Langir: Your Reputable Emergency Stop Push Button Supplier from China

Langir is your number #1 choice of emergency stop push button supplier from China.

We provide our customers world class quality emergency stop push buttons and are committed to ensuring the safety of our customers too.

Our emergency stop push buttons are particularly developed not only to be tough but also to be highly dependable each time an emergency occurs.

Aside from just stopping a machine, you can also use our emergency stop push button on a bus or a train to signal a stop to the driver.

Langir’s emergency stop push buttons are compliant with safety standards that are important for you, our customers.

We always prioritize your safety so that you can be worry-free and can focus on other things that are important to you.

Langir’s emergency stop push buttons undergo strict quality inspections and certifications to ensure that we meet your expectations and protect your safety at the same time.

When you order with us, your emergency stop push button order will immediately leave our facility and will be delivered straight to your doorstep in a few days.

Our friendly operators are always on standby to answer all your inquiries and take your orders all the time.

You can also request a free quote now or send your inquiry and receive our response right away.

Emergency Stop Push Button – FAQ Guide

In this emergency stop push button FAQ guide, you will learn various things about the emergency stop push button.

You will learn its detailed definition, its history, different applications, types, and other things that you don’t about the emergency stop push button until after reading this guide.

Furthermore, you will also learn interesting things about the emergency stop push button like why it is bright red and not other colors or why it has a mushroom head type in the first place.

So before you go ahead and purchase, read this guide to gain better knowledge and pick out the best emergency stop push button for your application.

1. What is an emergency stop push button?

Different types of the emergency stop push button

An emergency stop push button is a safety mechanism, device, or switch that is used to manually turn off or shut down a machine in times of an emergency or when the machine can’t be shut down in a normal manner for some reason.

For instance, a machine emergency stop button.

It is also used for vehicles and transportation to signal a stop to the driver or lay down emergency breaks.

The term emergency is derived from the word “emergent” which means a situation that is about to happen or developing at the moment.

The emergency stop push button is made with this intention, to stop a potentially harmful accident to happen.

An emergency stop push button is also called a kill switch, e-stop, E stop switch, emergency switch, emergency button, emergency stop, emergency stop button, stop emergency, switch emergency stop, emergency stop switch, stop switch, button emergency stop, emergency stopper, emergency stop pushbutton, emergency stop button switch, double pole emergency stop button, or emergency stop push button switch.

Unlike when you normally turn off a machine where it sequentially and safely shuts down all of its systems and operation in the usual manner, the emergency stop push button shuts them all down immediately and sometimes to the point that it can sometimes cause damage to the machine.

The emergency stop push button is designed to abort the operation as soon as possible with just a push of a button that even a panicking operator or even any untrained personnel can execute easily when the emergency arises.

Fun Fact: The emergency stop push button is not a safeguarding device

The emergency stop push button is considered a safety device since the early times, however, the ISO and IEC international standards clarify they are technically not.

They clarified that the main intention of the emergency stop push button is to stop existing damage to a machine or a person and it should be initiated with a single human action.

The notion of a safeguarding device would mean that if danger is about to happen, the machine will automatically stop which the emergency stop push button is not.

Since it is a mechanical device, it needs a manual physical intervention therefore someone needs to press it so it can be activated.

You can also see it this way, the safeguarding device is proactive, while the emergency stop push button is reactive.

An example of emergency stop push button

2. What is the history behind the development of the emergency stop push button?

During the era of the industrial revolution, between the 1820s up to 1870s, the power supply of the types of machinery is coming from large central power sources such as steam engines, water wheels, and large electric motors that also supply the power to the whole factory or factories.

Therefore, stopping a machine when something went wrong means stopping the power supply of the whole factory as well.

The machine builders realize this problem and decided to find a way to quickly stop the machine operation when needed.

One of the early inventions of a stop device is the belt shifting device which has a drive belt that can be shifted from the idle state to the driving state then reverse state to stop the machine.

The emergency stop push button was developed from these origins.

Belt shifting device illustration

3. Why is it cheaper and safer to have an emergency stop push button?

In the 1900s, many industrial accidents resulted in financial loss, caused human injuries, and even claimed the lives of thousands in the US alone.

