Type JCS1 John crane

O-ring Pusher seals | Heavy-duty Cartridge Seal for Boiler Feed Circuit Applications

Type JCS1 John crane

Features mechanical seal Type JCS1

  • California Residents: PROPOSITION 65 WARNING
  • Balanced design provides undisturbed operation even with sudden pressure shocks.
  • Single spring on atmospheric side located in the stationary part of the seal. Material is corrosion-resistant. Shaft misalignment does not pulsate the spring or wear out the O-ring.
  • No measurements required for installation. Easy installation reduces risk of human error.
  • Seal installation does not require back plate removal, and the seal is fastened with one bolt which guarantees fast, trouble-free installation.
  • Torque transmission with super-elastic devices combined with no drive pins at seals faces. Seal faces do not crack at start-up.

Recommended Applications Type JCS1

  • Process pumps
  • Other rotating equipment

About Mechanical seal Type JCS1

Safeseal JCS1 is a rugged, pump-integrated single seal designed for clean and lubricating fluids such as water, oils, solvents and low-consistency paper stocks. The JCS1 seal is easy to install from the impeller side. JCS1 is very advanced in its technical capabilities, including a patented drive mechanism for seal faces and self-aligning, elastically mounted thrust ring.

The JCS1 is originally designed for Sulzer AHLSTARUP pumps and later expanded to cover Andritz process pumps and other equipment.

Several variants of the design available for different services:

CS1F – Single application-specific seal with flush into the medium

JCS1A – Single application-specific seal for Sulzer liquid ring pumps and Andritz ACP pumps

JCS1M – Single application-specific seal for Sulzer multistage pumps

JCS1G – Single application-specific grease seal

JCS1FM – Single application-specific seal with flush into the medium for Sulzer multistage pumps

Operating range mechanical seal Type JCS1

  • Temperature Limits

    JCS1 up to 194°F/90°C

    JCS1F up to 250°F/120°C


  • Pressure Limits

    225 psi(g)/16 bar(g)


  • Speed Limits



  • Standard Materials

    Seal faces: SiC/Carbon or SiC/SiC

    O-rings: PTFE, EPDM, Viton

    Metal parts: EN 1.4436/1.4460 (AISI 316/329)

    Springs: EN 1.4436 (AISI 316)