What are the advantages of API ball valve seat commonly used in what areas? In this article, we will explore the advantages of ball valve seats that are commonly used in long-distance oil and gas pipelines.
The seat and disk together help determine the performance of a valve. Valve manufacturers forge or weld the seat in a body, or it can be machined to shape.
1. Excellent abrasion resistance
The excellent abrasion resistance of API valve ball seat commonly used in what areas will help you keep your piping system operating safely. It can withstand severe service conditions that include high temperatures, erosion, abrasion and high pressure.
Floating ball valves, especially those with a PTFE (Teflon) based seat, are common in many processes where harsh chemicals or fluids are present. They have a very low friction coefficient, so they can be self-lubricating and do not require sealing lubricant in order to operate effectively.
A number of different coatings can be used on the ball and seat, including a stellite coating (commonly referred to as Stellite) which offers excellent mechanical wear resistance and good corrosion resistance. Cobalt overlays (commonly referred to as Chrome Plating) are also widely used. These are applied by a Plasma Thermal Arc process which creates a good bond strength and a low porosity coating surface.
2. Excellent chemical resistance
PTFE is the most common material used for ball valve seats because of its excellent chemical resistance. It is also very easy to clean and can withstand repeated exposure to steam and hot water.
This material is available in filled or unfilled grades for improved wear properties and thermal conductivity. It can be welded or machined to a wide range of dimensions.
Carbon filled PTFE has a higher pressure and temperature rating than unfilled TFE and offers better abrasion resistance. It is recommended for steam service -50degF to 450degF and can be used in oil-based thermal fluids.
Carbon reinforced PTFE has a lower melting point than virgin PTFE which reduces cold flow and porosity, but does not have the same chemical and torque resistance as other materials. This is especially true for high torque, automated applications.
3. Excellent temperature resistance
The seat material selection for valves can be based on a number of factors including the fluid, pressure and temperature. Some elastomers are not suitable for high temperatures because of irreversible changes to their physical properties.
This can be a challenge, especially when selecting the best valve for an application. However, the right choice will depend on a thorough understanding of what is needed in that area.
Metal-seated ball valves are an excellent option for applications where severe flashing, hydraulic shock and abrasive media exist. These valves can also withstand high temperatures up to 1,000deg F. They can be hardened by specialized coatings to further increase their resistance.
4. Excellent dimensional stability
Ball Carbide valve seat are designed to operate in a variety of environments and require a wide range of properties to perform correctly. These include low friction, ductility to provide reliable seals, good stress recovery and dimensional stability.
Many polymer materials are used for ball valve seats including PTFE, PEEK and UHMW-PE. PTFE is commonly selected for its chemical resistance and low coefficient of friction.
However, as pressure increases, PTFE cannot maintain its performance for very long due to the sensitivity of the seat material to slight deformation.
Manufacturers offer a variety of other polymer materials for ball valve seats such as PEEK, TFM, nylon and acetal. These materials are typically used for critical applications that require a high level of reliability in aggressive environments. They also need to be resistant to corrosive chemicals and temperatures.
5. Excellent oxidation resistance
In gas and oil production, ball valves are used in subsea isolation, pipeline surge control, processing separation, storage, transmission and distribution. They also are widely used in petrochemicals, mining and pulp and paper industries.
In these applications, V11-225 API pump valve ball seat are typically fabricated from materials such as 400 series stainless steel, which offers excellent oxidation resistance. They are also able to withstand high temperatures exceeding 1,000deg F, hydraulic shock, extreme flashing and abrasive process fluids.
By at least a 10:1 ratio, soft seated valves dominate the refining and chemical markets, but they are being slowly replaced by metal seated valves as the costs of these come down. However, they will likely continue to be the most cost-effective solution in relatively clean services under 450oF.
6. Excellent corrosion resistance
Metal-to-metal ball valve seats are designed for corrosive, high temperature and pressure applications. They offer tight shutoff and reliable, bubble-tight performance, even under severe conditions.
The right seat material is a critical factor in ensuring long-term valve reliability. Choosing the correct seat for your application requires complete understanding of your process condition and the corrosive, abrasive, or oxidizing nature of the fluid you are transferring.
Soft seats are usually thermoplastic materials like PTFE. These can be reinforced with glass or carbon fiber and can be formulated for a variety of process fluids.
7. Excellent pressure resistance
Choosing the right valve seat material is critical to the safety and integrity of any process. Whether you’re working in the oil and gas industry or in a pharmaceutical laboratory, a leak could be detrimental to your operation.
The API ball valve seat commonly used in what areas is known for its excellent pressure resistance. It is designed to withstand high pressure and high temperatures, which makes it an ideal choice for many industrial applications.
This type of seat is designed with a welded metallic seat holder that provides an additional seal in the event of the primary RPTFE seat failure due to a fire. This seat design is available in a range of sizes and configurations to suit different processes.
8. Excellent fatigue resistance
Besides excellent wear resistance, the API ball valve seat commonly used in what areas also has high fatigue resistance. It is able to withstand high-pressure, cryogenic or steam service without rupturing the seat.
The metal-seated design of a ball valve is becoming increasingly popular in severe service applications around the world. This type of valve is available in a wide range of body ratings and can be made with double block & bleed (DBB) or self relieving seat (SPE) configurations, which allow the sealing ability of the seats to be tested during installation and maintenance.
Unlike soft-seated valves, metal-seated ball valves use coatings to seal the seat ring against the metal ball and prevent galling. This can be achieved by a tungsten carbide or chromium carbide coating, electroless nickel plating (ENP) or by stellite hard facing.
9. Excellent corrosion resistance
In most valves, the disc is supported by a seat that seals against the ball and allows the valve to operate. This is an important design feature that can greatly affect a valve's performance and safety.
The seat material can be either a polymer or metal. The material choice depends on several factors, including the environment and the application's requirements.
For instance, soft seats are typically used in applications where process fluids can be dirty or abrasive. These seats are often made of polytetrafluoroethylene, which is a good option for those situations.
For more severe service applications, a metal-to-metal ball valve seat is often recommended. This design offers superior performance in abrasion, erosion and high temperature applications.
10. Excellent abrasion resistance
Metal-to-metal sealing is provided by the seat ring and ball to improve abrasion resistance. This type of valve is often used for abrasive service or services where soft seat material cannot be used due to temperature limitations.
These valves have a high level of abrasion resistance and are suitable for solid particle, sand, short fiber and slurry applications. They also provide better operating torque than their soft-seated counterparts.
A special stem on the trunnion-mounted valve makes the ball rotate after separation from the seat, which reduces abrasion between the ball and the seat during operation. This helps in lower operate torque and long life.
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