A study published in 1916, stated that industries, in general, suffered a financial loss amounting to $500 million, serious human injuries and dismemberments averaging about 350,000, and minor accidents which caused loss of time costing more than $2 million on a year to year basis.

Basing on these numbers, you can conclude that it is perhaps cheaper to add an emergency stop push button to the machines compared to the amount spent for the hospitalization of the injured personnel and other costs.

The emergency stop switch price or emergency stop button price nowadays is anywhere between $7 up to $20.

But unfortunately, the industry sectors during those times prefer to prioritize the economical aspect of the business with less focus on the safety of their people.

And because of this, it always takes years of more human casualties and outbursts of strong public opinion before safety standards and government legislation are implemented.

This has become a cycle over the years and lawmakers always wait until public indignation is happening before taking action.

But eventually, the growing government intrusion is becoming a problem with the industrial sector.

Because of this, the industries formed committees and organizations intending to propose safety standards voluntarily.

Then in 1969, the American National Standards Institute, or ANSI, developed the safety code standards applicable to different industrial operations.

However, most of these standards do not provide specific information about the emergency stop push button and other emergency stop devices as they are always written in performance styled language.

This allows the manufacturers to develop their own emergency stop devices but it became a problem for machine operators who will work in a different factory or will be assigned to a different brand of machine which would have a different design and controls.

This is because the emergency stop devices between different types of machines are most likely different from each other which can cause confusion to the operator and will cause a delay in stopping the machine if an emergency takes place.

This is one of the reasons ANSI developing consensus standards about emergency stop push buttons when it comes to its type, design, or its placement on the machine in the succeeding years.

There were many revisions and clarifications on these consensuses on safety standards over the years but these are the guidelines that helped paved the way for emergency stop switch suppliers to develop the emergency stop push button that we know today.

An old emergency stop push button in a factory

4. How does the emergency stop push button mechanism work?

The emergency stop push button is a critical operating component acting as a fail-safe control switch that generally provides safety to the operator and the machine in various emergencies.

An emergency stop push button is generally wired in series within a machine’s control circuit.

If you press the emergency stop push button, it instantly breaks or cuts the circuit and stops the power supply that runs the machine, and immediately shuts the machine down during an emergency.

In instances that the emergency stop push button needs to be released, it sometimes requires an authorized operation that requires pulling, rotating, or even using a key to make sure the safety of the people and machinery and prevent any accidents to occur.

Disassembled parts of the emergency stop push button

5. Is the emergency stop push button NC or NO contact?

Depending on its specific function or application, the emergency stop push button can be normally closed or normally open contact.

But some operators prefer NC or normally closed emergency stop push button and there are a few notable reasons why.

And these are because of the following:

• Shorter operating time

The time that normally closed contact takes from closing to opening is shorter when compared to the time that normally open contact takes from opening to closing.

It may come as a surprise to you, but this is true and the shorter time matter especially during an emergency.

Every second counts, even milliseconds, when there’s an emergency especially when the machine operator is at risk of getting injured, or moreover when lives could be in danger.

Accidents can happen in just seconds, having a normally open contact for an emergency stop push button or normally open emergency stop button may not be the safest choice.

In a split second, it may not be able to stop a machine from causing personnel injury or from damaging the machine itself when its operation goes wrong for some reason.

While having an NC emergency stop push button may save a second from stopping a machine and avoiding all of that to happen.

• Button mechanism perspective

All mechanical push button when pressed, further down to the end, they will bounce back which means that it was not actuated.

If the emergency stop push button is a normally open contact, when it is not pressed, the emergency stop is not in effect because the contacts are open and not closed.

While if the emergency stop push button is a normally closed contact when it is not pressed, the emergency stop is in effect because the contacts are closed.

• Control circuit perspective

An emergency stop push button’s most basic function is to stop any untoward accident to happen to the machine’s operator and the machine itself in the instant that an emergency happens.

If the emergency stop push button is NO contact, there’s a tendency that you will encounter a fault because something went wrong in the control circuit or there’s a fault on the emergency stop part in the control circuit line.

The damage caused to the machine could be irreparable and in a worst case scenario, an accident has already happened.

Unlike if the emergency stop push button is NC contact, usually, even when the emergency stop component encountered a fault, the machine will stop.

The machine damage is relatively small and accidents are highly likely prevented.

