As an engineer, I know that small things can have a big impact on how well my designs work.
The back check mechanism in hydraulic door closers is a detail that is often overlooked but can have a big effect on how well doors work in buildings.
Have you ever had a door close on its own, hurting you or causing damage? Or have you ever found it hard to keep a door open when it was windy? These are just some of the problems that can be stopped by using back check.
In this article, I will talk about what back check is, how it works, and why it is important for engineers to know about it and take it into account when building structures.
So, whether you are a student or an experienced engineer, come with us as I explore the world of back check in hydraulic door closers.
Introduction to Back Check in Hydraulic Door Closers
Formal definition:
In a hydraulic door closer, a mechanism slows the speed with which a door may be opened.
Back check is a feature that can be added to hydraulic door closers.
It slows the door's opening motion so it does not slam into the wall or other objects.
The Purpose of Back Check
The point of back check is to soften the way a door swings open and keep it from slamming too hard into the stop.
It is made to slow down the door's opening swing by a certain amount and control the door's speed as it opens.
Back check controls the flow of hydraulic fluid by narrowing or widening its path.
This keeps the door from slamming open and damaging the door, its frame, and its hardware.
Back check keeps the door from getting damaged and keeps people who may be standing behind the door from getting hurt.
On a windy day, for example, when an outside door is opened, the wind may push it open further than intended.
Back check will stop it from flying open and hurting someone.
Using Back Check
Back check is not meant to be used as an artificial door stop.
It is one of the four control zones in a door closer, and doors should not be stopped there.
To adjust the back check, close all three hydraulic valves and turn the door 1.25 to 1.5 clockwise counterclockwise before opening it.
This will make sure the door stops hard and steady at about 75 degrees.
Back check and an extra stop should be used together to make sure that doors do not open too far and damage nearby walls or hardware.
Introducing Back Check: Adding a Slow and Frustrating Touch to Your Doors
Still hard to understand? Let me change the point of view a bit:
Are you tired of how quickly and easily your doors open? Do you wish that getting into or out of a building was more difficult and took more time? Well, do not worry, because we are going to talk about back check in hydraulic door closers today.
This is the perfect solution for people who can not get enough of slow, heavy doors.
Yes, that is right.
Why bother with smooth, easy entry and exit when you can waste precious minutes of your day fighting with a door that will not stay open or closes too quickly? Back check is a great way to make your daily life more annoying.
Okay, that was just a joke made to look like a TV ad.
Now, let us get back to the explanation.
Benefits of Hydraulic Door Closers with Back Check
Hydraulic door closers with back checks are important parts of commercial doors' hardware because they make the doors safer and easier to use.
Benefits of Hydraulic Door Closers with Back Check
Hydraulic door closers with a back check offer a number of advantages, such as:
- To stop doors from slamming, the back check controls the door closer's opening speed during the last 20 degrees before the door is fully open.
The back check feature slows the door down and keeps it from opening too quickly and breaking things or hurting people behind it.
This feature is also good for accessibility because it keeps doors from slamming.
- Safety: Back check keeps people from getting hurt and makes doors easier to open.
It softens the door's opening swing and keeps it from stopping with too much force.
Hydraulic door closers with a back check are often used in commercial buildings like hotels, office buildings, hospitals, schools, and public buildings.
Applications of Hydraulic Door Closers with Back Check
Hydraulic door closers that have a back check can be used for a wide range of business tasks.
They are usually put on doors that go outside, doors that go inside, and fire doors.
Hydraulic Valve Controls
In a hydraulic door closer, the controls on the hydraulic valves control four areas: the back check, the main speed, the speed at which the door latches, and the delay.
When a hydraulic door closer is turned on, the back check is the first control that is used.
As back check does not replace it, there should be an extra stop.
Advanced variable back check options provide cushioning earlier in the opening cycle for applications that are very rough on the system.
Adjustment of Floor Closers
Floor closers can be adjusted in the same ways as other hydraulic closers.
These are swing speed, closing speed, and back check.
Back Check Mechanisms in Door Closers
The Function of Back Check in Door Closers
Back check is a feature of hydraulic door closers that controls how fast the door opens during the opening cycle.
It slows the door down to a certain point so that it does not fly open and cause damage.
It is a part of a door closer's closing cycle that slows the door down before it hits a door stop or the fully open position.
Back check keeps the door, its frame, and the walls from getting damaged if someone opens it by throwing it or crashing through it.
Delayed Action in Door Closers
Door closers also have a feature called "delayed action." This lets the door stay open for a certain amount of time before the closing cycle starts.
Delaying action can be helpful in some situations, like for people who can not move quickly or in places where carts or wheelchairs need more time to get through.
Most of the time, delayed action is not used on fire-rated doors or emergency exits because it can make it harder to get out in an emergency.
Types of Door Closers
Hydraulic or electric motors can be used to close doors.
Most standard hydraulic closers have three hydraulic valves that can be adjusted: the main speed, the latch speed, and the back check.
These valves work together to help the door close smoothly.
Depending on the type of closer, there may be more valves like a closing valve, a valve with a delayed action, etc.
Factors to Consider When Selecting a Hydraulic Door Closer with Back Check
When choosing a hydraulic door closer with back check, it is important to think about where the door is.
Exterior doors need to be checked from the back so that the door, its frame, or the walls do not get damaged.
