The Type ***4 high-temperature, high-performance Type C, Arrangement 1, API **2/ISO ****9 qualified cartridge seal is designed for high-temperature applications such as hot hydrocarbons and crude oil fractionation products. The Type ***4 utilizes a stationary Inconel **8 welded metal bellows with flexible carbon graphite secondary seals. The stationary mounted metal bellows seal is able to handle higher shaft speeds. The Type ***4 utilizes a segmented spring-loaded carbon throttle bushing for effective containment and can come equipped with a retained mating ring for vacuum service. The Type ***4 is often supported by an API Plan *2 quench (steam) and a steam guide for effectively routing of the steam to the seal faces to help eliminate any coke build-up that could occur when sealing hot hydrocarbons.