SPO (Plan 53B)

SPO (Plan 53B) For a larger view, please mouseover the image.
For a larger view, please mouseover the image.
SPB6002A4 with air cooler

A From mechanical seal
B To mechanical seal
C Fill
F Drain
H N2 Precharge
Pressurized barrier system (closed circuit) for use in seal systems with high pressures and/or for hazardous/environmentally harmful processes. The SPO (Plan 53B) range is available with a pressure accumulator, cooler (finned tube, water or air cooler with fan) and a wide range of instruments.

Circulation in accordance with API 682 / ISO 21049: Plan 53B
  • Pressurization is by means of a pre-loaded bladder accumulator
  • The nitrogen is separated from the barrier medium by membranes in the accumulator: nitrogen cannot get into the barrier medium or process medium
  • Barrier pressure is created without any need for connection to a nitrogen supply
  • Available with finned tube, water or air coolers with fan
  • Modular system: combination with a wide range of system components/instruments possible
  • PED 2014/68/EU (Design and production in accordance with EU Pressure Equipment Directive)
  • ASME VIII, Div. 1 (Design, calculation and production)
  • Petrochemical industry
  • Chemical industry
  • Oil and gas industry
  • Refining technology
The SPO is designed to perform the following functions of a barrier system:
  • to pressurize the barrier chamber
  • leakage compensation
  • to cool the seal


Pressurization (> process pressure) prevents the process medium from getting into the barrier circuit or the atmosphere. Pressurization is supplied by a pressure accumulator which is pre-loaded with nitrogen. Circulation in the barrier circuit takes place by the thermosiphon principle or by forced circulation, e.g. with a pumping screw.
A refilling unit has to be provided.