Door closer service and lock service are inter-related. The service life of a lock is directly dependant upon how well the door closer performs. I remember when I got serious about door closers. I was visiting my good friend George Redmond at Redmond’s Key Service. We were about to go to...
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Parallel-mounted is where the closer body is attached to the push side of the door and the closer arm is attached to the push side of the jamb face. At rest, the closer arm is mounted so that it is tucked into the width of the jamb. The closer forearm is “parallel” with the door face.
Concealed closers can be further differentiated by where they are mounted:
Top-mounted is where the closer body is recessed into the header rail of the jamb and the closer arm is attached to the top of the door.
Floor-mounted is where the closer body is recessed into the door threshold and the arm is attached to the bottom of the door.
Notice the relationship of the closer arm to the closer body in Figure1, Figure 2, and Figure 3. In Figure 1 and Figure 2, the closer arm rod is perpendicular to the face of the door. In Figure 3, the closer forearm is parallel to the door.
It is essential that these relationships be respected. Failure to respect these relationships will cause: failures to one or more of the door controls, rough door operations or an unpredictable maximum door opening.
Once you have committed to memory how the closer arms should look, it will be easy to spot a closer out of adjustment due to the relationship of the closer arm to the closer body.
In Figure 4, it is easy to spot closer arms that are either installed incorrectly or the arms are out of adjustment.
Surface-mounted closers are easier to work on as all the components are readily available and the door does not have to be pulled. They are easier to install as the door is mounted to the jamb during the install.
Concealed closers require the door to be pulled to work on them. When installed on exterior doors, concealed closers are more vulnerable to weather, as part of the closer is extends to the outside of the building.
Floor closer are especially vulnerable to flooding as water hits the closer directly or is drawn in by osmosis through the exterior concrete.
Closers are not necessarily pretty. For that reason, building architects or the agents of architects often choose concealed closers for aesthetics. Surface-mounted closers with decorative finishes can add to aesthetics.
Without a door closer, a door would be thrown open, either damaging the door, the wall, or a person caught in the swing. A door would slam shut to the point of similar damage.
Proper door control is essential to preventing damage and maintaining life-safety.
Five Stages of
Proper door control is achieved by controlling five stages of door operation (Figure 6):
Opening Arc. As the door is opened, the process must be smooth and easily performed. Doors that must comply with barrier-restrictions must be operable with a prescribed maximum force.
Backcheck. Once the opening swing has been performed, the backcheck offers sufficient resistance the keep the door from abruptly stopping. This “cushions” the stop so that the door or wall is not damaged. Some closers provide a variable backcheck so that if a door is swung open quickly (by the wind for instance), the backcheck is self-adjusts to greater resistance than normal.
Delayed Action. Some doors are required to meet ADA or barrier standards designed to accommodate the passing of wheelchairs or persons with walkers or crutches. These doors will feature a delay action, allowing for a slower passing through of the door.
Closing Arc. The speed of the closing arc can be adjusted from slow to swift. Additional forces like wind or manual pressure are made to be resisted by the door closer.
Latching Arc. A door can be made to close swiftly through the closing arc, then slowly through the latching arc. The latching arc is the last few inches of the closing operation. The latching arc prevents persons from getting their fingers crushed when a door closes to fast.
Door control adjustments are determined by the door service.
If the door serves as a barrier-free entry, the opening arc will be controlled to be easily opened. The delayed action will be tuned to provide a slow swing for about 75 degrees, then a normal speed will continue through the closing arc.
If a door serves as a popular building exit, the delayed action will be turned off and the closing arc will be tuned to provide a swift closing.
The LCN 4040XP is the second generation heavy duty door closer designed to withstand even more rigorous applications.
Corbin Russwin DC6000 Series door closers incorporate new features.
For any door closer to be effective, the door and frame must be fully functional.