Change-out of Internals
There are two internal components within an SJP, namely the HP nozzle, and diffuser or mixing tube unit. The internal geometry of these two items is what gives the SJP its operating characteristics. Change-out of the internals is only required if there is a significant change to one or more key operating parameters. As the nozzle and diffuser are matched to each other, it is usual to change-out both internals together, unless the change is primarily related to the HP flow. Changing the internals is relatively simple and can be carried out within a few hours; the time needed includes full isolation of the system, venting and draining before the SJP can be opened. Detailed procedures related to SJP internals change-out are available for this operation.