A conveyor machine operator

6. Is the emergency stop push button a latching or momentary type?

The emergency stop push buttons are latching type or momentary type of switches.

It depends on what application you will use it for.

• Latching emergency stop push button

The latching emergency stop push button is primarily used for stopping a machine operation.

It is sometimes called lockable emergency stop button or latching emergency stop switch.

Machine operations require thorough inspection before resuming its operation to ensure that no further damage will happen or machine issues have been resolved or fixed.

The same safety measure is applicable if the emergency stop push button is used on other applications aside from machine operations.

• Momentary emergency stop push button

The momentary emergency stop push buttons are generally used on applications that do not require the latching switch function.

Usually, in these applications resuming the task of the machine is assigned to a different control or switch or the machine is generally safe to restart after suddenly stopping it.

7. How many types of emergency stop push buttons are there?

There are 3 most common emergency stop push buttons available and they are:

• Push-pull emergency stop push button – The push pull emergency stop button is pressed to stop and it requires to be pulled to be released to place the button back to its normal position.
• Twist release emergency stop push button – The button is pressed to stop as well, but it needs to be twisted to be released and place the button back to its normal position.
• Key release emergency stop push button – The button is pressed to stop and can only be released and placed back to its normal position using a key.

For example, emergency stop push button with key, emergency stop button with key, emergency stop switch with key, emergency stop with key

The other types of the emergency stop push button are:

• Foot and palm emergency stop push buttons

They usually have a large actuator surface that can be actuated by using your foot or hand.

Because of the manner of actuation, they are generally tamper-proof and designed to make a quick response.

These types are ideal for harsh environments.

• Position switch

These switches are linked or connected to an emergency stop actuating component.

They are highly reliable as well and usually easy to fit.

Twist release emergency stop push button

8. In what applications are the emergency stop push button is used?

Since the emergency stop push button promotes safety, it can be found in many types of equipment, machines, or emergency systems in various industries.

Some of the applications where the emergency stop push button is used are:

• Machines
• Trains and railways
• Boats
• Ships
• Trucks
• Fuel stations
• Road vehicles
• Elevators
• Escalators
• Gym
• Amusement rides
• Mechanism with incorporated software
• Power plants
• Military
• Aircrafts
• Space shuttles

Emergency stop push buttons are present in various industries like industrial, commercial, and public facilities.

They are necessary to be clearly noticeable to anyone that is required to use them.

A machine can also have several emergency stop push buttons if it has several functions depending on which phase has to be stopped.

Applications of the emergency stop push button

9. Is it required to have an emergency stop push button on every machine?

Every machine may or may not require an emergency stop push button depending on where you are located.

Different countries have their own standards and regulations when making machines.

These machines pass through a series of risk assessments to determine whether an emergency stop push button is required.

Usually, these risk assessments are based on the hazard level of the machine or its operation especially to the operator or the people who will work with the machine.

Then the manufacturers of these machines also need to ensure that they comply with the ISO/IEC 38500, a set of guidelines aimed to assist the highest level of organizations to understand and comply with the ethical, legal, and regulatory obligations with the use of IT in their organization.

The (ISO) International Organization for Standardization and the (IEC) International Electrotechnical Commission provided these guidelines for effective corporate governance of information technology.

This is also applicable to all sizes of organizations, public and private businesses, government entities, and also non for profit organizations.

Example of compliant emergency stop push button

10. What are some emergency conditions that may require an emergency stop push button?

Sometimes even when a machine is carefully designed to be safe, it is more realistic to assume that there are situations that will arise when machines will require manual actuation of an emergency stop push button.

This assumption is also applicable to machines that are installed properly and receives proper maintenance regularly.

The reason behind this assumption is that many types of emergencies can happen.

It could be due to electrical, mechanical, environmental, and human errors or can be a combination of any of these.

Moreover, machines generally fail safely at all times even the most dependable ones will fail eventually because there is no guarantee that the failure will not result in damaged parts or components which can affect the overall operation of the machine or cause other components to fail as well.

A machine can have a short circuit that can place harmful powerful voltage on its parts or can run abnormally due to a stuck relay contact, or its parts could jam because of a broken ejection solenoid.

Always check the voltage rating such as 240v emergency stop switch, 120v emergency stop button, 12 volt emergency stop button, 12v emergency stop button, 20 amp emergency stop button, and 30 amp emergency stop button.

