THE TYPES OF VALVES USED IN STEAM PIPELINES
In addition to processing food, chemicals, and other things, steam is utilized to create power. It can also be used for heating, humidifying, and cleaning. For this reason, in the majority of control-related applications, steam control valves are indispensable. Steam control valves are often used to lower the steam pressure at the inlet. Steam valves are not only capable of controlling pressure, but also temperature.
In industrial processes, steam is often employed at lower pressures. Steam pressure regulates temperature because low-pressure steam has more latent heat than high-pressure steam. Temperature and steam pressure are correlated. Increased plant safety will result from the decreased steam pressure. Using steam for process heating has various benefits such as high efficiency, reliability, and simplicity of the system, making steam a preferred choice for modern process designers. A state-of-the-art automated valve helps maximize delivery and process efficiencies by adjusting steam pressure and flow.
STEAM VALVES
The most popular industrial steam valves are shown below.
GLOBE VALVE
The shutoff element of a globe valve is pushed vertically into and out of the seat. Globe valves are linear motion shutoff valves. Regardless of its form, the closing member is frequently referred to as a disc. The disc travel is directly proportional to the seat opening. This proportionate connection between disc motion and valve opening is perfect for tasks requiring flow rate control. Globe valves are commonly utilized in tiny pipes and are best suited for regulating and controlling fluid flow.
APPLICATIONS
Globe valves are frequently employed for a variety of uses. Practical uses include high point vents, low point drains, lubricating oil reservoirs, feedwater, and chemical containers where pressure drop is not a concern and leak tightness and flow control are of the utmost importance. Steam lines, wastewater, and power and process facilities are further applications for globe valves. Additionally, structures need upstream fluid flow for devices like water heaters.
ADVANTAGES
1)Exact control and throttling.
2)Limits of high pressure.
3)It has the potential to act quickly.
DISADVANTAGES
1)Increased head loss.
2)A sizable aperture for the disk assembly.
3)Thicker than typical valves.
4)The disc is mounted to the stem cantilevered.
5)Low coefficient of flow.
6)Not appropriate for sterile or clean applications.
A ball valve, which employs a rotating ball that has been drilled, regulates the flow of either liquid or gas. By turning the sphere 90 degrees on its axis, fluid can either flow out or be prevented. They have a long service life and provide dependable sealing for the whole of their life, even when the valve is not in use for extended periods of time. And for that reason, cutoff valves are more widely used than gate valves. In rare circumstances, control valves are employed in place of ball valves. However, because of the comparatively low accuracy of the rate control, this use is less prevalent.
ADVANTAGES
1)Opens and closes quickly
2)More compact and lighter than a gate valve
3)Offers service that is bubble-tight.
4)Various ball valve designs offer versatility in choice and can be applied to both clean and slurry applications.
5)The multiport design lowers the required number of valves while offering versatility. Furthermore, less force is needed to operate the valve compared with the gate/globe valve.
Premium ball valves offer dependable performance in high-temperature and high-pressure applications.
DISADVANTAGES
1)Unsuitable for applications requiring prolonged throttling
2)In slurries or other applications, airborne particles can settle and become lodged in body cavities, leading to wear, leakage, or failure of the valve.
APPLICATIONS
Ball valves are commonly used in high point vents and low point exhausts in liquid, gas, and other fluid services. instrument root valves, steam service, air, liquid, and gas applications needing bubble-tight service, and cooling water and water supply systems.
Ball valves and butterfly valves share a very similar operating mechanism. But the butterfly is nothing more than a disk fastened to a pole. When the valve opens, the disc is rotated back to permit flow, and when the valve closes, the stem rotates the disc a quarter turn to a perpendicular position in the direction of flow. Butterflies are used for on-off or modulating services because of their lightweight, low cost, small installation footprint, high availability, and quick operation. We can operate these valves with a handle, gear or motorized actuator.
APPLICATION
Butterfly valves are widely used in sewage treatment, water and gas supply, fire prevention, culinary, pharmaceutical, chemical, and petroleum goods, among other various sectors and uses. These large-sized valves work well with liquids and slurries that have a fair amount of solids in them when handled at low pressure.
ADVANTAGES
- 1)Butterfly valves are compact and quickly open and close when activated.
2)The valve requires less structural support of equivalent diameter and the disc is lighter than the ball valve.
