All About Fire Safety Valves Full-time JobJan 7th, 2022 at 07:39 Engineering Sascut 169 views
All About Fire Safety Valves
One of the more recent developments in industrial tools to prevent fire is the introduction of fire valve. These valves are designed to prevent a fire from spreading if the fuel valve gets damaged or causes a leakage.
A valve is a device that adjusts, directs, or controls the flow of a fluid by opening, closing, or partially blocking various passageways. Valves are technically a type of fitting but are usually discussed separately. In an open valve, fluid flows from higher pressure to lower pressure. The simplest kind of valve is simply a freely hinged flap that drops to obstruct flow one way but is pushed open by fluid flowing the opposite way. This ancient valve is called a check valve, as it stops or "checks" the flow in one direction. Modern valves may regulate pressure or flow downstream and operate on sophisticated automation systems.
Valves have industrial applications for controlling processes, residential uses such managing water flow to dish and clothes washers and taps in the home. They are found in almost every industrial process, including mining, water and sewage processing, power generation, food manufacturing, processing of oil, gas and petroleum, chemical and plastic manufacturing, and many other fields.
Fire-safe valves are spring-loaded valves that are thermally actuated. In case of fire, they close automatically and stop the fuel flow. The fuel flow from the crankcase of the engine and the reserve oil supply gets hindered, thus minimizing the chances of leakage.
Spring-loaded valves help with preventing the flow of fuel such as oil, gas, petrol, and other combustibles, and are useful and effective against any damage. The benefits of using fire landing valve in a system are the protection of human life, lower insurance rates, and the protection of equipment and the building.
It is because of these benefits that the use of these valves is highly recommended and appreciated. These days, many companies offer an extensive range of fire-safety valves to provide protection even in high temperature and high-pressure conditions.
How Fire Safety Valves Work
A fire safety valve aims to keep ignitable fluids away from a flame. These fire gate valve close when exposed to heat, separating a flammable liquid from the heat source. They close in the midst of overheating of the pipeline, brought on by fire or similar events. The obligation to use fire safety valves is subject to any tenets, regulations, and laws concerning the unique methodology, plant, pipeline, or vessel.
Fire-safe ball valves use a combination of a floating ball, graphoil seals, and metal-to-metal seating to provide tight shut-off while preventing external stem leakage. In normal working conditions, the ball rests against two seats, ensuring bubble-tight closure. When the valve is exposed to a temperature above the limits the seats can withstand (for example, +450°F), the seats become deformed and are subject to extrusion. When the seats have been completely destroyed, the ball in the valve will come to rest firmly against the end cap, producing a metal-to-metal closing. Stem seals, which have high temperature-resistant properties, further restrict leakage in conjunction with a blow-out-proof anti-static stem, so that the flammable fluid stays separate from the heat source that may ignite it.
A fire-safe valve may also be made up of four main mechanisms: a spring pack, a trigger assembly, mounting hardware, and a fusible link. The components work in unison to close the valve should a fire be detected within a facility. The fusible link is the key part of the assembly. It keeps the valve open by maintaining tension on a spring pack through the trigger assembly. When a fire breaks out, the fusible link separates once it is heated to a certain high temperature, which releases the spring pack and allows it to close the valve.
A fire-safety valve with fusible links has a primary drop-tight seat, usually made of TFE, along with a second seat made of metal for isolation in a fire. The secondary seat also has graphite seals for further protection. This means that the shut-off valves can be paired with any quarter-turn ball valve, butterfly valve, or fire ball valve.