These are just some of the most common machine malfunctions in industrial settings.

Below enlists some of the emergency conditions which could require the emergency stop push button:

• A misaligned or defective stock
• A runaway power supply
• An operator entangled in the machine
• An unnecessary substance or part in the feed
• Broken machine tools
• Dangerous chemical spillage
• Electrical explosion
• Feed with blockage
• Fire outbreak
• Jammed machine parts
• Loosened parts
• Machine imbalance

Other emergencies may not be included in this list but the message is clear.

Regardless of how modern or automatic controls are integrated into the machine, the emergency stop push button is still necessary and it should be explosion proof emergency stop button if possible.

The emergency stop push button is an important part of the operator’s function as well.

There should also be contingency plans for the implementation of the emergency stop push button included in the machine design and operator training to make sure that it will be used efficiently when an actual accident occurs.

Trained lathe machine operator

11. Why does an emergency stop push button have a mushroom head?

The emergency stop push button is required to have a mushroom head according to the industry safety requirements and the IEC standards.

This ensures that the emergency stop push button is convenient, safe, and reliable for you to operate by one hand.

The mushroom head is a unique design that is universally known as an emergency stop push button.

It is largely predominant in North America while the cone shape is largely used in Europe.

The mushroom head usually has a smooth surface that will not harm you when you press it even by a sudden force.

Mushroom head emergency stop push button

12. Why does the emergency stop push button have a bright red and yellow background color?

The emergency stop push buttons always have a red button and a yellow background color whether for its base or label plate (i.e. push emergency button, emergency off, emergency power off, emergency push) which sets it apart from all other general switches.

This complies with the following international standards:

• ISO 13850
• IEC 60947-5 (Switchgear and control gear)
• IEC 60204-1 (Electrical equipment on machines)
• NFPA 79 (National Electric Code section on electrical wiring standards in industrial machinery)

These standards require that the emergency stop push button should have a bright red button and yellow background.

Color coding is always a critical factor in proper discrimination of controls and red is the color symbolizing danger or stop which has been used in many centuries until today.

The color red is also a dominant color superior to other colors even from a distance even when with low illumination.

The red color is also more visually identifiable combined with a yellow colored background and because of this; it effectively reduces the search time.

This color combination is eye-catching and makes it easier for anyone to recognize the red emergency stop button even if it is a small emergency stop button against all the other colors of the machine, the entire control system, or its surroundings.

There are even illuminated emergency stop push button so that you can easily them even in the dark.

The other types are made from luminescent materials making them glow in the darkness while others have a focused emergency light solely for lighting the location of the emergency stop push button.

Illuminated emergency stop push button

13. What are the general ANSI useful recommendations for the emergency stop push button?

ANSI has developed different consensus on safety standards for each type of industry.

However, the following are some of the general useful recommendations for the emergency stop push button use:

• A master stop button or control must be mounted in the same place on each control panel like an emergency stop button panel mount.
• The red colored control should be always used in conjunction with an emergency stop push button and other controls must not be red in color.
• The momentary actuation of the emergency stop push button should immediately stop hazardous motion and keep the machine in a safe condition.
• There should be a separate or specific operation when restarting machinery.
• The emergency stop push button should be available to all operators, in each operator’s station, or in the hazardous places where operators are designated to work.
• An emergency stop push button is recommended to be available for every operator on their respective work stations, and in each unsafe location where they are mandated to work.
• A braking system should be integrated into the machine if its parts can coast after the emergency stop push button has been actuated.
• The emergency stop push button should be standardized on similar machines which include its configuration, location on the machine, function, and color coding.
• The emergency stop push button must be tested regularly during routine maintenance to ensure that it is working properly.
• All emergency stop push buttons should be size and shape coded, labeled, and not recessed.

ANSI logo

14. What is the standard usage of the emergency stop push button?

The emergency stop push button also needs to follow a usage standard according to ISO 13850.

Under this standard, the emergency stop push button must be actuated or started by a single human action if a machine can’t be stopped normally or the machine’s normal stopping function has malfunctioned, is not operational, inaccessible, or slow for use during an emergency.

