Type 48SC John crane

O-ring Pusher seals |Dry-contacting Secondary Containment Seal

Type 48SC John crane

Features mechanical seal Type 48SC

  • Shaft-mounted unit with a carbon primary ring and a specially shaped silicon carbide mating ring and drive collar designed to enhance cooling
  • Narrow radial section, simplicity and lower cost, making it an attractive option for many services

Recommended Applications Type 48SC

  • Process pumps
  • Other rotating equipment

About Mechanical seal Type 48SC

Dry-running, contacting seals employ a technology based on careful material selection and precise control of contact forces. They are designed to operate dry, with the containment chamber between the seals being vented to a flare or vapor recovery system.

Design Features mechanical seal Type 48SC

For easy outboard seal replacement from existing liquid lubri-cated tandem arrangements to dry sealing.

• For (Maximum Achievable Control Technology (MACT) compliant emission control use in conjunction with Type 48sc.

• Available in short seal designed to fit ANSI and older edition API pumps where there is restricted axial length (Type S48SC).

• 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.

• Primary ring has lightly-loaded springs to permit dry sealing at pump speeds. Lower spring rates keep load even over a wider working height range. Controlled O-ring squeeze and spring load minimizes seal head drag.

• Self-cooling performance is enhanced by  tapered back surface of mating ring, allowing greater access of air at seal faces and increasing surface area exposed to cooling air which is created by specially designed drive collar. Also contributing to low heat at faces are narrow face width, with controlled pressure and thermal distortion.

Material mechanical seal Type 48SC

  • Face/Primary Ring: Carbon
  • Seat/Mating Ring: Reaction Bonded Silicon Carbide
  • O-Ring: Fluoroelastomer
  • Disc: 316 Stainless Steel
  • Set Screws: 316 Stainless Steel
  • Retainer: 316 Stainless Steel
  • Snap Ring: 316 Stainless Steel
  • Springs 316 Stainless Steel

Operating range mechanical seal Type 48SC

Temperature Limits

32°F to 400°F/0°C to 205°C


Pressure Limits

Dry: 5 psi(g)/.35 bar(g)


Wet: 500 psi(g)/35 bar(g)


Speed Limits


Product Description Type 48SC

Self-cooling Type 48SC Seals are full contact dry-running secondary containment seals. This breakthrough in dry tandem sealing requires no external lubrication system, reducing hazards from buffer fluid contamination and eliminating contaminated fluid disposal problems. Available in retrofit kits, these secondary containment seals can fit into existing cartridges.

• For service in chemical processing, cryogenics, offshore plat- forms, oil production and refining, petrochemical processing, pharmaceutical, and pipeline transmission