In what situations is mechanical seal injection flushing used?
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For internal single-face seals, when the medium to be sealed is not suitable as a sealing fluid – such as when it contains solid particles (e.g., in slurry pumps used in refinery catalytic cracking units) or when it has high temperature and high viscosity (e.g., in bottom pump units in refinery atmospheric and vacuum distillation units) – it is necessary to introduce a sealing fluid from the outside (wax oil and diesel fractions are commonly used in refineries), which is then injected into the sealing chamber to improve the conditions under which the seal operates. Injective flushing can be used for high-temperature pumps with single-end face seals, as well as for pumps handling crystalline substances or solid particles and corrosive media. Injective flushing is sometimes abbreviated as “flushing”.
Injection flushing is typically used in situations where the medium is not suitable for use as a sealant directly. For example, when the medium contains solid particles, the temperature is too high, or the viscosity is high, these conditions can lead to seal damage or poor sealing performance. In such cases, a suitable sealing fluid, such as paraffin oil or diesel distillate, can be introduced from the outside and injected into the sealing chamber to improve operating conditions and enhance sealing reliability. Common applications include pumps used in refineries to handle high-temperature, crystalline, or corrosive media containing solid particles. .