BT-FH Balanced

BT-FH Balanced
Item Description
1 Seal face
2 Stationary seat
3, 3a, 3b O-Ring
4 Spring
5 Collar
A Spacer (upon request)

BT-FH Balanced


  • Single pusher-type seal
  • Balanced
  • Dependent on direction of rotation
  • Conical spring
  • Length according to EN 12756
  • Version NB (normal length, balanced L1NB)


The BT-FH mechanical seal range has been designed for universal application and is ideally suited for standardization. It is a cost-effective version of a balanced seal with the added advantage of only having to replace the wearing faces during overhauls. Installation length in accordance with EN 12756 (L1NB).

Operating range

Shaft diameter:
d1 = 16 … 70 mm (0.63" … 2.76")
Pressure: p1* = 25 bar (363 PSI)
t* = -35 °C … +180 °C (-31 °F … +356 °F)
Sliding velocity: vg = 15 m/s (49 ft/s)

* Dependent on medium, size and material


Seal face: Silicon carbide (Q1)
Seat: Carbon graphite resin impregnated (B), Carbon graphite, full carbon (B3), Carbon graphite antimony impregnated (A), Silicon carbide (Q1)
Elastomers: NBR (P), EPDM (E), FKM (V), FFKM (K)
Metal parts: CrNiMo steel (G)

Standards and approvals

  • KTW
  • W270
  • ACS
  • WRAS
  • NSF
  • FDA
  • DM 174/04


Seat ring of alternative seats can be supplied with short tail or with pin to block the seat and prevent seat rotation.

Product variants


The BT-FH.NB DV is a variant of the BT-FH.NB with a vertical pin for torque transmission in the conical spring. Same installation length as BT-FH.NB, in accordance with EN 12756 (L1NB).