Mechanical seals according to standards

Acc. to factory standards, ISO and ANSI standards
  • single-acting
  • unbalanced
  • mech. seal with elastomer bellows, independent of direction of rotation
  • single spring
Dimensions: 10-100 mm
pmax: 12 bar 
t: -20C up to 100/200C
(acc. to elastomer material)
vmax: 10 m/s
  431 mech. seals are simple, solid seals with spring freely accessible to be flushed, for many applications, e.g. with waste water.

Fitting dimensions acc. to DIN 12756 (formerly 24960); deviations to DIN in the diameter range.

Style 431K is the most widely used version; further designs with longer bellows: style 431 and 431N (acc. to DIN L1K or DIN L1N).

Stationary seat in block shape with collar (style BM) as shown in the illustration or optional with DIN stationary seat (style DIN-KL) without torsion lock.

Mostly required elastomer materials: Viton® fluoroelastomers *), NBR, EPDM.

Different seal faces/ stationary seats available; see material chart.
  *) Viton® is a registered trademark of Performance Elastomers.

  • single-acting
  • balanced
  • independent of direction of rotation
  • multiple springs (protected)
  • outside the medium
Dimensions: 24-110 mm
(also in inches)
pmax: 10 bar
t: -80C up to 220C
(acc. to secondary seal)
vmax: 20 m/s
  As a seal outside the medium specifically suited for corrosive media, chemicals etc. - no metal parts in contact with medium; economical alternative to mechanical seal made of titanium, tantalum and similar material (as a single seal outside the medium, the safety aspect acc. to the medium in question is important!)

With special clamping ring fixing for applications on plastics-, carbon-, rubber or PTFE pump shafts

Simple checkout function and cleaning possibility, as this mechanical seal is fixed outside the medium; also very suitable for installation in two-bearing pump

Stationary seat: L-shape acc. to ISO 3069

Materials:seal face (solid) :
SIC or B2 carbon stationary seat (solid): ceramics 99.7 or SIC
For secondary seals see material chart

  • single-acting
  • balanced
  • independent of direction of rotation
  • multiple spring (protected)
Dimensions: 18-150 mm
(also in inches)
pmax: 28 bar
t: -25C up to 205C
(acc. to secondary seal)
vmax: 15 m/s
  As stationary seat use stationary seat according to DIN or ISO-L shape.

Balance by means of integral protective sleeve, thus no step in shaft sleeve or shaft is required - installation on even, passing shaft/ shaft sleeve. No scoring or fretting of shaft-/ protective sleeves.

Cross-section of style 900 is so designed that the mechanical seal fits into packing stuffing box compartments without any changes - conversion of pumps formerly equipped with packings to mechanical seals is easy to achieve.

  • single-acting
  • balanced
  • independent of direction of rotation
  • multiple springs (protected)
Dimensions: 18-110 mm
(also in inches)
pmax: 30 bar
t: -25C up to 250C
(acc. to secondary seal)
vmax: 25 m/s
  L-shaped stationary seat acc. to ISO 3069 or with CHETRA DIN-SEG stationary seat acc. to DIN 12756 and adapter

As further development of CHETRA mechanical seal style 900 with application of solid seal face

Pressure relief by means of integral protective sleeve for passing even shaft/ shaft sleeve: no scoring or fretting of shaft-/ shaft protective sleeve

Suitable for conversion from packing to mechanical seal because of dimensions; fits into packing stuffing box compartments practically without any changes

  L-shaped stationary seats acc. to ISO3069
B1 acc. to ANSI s. Stationary seats