The newly installed door closer should be inspected and re-tightened for about a week to 10 days.

    The hydraulic oil recommended by the manufacturer should be used in cold areas with low pour point.

    After the door closer is put into use, it should be checked regularly. The contents of checking are: whether the installation screw is loose and lost, whether the connecting arm rubs against the door body or the door frame, whether the door body is deformed and loosened, the cushioning effect of the door closing, whether the supporting guide is leaking, etc.

    The following problems usually arise after the door closer is used for a period of time:

    1) Installation screw loosened or lost, resulting in the closer not in the correct installation position, connection arm damage;

    2) When the door closer closes, the cushioning effect becomes worse, which results in the impact between the door and the door frame and the deformation of the door body.

    From the point of view of structure, the door closer is a closed whole, and its quality can not be seen from its appearance.

    The key quality problem of the door closer is whether it leaks oil, because the door closer relies on the throttling of fluid in its internal hydraulic system to control the closing process. Oil leakage means the failure of the hydraulic system, so the hydraulic system is the only standard to determine the service life of the door closer.

    The main reason for oil leakage is that the wear of pinion bearing guide parts increases the clearance, the wear of sealing ring causes the sealing effect to decline, or the throttle spool rotates counterclockwise away from the valve body when adjusting the cushioning effect.

    The reduction of the buffer effect of the shutter is due to the air entry caused by oil leakage or the increase of the clearance between the rack plunger guide cylinder and the valve body. Therefore, the quality and accuracy of pinion, supporting guide parts, heat treatment and machining are very important.

    For the door closer with poor cushioning effect, throttling by adjusting the throttle valve spool alone can not fundamentally solve the problem. It must be maintained. If the oil leaks from the supporting guide, remove the supporting guide and check the condition of the sealing ring. If it is worn or aging, replace the sealing ring. If the clearance between the supporting guide and the pinion shaft is too large, replace the supporting guide. If the rack plunger guide cylinder is worn and the clearance between the rack plunger and the valve body increases, the throttling effect decreases. The rack plunger can be removed and repaired by chromium plating on the surface. In addition, under the condition of ensuring the cushioning effect of the door closer, the use of a softer spring is also a way to reduce the impact force of the door on the door frame due to the poor cushioning effect.