The list below is some of the requirements are stated in the ISO 13850 or the European Standard EN 418:

• A direct opening mechanism is required to be installed on the NC contact.
• A self-holding function is present.
• The actuators should have a mushroom head design or something equal.
• The button must have a red button and a yellow background.

And aside from the requirements listed above, there must be countermeasures for each.

15. Can you avoid an accidental pressing or resetting of an emergency stop push button?

Yes, there are features, safety accessories, and safety measures set in place to prevent the accidental triggering of an emergency stop push button.

• Lock feature

An emergency stop push button can have a lock feature that allows it to be padlocked to prevent any unauthorized personnel from accidentally resetting it and restarting the machine by mistake.

It will require keys for someone to unlock the padlocks and reset the emergency stop push button, and these keys are usually kept secured and only the authorized or trained personnel has them in possession.

The padlocks can be several and will require the same number of keys assigned to each padlock depending on how risky the machine operation is or depending on the owner of the machine.

• Molly-guard

This shields the emergency stop push button from getting accidentally actuated.

Generally, they are made from plexiglass material that acts as a physical barrier for the emergency stop push button.

It needs to be lifted to access the emergency stop push button inside it.

• Break glass

This is similar to fire alarms where the button is secured inside an enclosure with a glass cover and an attached small hammer.

In case of an emergency, you can take the hammer and use it to break the glass so you can press the emergency stop push button.

If you need any of this protection, look for emergency stop button protective cover, emergency stop push button protective cover, emergency stop button cover, emergency stop cover, emergency stop switch with cover, emergency stop guard, or emergency stop button guard.

Emergency stop push button with molly-guard and break glass covers

16. Is the emergency stop push button easy to clean?

A high quality emergency stop push button is generally made from high quality materials and this includes a dust proof and smooth material for its button.

It is also categorized as an ergonomic smooth button that has natural dirt resistant characteristics.

17. Can you use the emergency stop push button in hazardous locations?

Yes, you can.

There are emergency stop push button types that are classified with a class 1 zone 1 rating which means that they can be used in hazardous environments such as places with oil, gas, petrochemical, and so on.

18. What is the difference between the general purpose push button switch and the emergency stop push button?

The general purpose push button switch is typically used for controls.

For example, for starting a machine or switching machine functions, etc.

While the emergency stop push button is utilized as a safety measure or a stop switch to avoid safety risks or machine damage.

19. What are the common arrangements of the emergency stop push button?

There are common arrangements of the emergency stop push button that you will find available and they are:

• Single button

This is the most common arrangement of the emergency stop push button where it is on its own away from other controls or switches.

It is usually located in areas where it can be easily located and reached during an emergency.

• Dual push button stations

This consists of the start stop emergency stop switch arranged in close proximity to a station.

Because of the placement of the two buttons, there’s a possibility that the operator may inadvertently push the wrong button causing a delay in stopping the machine in an emergency.

For example, emergency stop button box, emergency stop switch box, box emergency stop, emergency and stop button with enclosure.

• Custom control stations

These are usually built by engineers hence they are more complex and have a combination of push buttons, multiple switches, signal lights, etc.

They are generally custom designed by an engineer to assemble a control station using standard parts following the personal specifications of the client or the needs of the factory.

The design of the station panel and the arrangement of the controls still need to comply with the established ergonomic standards and principles otherwise it could be confusing to operate even for a trained machine operator.

For instance, emergency stop station, and emergency stop panel, 3 phase emergency stop push button, and 3 phase emergency stop button.

• Emergency trip-wire

Some machines are big such as those with rolls, conveyors, or calenders and due to their size; it is quite difficult to locate the emergency stop push button if there’s only one installed.

This could result in finding the emergency stop push button too late before causing damage to the machine or personnel injury.

This is why the emergency tripwire is developed where push buttons are separately installed every few feet down the stretch of the machine or a tripwire is connected to a microswitch is also another option.

The recommended locations should be where human entanglement can most likely occur or where it can be easily reached by a human entrapped.

Dual emergency stop push button stations

20. What are the human and machine factors affecting the use of the emergency stop push button?

Sometimes, as humans, we have different abilities to recognize danger, select the course of action, and complete the necessary action which is also known as response speed.

The same with the machines, they are built differently hence they operate differently as well.

A well-built machine can better execute its functions than those poorly built.

