Door closer products must meet the national standard GB2698-2005, fire door closer  should also meet the requirements of GA93-1995 “Door closer test for fire doors”. 
The factors that should be considered when choosing a door closer are: the width of the door, the frequency of opening the door, the use requirements and the use environment, etc. The width of the door is the most important factor in choosing the door closer model. Common doors include fire doors, wooden doors, aluminum alloy doors, glass doors, and steel doors. Usually the weight of the door is small, so choose the model with less power, and vice versa. The door opening frequency is a factor closely related to product quality. For frequent use occasions, the product should be required to have good sealing performance and long life.
1) Whether it is necessary to automatically stop the door after opening the door;
2) Damping buffer function-the damping buffer is generated after the door is opened quickly to a certain position, and the damping buffer force and range can be adjusted according to the use requirements; this function is used to prevent the door or lock from hitting the wall when the door is opened quickly, or emergency escape Time to prevent people from leaning forward and falling to the ground due to weightlessness when opening the door quickly.
3) Delayed slow door closing-the door closes slowly at a uniform speed from the maximum position of the door opening, and can be adjusted steplessly according to requirements. It is suitable for use in places with frequent entry and exit, especially in hospitals, where there are doors and passages for the elderly, children and the disabled to enter and exit.
4) The closing force can be adjusted-it can be used for installation on doors with a wide range of door weight and door width, and in places where the door closing resistance is large due to environmental reasons. Stepless adjustment at will to obtain a satisfactory closing force, especially in seaside cities, vehicles and ships, where the closing resistance (the force on the door) often changes due to the influence of wind.
5) Temporary closing performance of damping reset function (vertical door closer)-when opening at any angle, closing the speed control valve should temporarily suspend the damping reset function.
6) Safe and fast super damping closing performance (vertical door closer)-It should be able to close safely and quickly when an external force is suddenly applied during closing at any angle.
7) Operating environment: fire-fighting requirements and anti-freezing requirements for places below minus 35° in winter.