hydraulic pipe joints completely or partially blocked by the following reasons

hydraulic pipe joints completely or partially blocked by the following reasons:
① no good filtration mobility ; ② samples for particulate ; ③ pump or injector gasket debris ; ④ pre-column , bollards and analysis column leaking stuffing ; ⑤ burrs and filings entered ;Hydraulic ferrules ⑥ mobile phase crystallization salt ; ⑦ ⑧ microorganisms into the system of other particulate substances