Locking Valves

Locking devices are essential in industries where valve operation is crucial for safety, process control, and equipment protection. Locking mechanisms are designed to secure valves in specific positions, preventing unauthorised or incidental operation. They provide an added layer of safety, ensuring that valves remain in their intended position and minimising the risk of process interruptions, equipment damage, and safety hazards. In this article, we discuss the various forms of locking devices for valves and their advantages in a variety of industrial settings.

Lockout/Tagout (LOTO) Systems for Valves

Lockout/tagout systems for valves are commonly used to isolate and secure valves during maintenance, repair, or service procedures. Typically, these systems consist of lockout devices and tags that signify the status of the valve and provide information regarding the work being performed. Common lockout/tagout devices include:

a. Lockout Hasps: Lockout hasps enable multiple workers to simultaneously lock out a valve. They have multiple shackle holes, allowing each employee to affix his or her own padlock to the hasp. This ensures that the valve is inoperable until all padlocks have been removed.

b. Valve Lockout Devices: Valve lockout devices are designed to fit over valve handles or levers, rendering them immobile in the desired position. They come in a variety of sizes and configurations to accommodate various valve types, such as ball valves, gate valves, and butterfly valves. Typically, these lockout devices are secured with a shackle to prevent unauthorised valve access.

c. Valve Lockout Kits: Valve lockout kits contain the lockout devices and accoutrements necessary for securing valves in a variety of circumstances. Typical components of these kits include lockout hasps, valve lockout devices, padlocks, badges, and other lockout/tagout essentials.

Tags and labels are used in conjunction with lockout devices to provide additional information regarding the status of the valve and the work being performed. Typically, they include information such as the authorised worker's name, the cause for the lockout, and the anticipated completion date.

2. Key Locking Systems

The purpose of key interlock systems is to assure a specific sequence of valve operations, thereby preventing accidental or unauthorised activation. These systems utilise mechanical keys that must be inserted into interlocking mechanisms in order to operate the valves. Key interlocking systems provide the following benefits:

a. Sequential Control: Key interlock systems enforce a predetermined valve operation sequence, preventing potentially hazardous or disruptive actions. In a process with multiple valves, for instance, the interlock system may require one valve to be closed before another can be opened, ensuring the correct flow of materials and preventing process upsets.

b. Personnel Protection: Key interlock systems protect personnel by assuring safe and controlled valve operation. This prevents the unintended discharge of hazardous materials or activation of equipment, thereby reducing the risk of injuries and accidents.

Protection of Equipment: Key interlock systems protect equipment by preventing unauthorised or inappropriate valve operation. This can protect sensitive equipment such as pumps, compressors, and heat exchangers from damage caused by incorrect valve settings or abrupt changes in process conditions.

d. Compliance with Regulations: Key interlock systems facilitate regulatory compliance, especially in industries with stringent process safety standards. By mandating proper valve operation and control, these systems assist businesses in adhering to industry-specific rules and regulations.

3. Padlocks and Locking Handles

In addition to specialised lockout/tagout and interlock systems, simple yet effective securing devices for valves include padlocks and locking handles. These devices are readily accessible and simple to implement, and they offer the following advantages:

Versatility: Padlocks and  securing handles are a versatile securing solution because they can be used on a variety of valves. They can be attached readily to valve handles, levers, and operating mechanisms to prevent unauthorised access or accidental operation.

Visual Deterrence

The presence of padlocks or locking handles serves as a visual deterrent, signifying that the valve is locked and should not be operated. This helps strengthen safety protocols and prevents unauthorised personnel from manipulating the valve.


Comparative to specialised securing systems, padlocks and locking handles are readily available and inexpensive. For fundamental valve lockout applications, they are readily available and deployable, providing a practical and cost-effective solution.

d. Accountability and Control Companies can establish accountability and control over valve operations by designating specific padlocks or locking handles to authorised personnel. This enables obvious identification of those with access to the valve and those responsible for its operation, thereby enhancing overall security and safety.

Locking devices for valves are indispensable for ensuring safety, preventing unauthorised operation, and meeting regulatory requirements in a variety of industrial contexts. Whether through lockout/tagout systems, key interlock mechanisms, or simple padlocks and securing handles, these devices offer additional protection for valves during maintenance, repair, or normal operation. By implementing effective locking solutions, businesses can increase workplace safety, secure the integrity of their equipment, and promote compliance with industry standards and regulations.