Flushing, external flushing, infeed, injection; installation in conformance with DIN ISO 5199, Appendix E, Plan No. 08a or API 610, Appendix D, Plan 32. Flushing entails feeding a clean, mostly cold external medium in the area of the sliding faces into the stuffing box and via a flow rate restrictor (throttle) into the medium to be sealed. Flushing serves either to lower the temperature or prevent deposits in the area of the mechanical seal.