Kinetrol Fire Fail-Safe Spring Units: An Important Solution for Valve and Damper Control in Fire Events

Providing failsafe mechanisms for valves in industrial process control systems is critical for several reasons, particularly when considering fire safety.

The operation of a failsafe mechanism depends on the specifics of the process and the process media. A valve might need to fail-open (default to the open position when power is lost) or fail-closed (default to the closed position when power is lost), depending on the nature of the process and the potential hazards involved. For example, in a fire situation, a valve in a cooling water system might need to fail-open to ensure continuous cooling to prevent overheating. In contrast, a valve in a fuel line might need to be fail-closed to avoid the release of fuel that could feed the fire. So, the design of failsafe mechanisms must meet each industrial process's specific needs and hazards.

Kinetrol Fire Fail-Safe Spring Units are critical safety components in industrial systems, designed to ensure the automatic opening or closing of a valve or damper in the event of a fire. The inherent capability of these units to initiate a controlled response under fire conditions provides an extra layer of security to the process control landscape.

Central to the functioning of these fail-safe units is a fusible link mechanism. A fusible link is a device used in electrical, mechanical, or process control systems that acts as a failsafe mechanism. Its primary function is to fail or react when exposed to a specific temperature, often associated with fire conditions. They incorporate a material or a combination of materials (usually metal alloys) with low melting points. Under normal conditions, the fusible link will allow the system to function as designed. However, when the ambient temperature around the fusible link reaches a specific threshold (due to a fire or other abnormal condition), the material of the fusible link will melt or break. This action, in turn, triggers the Kinetrol Fire Fail-Safe Spring Unit into operation, and depending on the design and requirement of the system, the spring unit will open or close the valve or damper. The automatic movement restricts or allows the flow of fluids or gases, aiding in fire control by either isolating hazardous substances or allowing the passage of fire suppression agents.

Fusible links are a simple and effective way to add a layer of safety to systems where fire risk is present.

Overall, the Kinetrol Fire Fail-Safe Spring Units, through their incorporation of fusible link mechanisms, offer a reliable and effective method of mitigating the risks associated with fire in industrial environments.

For more information, contact:
Kinetrol USA
https://kinetrolusa.com
972-447-9443

"Failure Is Not an Option" - Kinetrol Manual and Fire Fail-Safe Spring Units

If you want to operate a valve manually, but maintain the advantage of the fail-safe spring's certainty of position when unattended, check out the Kinetrol's manual and fire fail-safe spring handle. This uniquely designed manual operator offers some compelling benefits in automating valves and provides additional plant safety levels. Spring return (also known as "deadman") handles will help you meet individual plant safety requirements and OSHA requirements for valves that must return to the closed position after an operation. Unlike lever handle or gear operators that will leave the valve in the last state, the spring return deadman device ensures that the valve returns to its original starting position powered by the associated spring handle.

Kinetrol Manual and Fire Failsafe Handle from Kinetrol USA

The Advantages of Torsion Springs for Pneumatic Actuators

Kinetrol uses a torsion spring
as the motive force for
their actuator spring return.

Torsion springs, or clock springs, are helical shaped springs that exert a torque or rotary force. They are one of the the oldest forms of flat springs and one of the most common type in use today because of their simplicity and reliability.

Torsion (clock) springs posses a natural tendency to expand, producing a cumulative torque that increases as the spring is wound tighter. Both ends of the torsion spring are attached to other, separate components. When one component rotates around the center point of the spring, the spring will increasingly try to return to the original state.  When a torque is applied to a spiral torsion spring, an angular displacement is created between the first and second loading points. The coil then deflects (tightens), and the spring material is placed under stress, which in turn exerts a linear rotational "output" torque.

An internal view of the
 clock spring. You'll note
similarities with the
Kinetrol spring return unit.

Practically speaking, spiral torsion springs allow for lower torque loss, lower torque stress, and much greater reliability for use in valve and damper actuation.

Advantages of the torsion spring:

• High torque delivery per unit of deflection
• Low cost
• Compact
• Reliable
• Adjustable

Need a Fail-Safe Valve Operator? Use This One.

Kinetrol manual fail-safe
spring unit.

If you want to operate a valve manually, but maintain the advantage of the fail-safe spring’s certainty of position when unattended, use this device.

These spring return units are designed to be put on valves to prevent, or limit, the impact of potentially hazardous accidents resulting from uncontrolled flowing fluid and gasses or spillage.

The Kinetrol manual fail-safe spring unit has a ISO/DIN female drive for direct mounting and ATEX category 2 options for use in hazardous areas. Kinetrol also offers a range of fire fail-safe spring assemblies that can be set to operate valves at pre-configured temperatures.

Because they cannot be left in the wrong position, they are commonly referred to as "deadman handles". Theses devices provide reliable torque delivery for valve reseating and come with completely sealed spring housings that meet IP65 levels, totally protecting the internal spring from the environment, making them ideal for outdoor applications.

20" High Performance Butterfly Valve Closed in Under 1/2 Second!

Fast closing Kinetrol actuator

This video demonstrates how quickly a large butterfly valve can be closed with a Kinetrol vane actuator spring return unit. In this case, it's a 20" stainless steel high performance butterfly valve (HPBV) being tested in the shop.

You'll note the valve takes about 11 seconds to open, but only 0.4 seconds to close, using the Kinetrol spring return unit.

Quick closing valves are used in emergency situations to stop the flow of fluids that may contribute to uncontrolled combustion, cause backstream contamination, or allow spillage of hazardous materials.

Innovative Approach to Add Manual Failsafe Handles for Large Quarter-Turn Valves

Kinetrol manual failsafe unit

Let's assume you have an application where it's critical that a large, pneumatically actuated valve cannot be left unattended in the wrong position (opened or closed). Or maybe your application requires the use of a manual operator with a fire-safe fusible link. The problem though, is the valve you want to control has torque requirements much greater than the output of any manual failsafe unit can provide. 

Here's an innovate and effective way to incorporate a manual failsafe unit on large size ball, butterfly, or plug valves. 

Retrofit your large valve with a 3-way "L" port ball valve and a manual failsafe spring handle on the large valve actuator's inlet air supply port. 

This allows the opening of the valve with the manual failsafe handle. When the handle is released, the valve shuts automatically by venting the air to atmosphere, and allowing the springs in the actuator to close the valve. 

Size limitations on the valves are no longer an issue, and this will work on anyone's pneumatic spring return actuator (spring return required, will not work on double acting actuators). 

Manual Override for Larger Valves