The oil and gas industry is significantly dependent on pipeline infrastructure for a wide range of activities, including refining processes and distribution. The industry places great significance on pipeline infrastructure and dependable control systems because of so many reasons. Any deficiencies or shortcomings in industrial valves in such systems might lead to significant financial losses, dangerous leaks, and perhaps catastrophic environmental disasters. Industrial valves play a crucial role in ensuring the secure operation of oil and gas pipelines. Their responsibilities include managing flow control and ensuring the integrity of supply lines, among other important duties. To get a comprehensive understanding of their functions and applications, presented below is an elaborate manual on various industrial valves for the gas industry.
Various Categories of Industrial Valves for the Gas Industry
At its core, industrial valves serve the purpose of facilitating the opening, restriction, control, or regulation of fluid flow. However, for all these elements of fluid flow to be achievable, certain valve design requirements are necessary. Therefore, industrial valves may be categorized as follows:
Disc Type Valves
Within this particular framework, a disc denotes the valve mechanism used for the regulation of fluid movement. However, using a diverse range of disc types in industrial valves is a crucial aspect of the design due to the following reasons:
- Various discs use distinct sealing processes that are effective for different types of material.
- They provide valve choices for pipelines of varying sizes.
- Various discs are configured to function as a remedy for certain pipeline issues.
Considering this, let us examine the many sorts of discs used in industrial valves for the gas industry:
- A ball valve is a kind of valve that utilizes a ball to control the flow of fluid and shut it off. The ball is often excavated in the center, either completely or partly, and manipulated using an actuator linked to a pivoting stem.
- A gate valve, as its name implies, is a planar metal disk that may be raised or lowered to control the flow of fluid. The structure is laterally supported by seats and connected to a stem at the upper end.
- A flat disk, similar to a gate but often round and rotating horizontally rather than vertically. Some industrial valves, such as check valves, operate autonomously according to the conditions of the pipeline, without requiring an actuator.
- A plug, specifically a plug disc, is capable of vertical movement to regulate the flow of fluid. The act of inserting this sort of disc into a precisely created hollow may be likened to filling a hole, which is why it is called as such. Typically, it is affixed to a stem.
- A needle may be defined as a more slender kind of plug disk. It is more advantageous in situations when there is limited room for pipelines and the pressure conditions are not too high.
- A diaphragm is similar to a plunger. It travels horizontally and is often composed of a polymer substance, distinguishing it from the aforementioned discs.
Valves are categorized by the materials used in their bodies
The selection of material for an industrial valve dictates its applicability. This is due to the inherent compatibility of each substance with certain medium.
Some major materials often utilized in valve manufacturing include:
Stainless steel
Stainless steel is a non-reactive metal. It contains chromium, nickel, and molybdenum in various amounts. Stainless steel ball valves like the CF8M can regulate the flow of corrosive substances like salty sea water, acids, and halide vapors. They do not cause corrosion or depreciation.
A cast steel valve is produced by the process of pouring molten steel into a mold and allowing it to harden under certain circumstances. If this technique is executed correctly, it results in durable valves and offers an economical and easy way of manufacture. Nevertheless, diligent supervision and meticulous examination are necessary due to the susceptibility of the material to develop gaps and rips, resulting in uneven solidification of the molten steel. Additionally, if the quality of the melted steel is below grade, the valve will similarly be unreliable.
Forged Steel
Forged steel valves are created by applying extreme heat and mechanical instruments to mold metals. Essentially, steel is manipulated and shaped into the form of a valve using tools instead of being poured into a pre-existing mold. An advantage of this is that the metal becomes more robust and durable as a result of being exposed to heat, resulting in stronger industrial valves. Conversely, as it is constructed as a whole entity, the interconnections between various components may potentially result in leaks. The additional tasks required are equally laborious and contribute to the high cost of forged steel valves.
Valves categorized by operating conditions
The characteristics of a pipeline determine the suitable industrial valve type for its application. Both the valve’s material and its disc must possess the ability to endure the conditions inside the pipeline without experiencing excessive wear and tear, while still maintaining the operational criteria. When selecting a valve, take into account factors such as:
Temperature Sensitivity
Temperature sensitivity is a critical concern in the oil and gas industry due to the flammability of petroleum products. For this purpose, valves used in petrochemical pipelines must possess the capacity to endure and sustain temperatures within favorable ranges. The valve design must also account for the phenomenon of thermal expansion and contraction in metals. To maintain the optimum performance of the valve, it is necessary to reduce temperature changes.
High-pressure levels in a pipeline may overpower an industrial valve that lacks the necessary resilience to withstand such circumstances. A needle valve, for instance, is unable to withstand the force that high fluid pressure exerts without being forced open. Therefore, in the event of elevated pipeline pressure, it is necessary to have a durable valve capable of withstanding such intense force. A fully welded ball valve, such as the one placed on a trunnion, is capable of withstanding high pressure while ensuring excellent performance and minimal torque.
Pressure relief
Pressure relief is crucial. High pressure may lead to pipeline ruptures or cause even the most durable valves to fail. Consequently, it could be essential to include a pressure relief valve in an oil pipeline. A check valve would be suitable for this circumstance due to its pressure sensitivity. The valve can remove accumulated air pressure or enable the passage of media in the pipeline, thereby relieving fluid pressure. A diaphragm valve, which functions as a throttling valve, is similarly beneficial since it enables the reduction of fluid pressure in specific areas.
Corrosive substances refer to the fact that crude oil is a mixture of several fuels. All of them ultimately separate themselves during the refining process. Certain components may possess a high level of corrosiveness, necessitating the use of valve materials – both resilient and non-reactive. Stainless steel valves or valves composed of improved steel alloys are perfect for the specific circumstances of pipelines.
