Double-acting mechanical seal with 20 mm shaft diameter for size 1 homogenisers from Vakumix and NETZSCH Vakumix – suitable for plants with approx. 15 to 100 litres batch size and for circulation agitators in pre-phase vessels. Price: EUR 2,001.72 net (EUR 2,382.05 incl. 19% German VAT), plus shipping of EUR 49.95 per seal (insured express, Germany).
Delivery time approx. 1 week (dispatch after 3–7 working days). Sales exclusively to business customers.
Compatible – not an original part: This mechanical seal is a bought-in part from specialised seal manufacturers and fits homogenisers from NETZSCH Vakumix and Vakumix. It is not an original part and this is not an offer from NETZSCH or Vakumix.
Typical applications of the 20 mm seal
The mechanical seal with 20 mm shaft Ø belongs to size 1 homogenisers. These are found in smaller production and pilot plants with batch sizes of around 15 to 100 litres – for small series, sample batches and product development of creams, ointments and gels.
- Smaller production and pilot plants
- Frequent product changes with many cleaning cycles
- Also suitable for circulation agitators with a 20 mm shaft
Technical data
| Feature | Mechanical seal 20 mm |
|---|---|
| Shaft Ø | 20 mm |
| Homogeniser size | Size 1 |
| Batch size of the plant | Approx. 15 to 100 litres |
| Design | double-acting |
| Housing | V4A stainless steel |
| Seal rings | 4 × silicon carbide (SiC), alternatively e.g. carbon against chrome cast iron |
| O-rings | FKM, others e.g. EPDM on request |
| Suitable for | Homogenisers from Vakumix and NETZSCH Vakumix, circulation agitators in pre-phase vessels |
| Price | EUR 2,001.72 net · EUR 2,382.05 incl. 19% VAT |
| Delivery | delivery time approx. 1 week, insured express shipping within Germany EUR 49.95 per seal |
Why silicon carbide?
Silicon carbide (SiC) is particularly wear-resistant – even with abrasive raw materials. That is why the standard version uses four SiC seal rings. Other material pairings are possible for special applications.
Replace seal and shaft together
If the mechanical seal is leaking, the shaft should be checked too: with increasing age, imbalance can occur, and the shaft wears in the area of the seal. A new seal on an old shaft lasts much less long. We supply the matching shaft and fit both on request in our workshop in Weyhe or on site at your plant.
Service around your seal
- Damage analysis of every removed seal with a short report
- Testing after repair or fitting, on request with a test report
- Collection by courier and return delivery
- Exchange seal to avoid downtime
Frequently asked questions about the mechanical seal 20 mm
How do I know whether my homogeniser has a 20 mm shaft?
The type plate and plant documentation (homogeniser size 1) and a batch size of about 15 to 100 litres are good indicators. Measuring the shaft diameter in the seal area is the reliable way. You can also send us photos via the service request – we will check the fit.
When should the 20 mm mechanical seal be replaced?
Typical signs are leaks, product in the barrier fluid, unusual noise or increased temperatures in the seal area. With frequent product changes and cleaning cycles, regular checks during maintenance pay off.
Is there an exchange seal for the 20 mm size?
Yes. With an exchange seal your plant stays ready for operation while we examine the removed seal and send you a short damage report.
Other sizes
Last updated: October 2026
All trademarks and product names mentioned, in particular Vakumix, NETZSCH, LambdaVita, KappaVita and GammaVita, are the property of their respective owners and are used solely to identify the products offered. This is not an offer from the manufacturer. SEEFRIED Verfahrenstechnik is an independent supplier and is not affiliated with these manufacturers; the mechanical seals offered are compatible spare parts, not original parts.