The selection of roller series:
  Option for roller should be based on window&door sash weight, aluminum profile installation space and roller’s maximum load. Window/door sash weight=(Glass weight + sash profile weight)*1.3(safety index). Ensure fixing space between the sash and rail, the shape of the bottom slide rail. Select the corresponding roller upon the above details(1) and (2). The maximum load of roller we provided is the number per twain.
  The installation and fastening of roller
  According to the different profile and roller structure, fix the correct connection method. Fix the fastening mode before sash connection and assembly, and then reasonably use screws to fasten upon the actual situation. The roller must be linked closely with the door&window sash bottom without looseness.
  Requirements for profile and roller installation
  Reserve roller adjustment space when installation and guarantee enough amount of overlap A between the sash bottom and slide rail to prevent sash from running off the rail, especially the umbel rail slipping. Keep the rollers staying at the middle of the bottom rail when installing and make sure the two rollers are on the same line.
  Maintenance of roller
  The routine inspection and maintenance are essential for the rollers to avoid the sand, cement, lime etc some hard raffle and acid-base property corrosive which may cause the sash unsmooth opening and have an bad effect on the rollers.