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Seal Supply Systems

Product Description

  • BFS2000 thermosiphon system makes it
    possible to supply buffer/barrier fluid to a
    double and a tandem mechanical seal for a
    broad range of applications.
  • The range is available in different pressure
    levels with dished heads, sight-glass for level
    monitoring and with or without cooling coil.
  • BFS vessels are equipped as standard with all
    the necessary system connections and
  • The modular system allows the BFS 2000
    vessels to be combined with a wide range of
    system components such as, level switch,
    circulation pump, hand refill pump,
    thermometer, base frame, etc.
  • Circulation in accordance with API 682/ISO 21049


Item No. Description
1 Buffer/barrier fluid IN (G1/2")
2 Buffer/Barrier fluid OUT (G1/2")
3 Cooling water IN (G1/2")
4 Cooling water OUT (G1/2")
5 Filling connection with plug (G1/2")
6 Pressure gas connection (G1/2")
7 Connection for level switch or level indicator (G2")
8 Connection for refill unit (G1/8")
9 Universal connection (G1/2" for safety valve, flare, etc.)
10 Bracket for refill unit
11 Sight-glass

Technical Features

  • Available with or without cooling coil.
  • Cooling water connections at top (OUT) and
    bottom (IN): optimum draining and venting.
  • Sockets with recessed gasket : no
    contamination of the circuit by thread sealant.
  • Suitable for a wide range of demanding
    operating conditions: BFS 2000 up to 30 bar /
  • Vessel made of 316 stainless steel /
    borosilicate sight-glasses: suitable for
    universal applications.

Operating and Installation Schematic

The BFS vessel must always be installed higher than the mechanical seal. The buffer/barrier fluid flows via the return pipe into the vessel and is cooled. The exchange of fluid takes place by the thermosiphon principle or by forced circulation, e.g. with a pumping screw. Connection pipes to the seal should be designed with as little resistance as possible.

  • Measuring unit
  • Level Switch
  • From PCV, we recommend using a reverse controlled
    pressure control valve (PCV)
  • Hand Refill Pump
  • Circulating Pump
  • Mechanical seal

Typical Industrial Applications

  • Chemical industry
  • Oil and gas industry
  • Petrochemical industry
  • Refining technology


PED 97/23 EC (Design and production in accordance
with EU Pressure Equipment Directive)
ASME VIII, Div. 1 (Design, calculation and production)

Functional Description

The BFS system performs all the basic functions of a buffer/barrier system for the operation of double seals:

  • to pressurize the buffer chamber
  • leakage compensation
  • buffer/barrier fluid is circulated by thermosiphon effect
    or external circulation system
  • to cool the seal
  • to selectively absorb product leakage and prevent dry
    running (tandem arrangement)
  • Use compressed air or nitrogen for pressurization.
  • Circulation in accordance with API 682 / ISO 21 049:
    Plan 52, Plan 53A

Standard Cartridge Seals

Mechanical Seals As Per API 682

Split Seals

Engineered Seals For Demanding Applications

Standard Mechanical Seals For Pumps & Compressors

Mechanical Seals For Agitators, Mixers, Kneaders & Reactors

Supply Systems & Components

API 682 / ISO 21049

Technical Information