Type 48VBF John crane

O-ring Pusher seals | Low leakage, high temperature shaft seal for uncooled boiler-feed-water

Type 48VBF John crane

Features mechanical seal type 48vbf

  • California Residents: PROPOSITION 65 WARNING
  • Plans such as 23 or 21 with heat exchangers are not required
  • Rotating mating ring design for reduced misalignment and higher shaft speed capability
  • Mating ring outer diameter surfaces entirely exposed to process fluid for enhanced heat transfer

About Mechanical seal type 48vbf

The Type 48VBF is a single seal that can operate without a cooling water system (external heat exchanger, API Plan 23) in critical high temperature pumps. In systems such as boiler feed water (hot, demineralized, deaerated water) for fossil-fuel steam power plants or within the utilities section of a process plant, can simplify operations and significantly reduce water consumption.

Marginally cooled or even uncooled, the Type 48VBF can run 20 °C hotter than competitive solutions, so will run longer in marginal conditions. Using advanced face technology and assembly techniques, unique “hydropads” allow the seal faces to remain flat in operation, increasing lubrication efficiency and so enabling the seal to run cooler.

The 48VBF is an easy upgrade from the existing John Crane 48V seal, requiring nothing more than changing the primary ring.

Design Features mechanical seal type 48vbf

Primary ring– high duty carbon-graphite grade for tolerance to difficult sealing conditions found in hot water services.

Unique design – proprietary patent pending hydrodynamic features to allow sealing hot water far above its atmospheric boiling point while minimizing leakage. Allows operation on hot water without cooling.

Rotating mating ring design – enhances cooling and permits use at higher shaft speeds, often required in power plants.

Compatible – Fits API seal chambers, and interchangeable with existing John Crane seals on similar applications.

Easy upgrade – Existing commonly used 48V seal may be upgraded to 48VBF by simple change of primary ring

Robust drive mechanism – The primary ring incorporates an optimized ear drive design for increased torque capability

Operating range mechanical seal type 48vbf

  • Temperature: 0°C to 200°C/32°F to 392 °F
  • Pressures: Carbon Face: Up to 30 bar g/435 psi g
  • Speed: Up to 30 m/s/5900 fpm

Product Description type 48vbf

The 48VBF seal is a single cartridge, stationary head, O-ring pusher seal that can operate without an external heat exchanger (API Plan 23) in critical high temperature, medium pressure pumps. This is ideal for application in Boiler Feed pumps, which inject feedwater (hot, demineralized, deaerated water) into the boiler at fossil-fuel steam power plants or within the on-site generation plant of a processing or manufacturing site.

The main risk of seal failure is due to numerous problems associated with the heat exchanger seal support loop, resulting in the BFW pump shutting down and the boiler going offline. Common heat exchanger support loop problems include:

• Loss of cooling water
• Undersized heat exchanger
• Incorrectly installed/located heat exchanger and/or piping
• Poor/inadequate venting procedure after outages/shutdowns
• Scale/corrosion build-up within the piping, limiting flow and seal cooling

By allowing operation without that heat exchanger, the 48VBF reduces cost to the end-user for the heat exchanger, piping and water usage.