A stator, or stator ring, is the part of a mechanical seal that sits in the pump cover. As the name suggests, the stator ring is the static part of the mechanical seal. It consists of a metal, carbon (graphite) or ceramic (silicon carbide, tungsten carbide) ring with an O-ring. The O-ring is an important part of the stator, because it ensures the seal between the pump housing and the stator. The stator’s counterpart is the rotor, which takes care of the rotating part of the mechanical seal.
Stator with rubber cup or profile ring
Stators are available with an O-ring as the seal in various materials, but also with a rubber cup or a rubber profile ring. These models are also known as cup seats.
Stator with anti-rotation pin
In many pumps, an anti-rotation pin is fitted in the pump chamber to stop the stator from turning in the pump housing. With crystallising products, you often see the seal faces of the mechanical seal stick (or bond) together because of the product. The sugars in the product make the seal faces stick together like glue, and during start-up this can cause the rotor to drag the stator round in the pump housing. The stator then turns in the pump housing, while its O-ring is a static seal, not a dynamic one. It will fail within seconds. The anti-rotation pin locks the stator by means of a notch on its back, so it cannot turn.
Does your stator crack or break at the notch?
When the stator is made entirely of silicon carbide (SIC), carbon (CAR) or ceramic (CER), we call it a monolithic stator. The drawback is that the CAR, CER or SIC quickly cracks at the notch when it is dragged round at the point where the anti-rotation pin touches it. Qseals supplies the stator in stainless steel (RVS316) with a SIC or CAR insert, or in solid tungsten carbide (TC). This gives your application a longer service life.
Available materials:
Ceramic
SIC (silicon carbide)
TC (tungsten carbide, also abbreviated as WC)
Carbon (graphite)
Chromium oxide (CR203)
RVS304 (stainless steel)
RVS316 (stainless steel)
With various elastomers, including:
NBR (nitrile)
EPDM
Viton (FKM, FPM)
FEP/Viton and FEP/silicone
QK
Kalrez (FFKM)
Other material options are available. Ask us via the contact form.
Qseals stators
Qseals stationary seats are designed for maximum interchangeability, so you can use them with as many rotating seals as possible. To make sure your seal faces match correctly, contact us to check compatibility for rotating and stationary combinations that are not listed. Qseals stationary seats fit DIN housing dimensions.
