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API Plan 53A Barrier Fluid Seal Pot Pressurized by Nitrogen

API Plan 53A utilizes a reservoir and circulates a pressurized barrier fluid between the inboard and outboard seals. The typical source of pressurization is plant nitrogen. The reservoir should be set at least 20 psi (1.3 bar) above maximum seal chamber pressure. This is to ensure that leakage across the inboard seal face is barrier fluid which then lubricates the seal faces and passes into the process. For this reason, barrier fluid must be chemically compatible with the process fluid and process dilution not a concern. In order to provide positive circulation through the support system and into the seal, a pumping ring is employed. A reservoir level indicator or level transmitter shows both inboard and outboard seal leakage.

Plan 53APlan 52 
API Plan 53A Assembly and API Plan 53A Kit
Assembly and kit shown with some optional components.

This plan:

  • Provides additional heat removal from inboard seal when required
  • Is used with a dual seal arrangement when process leakage to atmosphere cannot occur

Plan 53A is available as a seal pot assembly. The associated field installation kit for use in connecting the assembly to your system is also available. Assembly contents may include:

  • Swagelok tube fittings
  • 63 series ball valves
  • CH series check valve
  • V series 2-valve manifold
  • QTM series quick-connects
  • Bimetal thermometer
  • TTW series thermowell tee
  • PGI series gauges
  • KHF series pressure regulator
  • Swagelok pipe fittings
  • Pressure transmitter
  • Level transmitter
  • Level switch
  • Seal pot

See page 35 of the Mechanical Seal Support Systems Application Guide for additional details and ordering information. Contact your authorized Swagelok sales and service center for information on optional components.

Contact your Authorized Sales and Service Center Back to Between Seal Plans