Newly installed door closers should be inspected and tightened again after one to ten days of use.
Use the hydraulic oil recommended by the manufacturer; in cold regions, use low-pour-point hydraulic oil.
After being put into use, door closers should be inspected regularly. The inspection should include: checking for loose or missing mounting screws; whether the connecting arm is rubbing against the door or door frame; whether the door is deformed or loose; the door's closing cushioning effect; and whether the support guide is leaking oil.
Typically, the following problems may occur after a period of use:
1) Loose or missing mounting screws, resulting in the door closer not being in the correct installation position and damage to the connecting arm;
2) Decreased cushioning effect when the door closer closes, causing impact between the door and door frame, and door deformation.
Structurally, a door closer is a closed unit, and its quality is generally not apparent from its appearance.
The most critical quality issue for door closers is oil leakage. Door closers rely on their internal hydraulic system to throttle fluid flow and control the closing process. Oil leakage indicates hydraulic system failure, making the hydraulic system the sole determinant of a door closer's lifespan.
The primary causes of oil leakage are: increased clearance due to wear on the pinion support guide; reduced sealing effectiveness due to worn seals; or the throttle valve core rotating counter-clockwise away from the valve body when adjusting the buffer effect.
A decrease in the door closer's buffer effect is caused by air entering due to oil leakage or increased clearance (throttling) between the rack plunger guide surface and the valve body. Therefore, the material, heat treatment, and machining quality and precision of the pinion and support guide are crucial.
For door closers with poor buffer effect, simply adjusting the throttle valve core will not fundamentally solve the problem. Repair is necessary. If the leakage is at the support guide, remove the support guide and inspect the seals. If worn or aged, replace the seals. If the clearance between the support guide and the pinion shaft is too large, replace the support guide. If the rack plunger guide surface is worn, increasing the clearance between it and the valve body and reducing the throttling effect, the rack plunger can be removed and repaired by chrome plating. Alternatively, while maintaining the door closer's cushioning effect, using a softer spring is another way to reduce the impact force of the door on the door frame due to a decreased cushioning effect.
