Handling the heat and the pressure

FS seal
FS-seal detail
The FS-seal is a relatively large cross section spring energized rubber casing and tubing hanger seal for wellheads that always has the springs on the internal surface.
FS-seals are used against rough surface finish and wider dimensional and geometrical tolerances of casing and tubing.
Sealing materials utilized for wellheads need to withstand pressures as high as 1 034 bar (15 000 psi) and temperatures of 149º C (300º F).
All our FS-seals successfully passed the test according to API 6A annex F PR2 with the following parameters:
  • Gas test pressure: 0 to 690 bar (0 to 10 000 psi)
  • Temperature: -18 to 121 °C (0 to 250 °F)
  • Test medium: Nitrogen gas


  • Improved equipment reliability
  • Extended seal and equipment service life
    Reduced installation time, delay and damage
  • Protects system from loose materials

FS-seals are available as moulded versions made of SKF Ecorubber-H 85A-b-ED.

Please see more details about materials here.

Please see the wellhead seal selection criteria here.

FS-seal part number


MMSA    ...    FS-seal

10         ...    Cross section for diameters 4" - 97/8"

11         ...    Cross section for diameters 103/4"

12         ...    Cross section for diameters 113/4" - 16"

4500     ...    Casing diameter (4000 up to 18625)

K4P       ...    Material SKF Ecorubber-H 85A-b-ED with stainless steel spring

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