisfies all API 682 design and qualification test requirements for single and dual arrangement seals
  • Optimal face cooling and reduced distortion with available multiport injection
  • Increased safety and environmental compliance assured by dual seal arrangement, which provides for safety backup and emissions control in hazardous services
  • Longer equipment life and reliability from design that runs cooler and is less sensitive to vapor pressure margin, even under upset conditions
  • Combat dirty services with the clog-resistant large, single coil spring in the QBS seal
  • Handle low lubricity hot water without the need for auxiliary cooling systems with the QBU seal
  • Handle vaporizing hydrocarbons with the QBQ seal
  • Handle low vapor pressure margin with the QBQ LZ seal, featuring Precision Face Topography wave pattern on the stationary seal face
  • Low to moderate pressurized barrier dual seal applications are handled by the QBB face-to-back configuration
  • Moderate and high pressure pressurized dual seal applications, including Piping Plan 53B, are handled by the QB2B back-to-back configuration
  • Choice of throttle bushing design: fixed, floating, or segmented

Arrangement 1 single seal (Common Piping Plans 11, 13, 23, 32, 62)

Arrangement 2 unpressurized dual wet seal (Common Piping Plans 52)

Arrangement 2 unpressurized dual seal with dry running backup (Common Piping Plans 72, 75, 76)

Arrangement 3 pressurized dual wet seal (Common Piping Plans 53A, 53B, 53C, 54)


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