Type-5281-john-crane

Vessel and Agitator seals | Heavy-duty Cartridge Seal for Boiler Feed Circuit Applications

Type-5281-john-crane

Features mechanical seal Type 5281 (W, D, G, GD)

  • California Residents: PROPOSITION 65 WARNING
  • Dual-pressurized cartridge seal for glass-lined vessels with rotating seat design inboard for optimal clean ability.
  • Modular design concept with interchangeable components.
  • Squared PTFE-based secondary sealing elements (PRP-Ring) improve clean ability and secure a broad chemical and temperature application range.
  • Design of standard version adapted from DIN 28138 considering qualified hygienic design criteria (QHD).
  • Product wetted materials are in compliance with FDA requirements for food contact.
  • Special designs or material options such as USP Class VI compliant polymers are available on request
  • Type 5281 is available in four variants of lubrication system:
    – 5281 W — Liquid-lubricated wet seal
    – 5281 D — Dry-running contacting seal
    – 5281 G — Gas-lubricated non-contacting seal
    – 5281 GD — Gas-lubricated non-contacting inboard, dry running outboard
  • Suitable for application in explosive areas.
  • Certificates of conformity according to
  • European Directive 94/9/EC (ATEX) Cat. 3, 2 or 1 on request.

Recommended Applications Type 5281

  • Mixer and agitators
  • Other rotating equipment

About Mechanical seal Type 5281 (W, D, G, GD)

Type 5281 is part of the 5280 hygienic vessel seal family. Please find general technical and hygienic design features of this family in the description of Type 5280. The Type 5281 was especially developed for applications on glass-lined reaction vessels with a glass-lined agitator shaft. To enable this, all product-wetted materials of the seal need to be of nonmetals. Due to the special design features of the 5280 seal family, this could be achieved by just building a silicon carbide insert into the cartridge flange. All other components and features are similar to Type 5280.

Design Features mechanical seal Type 5281 (W, D, G, GD)

  • Dual cartridge seal designed according to hygienic design criteria (QHD) with inboard rotating seat for optimal
    cleaning in place
  •  Squared PTFE-based secondary sealing elements improve
    cleaning and support a broad application range
  • Product wetted materials compliant with FDA requirements
  • Special designs and material options such as USP class VI
    compliant polymers are available on request
  • Reverse pressure capabilities inboard
  • Suitable for application in explosive areas. Certificates of
    conformity according to European Directive 94/9/EC (ATEX) Cat. 1,
    2 and 3 available on request
  • Available in four variants of lubrication system:
    – 5280/81/82 -W – liquid lubricated wet seal
    – 5280/81/82 -D – dry running contacting seal
    – 5280/81/82 -G – gas lubricated non-contacting seal
    – 5280/81/82 – GD – gas lubricated non-contacting inboard,
    dry running outboard
  • Special carbon materials allow for exceptional operation of gas
    seals with dry gas of pharmaceutical quality
  • Special bearing design for high performance of non-contacting
    gas seals
  • G design advantages include wear-free and particle-free
    operation, together with an easy supply system. In addition, the
  • GD design reduces barrier gas consumption

Operating range mechanical seal Type 5281

  • Temperature Limits
    -40°F to 392°F/-40°C to 200°C (-148°F/-100°C modified)
  • Pressure Limits
    Vacuum to 6 bar(g)
  • Speed Limits
    400fpm/2m/s
  • Size Limits
    40mm to 160mm

Product Description Type 5281

The first choice for ultra-clean pharmaceutical and biochemical applications, these seals meet Qualified Hygienic Design (QHD) requirements to enable the cleaning and sterilisation of the product wetted process area with the seal in place (CIP, SIP).

Different versions of the Type 5280 family are suitable for different vessel materials: Type 5280 for steel, Type 5281 for glass-lined and Type 5282 for special alloy vessels. Each version is available in liquid lubricated (W), gas lubricated (G), dry running (D) and a unique gas/dry face combination (GD) version. Although mostly
used in top-entry vessels, the inboard rotating seat design perfectly suits side and bottom-entry vessels.