Mechanical end seals, in any configuration, single or double, require appropriate flushing, which is essential to lubricate the seal faces and remove the heat generated due to the friction that occurs between the faces themselves.
For this reason, the correct selection of the mechanical seal must be made according to operating parameters e must include the type of flushing to be applied to the pump or agitator to ensure correct operation.
The API682 standard has defined a nomenclature to identify the flushing types required for each type of application, allowing the selector to indicate the (numeric) code that the customer must apply to the machine for the seal to function correctly.