3)The butterfly valves are useful in industrial applications because of their exceptional accuracy.
4)They are quite dependable and require very little upkeep.
DISADVANTAGES
1)Even when the disc is entirely open, a portion of it is exposed to the flow.
2)The throttle always operates by driving a pressure switch through the valve,
regardless of the position.
3)The thicker liquids might cause the disc to cease moving.
Gate valves are linear motion valves that produce shutdown by sliding a flat closure piece into the flow stream. Gate valves can be broadly classified into two categories: wedge and parallel. A flat disc gate is positioned between two parallel seats (upstream and downstream) in similar gate valves. A gate valve's primary benefit is its unobstructed, straight path, which reduces the pressure loss across the valve. In pipe cleaning processes, a gate valve's free bore permits a pig's passage. Gate valves should only be used in the fully open or closed position; they should not be used to control flow, as they are slower than quarter-turn valves.
APPLICATION
Gate valves find widespread use in various industrial sectors, such as oil & gas, manufacturing, pharmaceuticals, automotive, and maritime. Because they don't take up more room, non-rising stem gate valves are highly common on ships, in subterranean applications, and in situations where vertical space is limited. Harsh conditions, like those with high temperatures and high pressure, can be utilized for gate valves. They are frequently used in offshore applications, mining, water treatment, and power plants.
ADVANTAGES
1)minimal resistance to flow.
2)Low torque is used for both opening and shutting.
3)It can be used in the ring network pipeline medium to flow in two different directions.
4)The medium can flow in any direction without constraint.
5)The sealing surface of the working medium is less worn when it is entirely open.
6)The body has a straightforward structure. The production process is improved as a result.
7)There is hardly much structural length.
DISADVANTAGES
1)Constraints on pressure.
2)Poor hygiene.
3)Low-cutoff voltage.
4)There is more room for installation and greater significance in terms of overall size and opening height.
5)Friction and abrasion of the sealing surface are more important during opening and closing.
6)Its two sealing surfaces make maintenance, grinding, and processing more challenging.
7)Its opening and closing take longer.
Angle seat valves are piston valves that are pneumatically driven and offer linear actuation to remove the seal from its seat. The seat is positioned beneath a corner in the open position, which somewhat impedes the flow. There would be minimal pressure drop and good flow as a result. Industrial angle valves control the flow of aggressive fluids, steam, vacuum, and gases. They can function at zero differential pressure, at extreme temperatures, and with fluids with a high viscosity.Angle seat valves are a popular option for heavy-duty applications because of their durable design and lengthy service life. They are therefore superb and long-lasting. These valves can also be used in place of solenoid valves, particularly in situations where the latter are prone to failure due to viscous and polluted fluids. Angle valves have different pressure ratings depending on whether they are operated in a single or double-acting arrangement.
ADVANTAGES
1)Low-pressure decreases result in high flow rates.
2)Removing water hammers and preventing backflow
has a longer lifespan than ball valves.
DISADVANTAGES
The allowed differential pressure decreases with increasing channel size because it maintains the single seat valve structure.
APPLICATIONS
Millions of operating cycles can be achieved by the angle valves in demanding applications like steam, water, and aggressive media. With an anticipated lifespan of more than 10 million cycles, it is perfect for vacuum applications and can be utilized in fast-acting applications up to 1000 cycles per hour. They are mostly utilized in food and beverage, sewage, oil and gas, chemicals, and water.
DIAPHRAGM VALVES
Diaphragm valves stop the flow of the valve by using a flexible diaphragm and a "pinch" mechanism. The ability of diaphragm valves to isolate their constituent parts from the process fluid makes them perfect for hygienic applications, which is one of their main advantages. Nevertheless, the highest temperature at which diaphragm valves may operate is 450° F.
APPLICATION
- Wastewater and water
- Paper and pulp
- Power
- Cement
- Chemical
- Minerals and mining
- Bioprocessing and Pharmaceutical
ADVANTAGES
1)Leak-proof seal.
2)Maintenance ease.
3)This kind of valve can be repaired without stopping the pipeline.
closed off tightly.
4)Leakage into the environment is decreased.
DISADVANTAGES
1)It is only suitable for usage at modest pressures of up to 300 psi.
2)It works well in moderate temperatures between -60 and 450 F.
3)They aren't suitable for multi-turn tasks.
4)They should be made of materials that resist corrosion.