Back checks are also done on doors that could swing into nearby walls or furniture.
Another thing to think about is the type of locking device that will be used.
Some hydraulic door closers have locks built in, while others need locks that are bought separately.
Another thing to think about is what kind of weather seals will be put on the door.
Weather seals help keep wind, water, and noise out.
Size, mounting, use, and appearance are also things to think about.
There are different spring sizes to fit doors of different sizes and weights and different constructions to meet architectural, institutional, or security needs.
Adjusting the Back Check Mechanism in a Hydraulic Door Closer
Find the backcheck valve to change the speed and force of a hydraulic door closer's back check.
The backcheck valve controls how fast the door opens in the last 15 to 20 degrees before it is fully open.
To change how fast the valve opens, turn it clockwise to slow it down or counterclockwise to speed it up.
To adjust a standard hydraulic door closer, turn the three hydraulic valves clockwise until they stop, which will close them.
Then, turn it 1.25 to 1.5 times in the opposite direction and open the door to make sure it stops hard and steady.
At about 75 degrees, the door should start to slow down so it does not hit the wall behind it or get caught in the wind.
If you turn any of these valves clockwise, the speed goes down, and if you turn them counterclockwise, the speed goes up.
When you turn any of these valves, it does not take much to change how the door closer works.
Start with no more than an eighth of a turn and test your changes by opening and closing the door several times.
Adjusting and Disabling Back Check in Door Closers
When choosing a hydraulic door closer with back check, it is important to think about things like where the door is, what kind of locking system it has, what kind of weather seals it has, how big it is, how it will be mounted, what it will be used for, and how it looks.
Backcheck is a feature that can be added to hydraulic door closers.
It keeps the door from opening too quickly and slamming into the wall or other things.
The speed of the door during the rest of its opening cycle is controlled by how much the opening swing is slowed down.
The backcheck speed of a door closer does not need to be changed for ADA compliance.
But state or local building codes may have specific rules about how exterior doors need to be made accessible.
Adjusting Back Check
Find the backcheck valve on a hydraulic door closer in order to change the backcheck.
The backcheck valve controls how fast the door opens in the last 15 to 20 degrees before it is fully open.
To change how fast the valve opens, turn it clockwise to slow it down or counterclockwise to speed it up.
Small changes to how the door closer works can make a big difference.
Start with no more than an eighth of a turn and test your changes by opening and closing the door several times.
Backcheck is a feature that can be turned on or off, but it can not be turned off completely.
Some door closers, on the other hand, may let you set the backcheck to a minimum or turn it off completely.
Before you try to turn off the backcheck function, you should check the manufacturer's instructions.
Other Considerations
When adjusting backcheck, you should think about how the door is used.
For example, the backcheck speed of a door closer in a school or prison should be much slower than that of a door in a chiropractor's office.
Also, the speed at which the door closes or swings must not be faster than five seconds for it to be ADA-compliant.
From when the door is open at 90 degrees to when it is closed at 12 degrees from the latch, this is called the swing distance.
The speed of the latch should be fast enough to close the door, but not fast enough to slam it.
Use cases
| Used in: | Description: |
|---|---|
| Safety in Public Buildings | Safety is the most important thing in public buildings like schools, hospitals, and office buildings. Hydraulic door closers that have a "back check" feature can help keep doors from slamming shut and hurting or damaging people or things. For instance, kids often run through doors at school, which can cause them to slam and hurt someone. With back check, the door will slow down before it closes, keeping people from getting hurt or causing damage. |
| Resistance to the weather | When there is a lot of wind, doors can open and close quickly, making noise and possibly putting people in danger. Hydraulic door closers with a back check can help stop this from happening by controlling the door's speed and keeping it from opening or closing too quickly. This can also save energy by making it harder for air to get in and out of the building. |
| Accessibility | Opening doors can be hard for people who are disabled or have trouble moving around. Hydraulic door closers that have a back check can give people more time to get in or out of a building. This can help people with crutches, walkers, or wheelchairs get through the door without feeling rushed or pressured. |
| Protection from fire | Hydraulic door closers with back checks can help stop fires from spreading in buildings with fire protection systems by making sure doors are closed and sealed. When a fire alarm goes off, the doors can close and lock on their own, stopping smoke and flames from spreading. This is especially important in buildings with more than one floor or in open areas where fire can spread quickly. |
| Energy savings | Hydraulic door closers with a back check can help reduce heating and cooling costs in buildings where energy efficiency is a concern by stopping air from getting in. When doors are shut too quickly, they can make a difference in pressure that lets air get in or out of the building. Back check can help stop this problem and save money on energy costs by letting you control how fast the door moves. |
Conclusion
As we wrap up our discussion of back check in hydraulic door closers, it is clear that this small but important part has a big impact on the safety, efficiency, and overall functionality of doors in buildings.
By thinking about the benefits and uses of hydraulic door closers with back check, understanding the differences between back check and other door closer mechanisms, and choosing the right door closer for your design, you can help prevent potential hazards and improve the user experience.
As engineers, it is important to remember that even small things like back check can have a big effect on how well our designs work.
By looking at engineering solutions as a whole, we can make places that are safer, more efficient, and more comfortable for everyone.
So, the next time you design a building, do not forget to choose door closers with back checks.
By doing this, you will help make the built environment safer and more stable for everyone.
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