Type 8648SC | John Crane
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Type 8648SC

Non-pusher Dry running Secondary Containment Seal

The John Crane 8648SC is a standardized non-pusher elastomer, dry running, secondary containment seal designed specifically for non-crude oil hydrocarbon services, with a focus on meeting the demanding requirements of pipeline pumping station duties.

The main risk of seal failure in these applications is due to the numerous problems associated with the secondary dynamic O-ring, potentially resulting in hang-up, fretting or stub sleeve wear. The design of the 8648SC completely eliminates these common problems.

The 8648SC is used in tandem with a primary seal such as the 8648VRS. The 8648SC performs in response to the primary seal leakage or failure. In the event of the seal coming into contact with the process fluid, the faces will close and prevent a mass escape of this fluid. This represents a less complex alternative to dual unpressurized seals using a API Plan 52.

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  • California Residents: PROPOSITION 65 WARNING
  • Unique proven secondary seal technology prevents wear to the sealing diameter and prevents secondary seal hang-up
  • Non- compressible flexible elastomer bellows
  • For easy outboard seal replacement from existing liquid lubricated tandem arrangements to dry sealing
  • The primary ring/face is a John Crane proprietary carbon grade developed specifically for dry-running systems. The mating ring is highly thermal conductive silicon carbide
  • Axially compact and easy to install seal head assembly
  • Balanced design and premium face materials enables high pressure capability
  • Ear drive design on primary ring increase drive torque capability
  • 90 shore elastomer for robust construction
  • No O-rings in the pusher head assembly to fret under pump shuttling
  • Simplified dual containment using plan 72 enables remote operation


Temperature Limits

-20°C to 204°C/-4°F to 400°F

Speed Limits

Up to 6,000fpm/31.5m/s Non-Crude


Up to 40 psig / 2.8 bar g (Dry Running Operation)
Up to 1450 psig / 100 barg (Containment Operation)

Recommended Applications

  • 原油管道泵
Works with:
Type 8648VRS Type 8648VRS
PG 72 PG 72

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