Lockout Tagout Equipment Type: A Practical Guide for Industrial Buyers
If you are a purchasing or safety supervisor in a factory, when you first come across the quotation from a LOTO equipment supplier, you are likely to feel that all the items look similar, but the prices differ by several times. Safety padlock, valve lockout, circuit breaker lockout, cable lockout,lockout tag... A long list is provided， with similar names but different purposes. 
This article won't go into theoretical explanations. Instead, it will categorize and explain each type one by one, informing you of what each type of equipment is used for and the potential pitfalls to be aware of during the procurement process. 
1. Safety padlock - The cornerstone of the entire LOTO system
A safety padlock is not the same as an ordinary lock. An ordinary lock can be opened by one key for several locks, but a safety padlock must ensure that one key can only open one lock. This is a basic safety principle and there is no room for negotiation. 
Several points to keep an eye on during the procurement process: 
Lock body material. Nylon is the most common type, lightweight, insulating, and corrosion-resistant, suitable for most conventional working conditions. However, if your workshop has a high-temperature environment (such as a foundry) or a strong acid-base environment (such as a chemical plant), you will need to choose an aluminum lock body or a stainless steel lock body. Steel lock bodies are durable but heavy, while brass lock bodies have poor corrosion resistance but good conductivity - each has its own applicable scenarios, and no one is absolutely better than the other.
Lock beam material and height. The lock beam is the U-shaped metal ring. Steel lock beams are the most common. However, if insulation is required, choose the nylon lock beam model. The common heights of lock beams are 25mm, 38mm, and 76mm. If the height is insufficient and the lock cannot pass through, it will be a waste of money when you buy it.
Key system. This is the most confusing part for procurement. KA (Keyed Alike) means all locks use the same key, which is convenient when one person manages a group of lock points. KD (Keyed Different) means each lock has a different key, which is necessary for group work. MK (Master Keyed) is an additional master key that can open all locks - individuals can open their own locks, and the supervisor can also open them in emergency situations. Decide which type you need for your scenario before purchasing; otherwise, you may find that you have bought the wrong one when you receive it.
Non-conductive lock body requirement. If your working environment has the risk of electric shock (such as power maintenance), clearly specify the requirement for insulation when purchasing. Some low-priced locks use ordinary engineering plastics instead of genuine insulation-grade materials. 
II. Lockout Valve Device
Valves are the most overlooked isolation points in the workshop. Often, merely closing the valve is not enough; the problem arises when others mistakenly open it after it has been closed. The valve lock is a device that "locks the valve in the closed position". 
By valve type: 
Ball valve lockout. The most common type. It is placed outside the handle of the ball valve, and after closing, it is locked with a padlock, making the handle unable to rotate. When purchasing, make sure to measure the width of your ball valve handle. The size differences between different brands of valves are quite significant. Some ball valve locks are universal and can be compatible within a certain size range; some are fixed and must match exactly. Universal ones are more expensive but more flexible; fixed ones are cheaper but more prone to being purchased incorrectly. 
Gate valve lockout. The handwheel of the gate valve is rotatable. The locking principle is to cover the handwheel so that it cannot rotate. Usually, it is a fan-shaped or bowl-shaped plastic cover that fits over the handwheel. When purchasing, make sure to check the maximum diameter of the handwheel that it can cover - gate valves range from DN15 to DN200, and the size difference is significant. 
Butterfly valve lockout. The handle of the butterfly valve is rather unique - it is a thin lever. The locking method involves fitting the handle into a sleeve so that it cannot be moved. Measure the width and thickness of the handle accurately. If these two measurements don't match, the lock won't work. 
The valve is a lockout valve. The handle of the valve is square. Before purchasing, take a photo and show it to the supplier to avoid making assumptions. 
A practical suggestion for purchasing a set of workshop valve locks at one go: First, conduct a thorough survey of all the valves, noting down the types, sizes, and handle designs of each valve. Then, ask the supplier to provide you with the corresponding ones - genuine suppliers are willing to do this. Don't place the order based on your own impression. 
III. Electrical Lockout Device
Electrical isolation is the most critical and error-prone part of the entire LOTO process. After the equipment has been repaired, someone simply closes the circuit breaker without removing themselves from the area - such accidents occur every year. 
Breaker lockout. There are many types, corresponding to different breaker models. There are those with snap-on mechanisms, clamped onto the switch lever; there are those with pin mechanisms, passing through the holes on the switch panel to lock; and there are universal types, locked with a cable tie or a clamp on the switch. The safest approach is: take a photo of your breaker panel and send it to the supplier for them to recommend the corresponding model.
Plug lockout. If the power supply of the equipment is plug-in (rather than hard-wired), unplugging the plug and locking it is a more thorough isolation method. The plug lock is a box that holds the plug in and closes it, with a padlock outside to prevent anyone from inserting the plug back. When purchasing, check the plug size - three-hole, four-hole, five-hole. Industrial plugs are much thicker than household ones. 
Wall switch lockout. Some old workshops use wall-mounted switches with special cover plates that lock onto the switch panel. This item is not expensive, but many workshops are completely unaware of its existence. 
IV. Cable Lockout Device
The cable lockout is essentially a flexible steel cable combined with a locking mechanism. Its advantages lie in the fact that it can pass through multiple isolation points simultaneously, and one lock can secure a group of items. 
When should we use cable lockout instead of individual locks? 
The equipment has multiple energy isolation points, and they are scattered in different locations.
The spacing between the valve handles is irregular, and the standard valve lock sleeves cannot be installed.
There are points that require bypassing obstacles to be locked.
Procurement notes: Diameter and length of the steel cable. A too thin diameter is prone to being cut, while a too thick one cannot pass through certain small holes. The length should be selected to be longer than the actual requirement by a certain margin, as the wiring paths on site are rarely straight. 
V. Hasp (Locks)
The Hasp are the core tool for the group work. It is a metal bucket plate with multiple lock holes (commonly 6 holes). Each person involved in the maintenance hangs their own lock on it. As long as there is still one lock on the bucket, the bucket cannot be opened and the equipment cannot be started. 
Key feature: The Hasps must be fully fastened with all the locks of everyone before they can be operated. They cannot be attached randomly. Each person independently manages their own locks and keys. 
When buying the clasp, pay attention to two parameters: the number of holes and the material. The number of holes determines how many people can be locked at the same time. It is recommended to buy one or two more holes than the actual number of people you have - just in case someone is added temporarily. In terms of material, steel is the most durable, while nylon is lightweight and insulated.