The key component of the 7500 rotary shaft seal design is the solid elastomer, which is made from FDA approved silicone and can handle temperatures up to 400F degrees. The 7550 model is more suitable most powder applications. The elastomer is molded slightly smaller than the shaft size so that an interference fit is achieved. It is this tight fit that seals the shaft, which stops material from migrating past, and drives the two rotating faces called “rotor cups”. The rotating rotor cups compressed against the two stationary stator plates is what creates the primary seal that stops product leakage. These dynamic seals are also air purged at 5 to 7 PSI above any pressure in the vessel to assist in maintaining a positive seal. The key component of the 7500 rotary shaft seal design is the solid elastomer, which is made from FDA approved silicone and can handle temperatures up to 400F degrees. The 7550 model is more suitable most powder applications. The elastomer is molded slightly smaller than the shaft size so that an interference fit is achieved. It is this tight fit that seals the shaft, which stops material from migrating past, and drives the two rotating faces called “rotor cups”. The rotating rotor cups compressed against the two stationary stator plates is what creates the primary seal that stops product leakage. These dynamic seals are also air purged at 5 to 7 PSI above any pressure in the vessel to assist in maintaining a positive seal.