While tanks rolling on rotator , the tanks often move on rollers . How to prevent traverse ? We may lift roller and change workpiece's weight center,   We ortern use hydraulic push / pull as the photos, this type is  simple and save money.

     Another thing, While we connect 2 tank and want to get a good joint , We often lift up one tank, may link to another tank, and then weld a spot .

     Up/down Stroke Distance : 200 mm (Design according to working site)

     Up/down type: Hydraulic control