Suggested translation:
“油封膜连续、均匀、不流淌、无杂质、长时间存放无明显沉积，”--> the sealing oil film should be continuous, uniform, free of drips, free of impurities, and free of obvious deposits upon prolonged storage,

Oil sealing (i.e., oil coating) is similar to painting. Here is an example in painting:
http://www.ezpaintinginc.com/
“A properly painted surface is one that is uniform in color and sheen. It is one that is free of foreign material, lumps, skins, sags, misses, strike-through or insufficient coverage. It is a surface free of drips, spatters, and spills or over spray.”