Therefore there are human delays and lags which can affect the time that an emergency stop push button is actuated and they are:

• Central processing lags
• Human input and receptor delays
• Movement or action time
• Muscle activation time
• Neural transmission delays
• Display lags
• System or machine dynamics delays

Display lags and system dynamics delays refer to the cause of electrical and mechanical features of the machine’s system design.

While the others on the list refer to human factors causing the delay which are also considered by the manufacturers in the design of the emergency stop push button.

21. Why training is important when using the emergency stop push button?

Machine operators and other personnel should have proper training when using the emergency stop push button.

So that when an emergency occurs and the machine needs to be stopped right away, they know where to locate the emergency stop push button and actuate it immediately.

Nowadays, industrial machines are becoming more complex and controls are not easy to learn.

It is not uncommon to find control panels with arrays of lights, different types of switches, knobs, levers, alarms, and so on.

Without proper training, the operator may not be able to do his or her job properly and know what to do when an emergency suddenly happens.

There’s also a significant difference in emergency recognition and response time if the personnel is well trained compared to untrained personnel during the emergency.

Trained machine operators relatively produce better performance, can respond faster to emergencies, can instinctively locate the emergency stop push button, and actuate it to stop the machine.

This is also supported by industrial engineers recognizing that repetitive practice, which can be considered as training, enables the operator to be familiar with the emergency stop push button actuation and function.

Trained complex machine operator

22. What are the recommendations about the design and placement of the emergency stop push button?

When using the emergency stop push button on any application, there are some recommendations that you can use as a guide so it can be consistent with the established ergonomic principles and human expectations.

• If possible provide noticeable warnings of imminent system failures needing manual emergency stops.
• Practice using the emergency stop push button regularly to master the motion of stopping the machine.
• Supply minimum power as necessary to achieve a desirable result.
• Get the machine inspected to reduce audible vibration.
• Mount the emergency stop push button in an easy locate the position where it is very accessible to be activated.
• If you have multiple equipment or machines, standardize the placement of the emergency stop push button to avoid confusion.
• Choose an emergency stop push button that is large enough to make it impossible for anybody to miss actuating it.
• Ensure that the emergency stop push button is the larger button than the other controls when it is placed on a panel.
• Separate the emergency stop push button from the other controls on a panel.
• Avoid using other colors aside from red and don’t use the same color on other controls.
• For practical reasons, the emergency stop push button should be round as much as possible.

Machines with separate controls

23. What is the difference between the emergency stop push button system than the cycle stop system?

Both systems are oftentimes mistakenly considered as similar systems but they are completely different.

The emergency stop push button system removes the power from the machine and this makes the machine stop while the cycle stop system is a command function that brings the machine to a graceful stop before an operating cycle is completed.

In a cycle stop system, the machine is usually on an automatic mode where it can restart its operating cycle once again after the stop.

It is also called a controlled stop because it stops the machine while retaining the power supply during the stop process.

While the emergency stop push button system stops the machine which is manually initiated, no power is supplied and used for emergency purposes.

24. Can you use the emergency stop push button for energy isolation?

The direct answer is no.

Although about 50 years ago, most people would believe that the emergency stop push button can be used to isolate an energy source but it is not the case.

This belief could be rooted in the HECP or Hazardous Energy Control Procedure called the lockout procedure where machines have padlocked emergency stop push buttons.

The padlocks prevent unauthorize resetting of the machines which are not ready for testing yet and for some reason, it was believed to be energy isolation devices.

HECP understands that normal safeguards could be bypassed or temporarily disconnected hence the lockout procedure was implemented.

One of the current standards, CSA Z460-05 [2], explains that an energy isolating device is a device that stops the halts the transmission or release of energy such as a circuit breaker, disconnect switch, conductor disconnect switch, line valve, a block, and other devices that are used to block electrical energy but not push button devices and other control type devices.

25. Can the emergency stop push button withstand water entry?

Yes, there are emergency stop push buttons that are waterproof.

Usually, they carry a seal that indicates the level of water and dust protection it has such as IP68 or IP69K, and these seals are considered dustproof and waterproof.

For example, waterproof emergency stop button, weatherproof emergency stop button, and outdoor emergency stop button.

The IP stands for Ingress Protection while the number figures represent the level of protection against solid and liquid entry.

IP69K sealing