Inconel Valve

What is Inconel valve? 

An Inconel valve is a valve that is made of Inconel alloy. The Inconel is a nickel-based super alloy. The material has excellent oxidation resistance, corrosion resistance, high strength at high temperatures, and resistance to creep. This material strengthens the valve even at elevated temperatures. The melting temperature of this material is 938 ^oC which makes its use versatile in a wide range of temperatures. However, Inconel valve has the disadvantage of being heavy since Inconel alloy has high density of 8200 kg/m³. The valve operates manually or automatically. For manual valves, the valve comes with a handwheel or hand lever. The valve operator applies rotary force on the handwheel to open or close fluid flow. Inconel valve manufacturers design the valve to operate with a ball or disc component. The work of the ball or disc component is to close or open fluid flow through the valve. Some of the applications of this valve include oil and gas industry, salty water, marines, petrochemicals and chemicals, pharmaceuticals, among others.

Types of Inconel valves 

Inconel ball valve 

This is the valve whose closing component is shaped like a ball. This is one of the most commonly used valves because of its ease of use, repair, and maintenance. Depending on user preference and the service area, the valve operates manually or automatically. The automatic version uses an electric or pneumatic actuator. The manual valve has a handwheel where the operator applies force to open/close flow. A shaft component known as stem connects the handwheel or actuator to the ball.

Figure: Inconel ball valve and its components.

How does an Inconel ball valve work? 

An Inconel ball valve is one of the quarter-turn valves. It is a quarter-turn valve because it makes a 90^o rotation of the ball to either open or close flow. When the handle is rotated in the anticlockwise direction, the valve shaft or stem rotates in the same direction for 90^o degrees. As such, the ball makes a quarter-turn angle that aligns the bore at its center with the pipe connected to the valve. Aligning the ball bore to the valve leaves the valve open, and thus, fluid flows through the valve. When the handle is rotated clockwise for a quarter turn, the ball rotates and its bore becomes perpendicular to the fluid flow direction. As such, the ball and valve seat form a tight seal preventing any fluid flow.

Figure: working of Inconel ball valve; open state (left) and closed state (right).

Advantages of Inconel ball valve 

• They are easy to operate; just a quarter turn, and the valve will either open or close as you need.
• Versatile in size.
• Low-pressure drop unlike other valves like Inconel globe valves.
• Simple design makes repair and cleaning easy.

Disadvantages of Inconel ball valves 

• The ball gets damaged where the fluid contains some abrasive solids.
• It is prone to water hammer due to quick closing/opening.

Inconel butterfly valve 

This type of valve uses a rotary disc to allow, stop or control fluid flow in the piping system. Inconel valve manufacturers design this valve with a rotating disc mounted at the center of fluid flow path. The disc motion is controlled via a handwheel or actuator. This valve is among the quarter turn valves since rotating the disc for 90^o degrees closes or opens flow path. It is best for on-and-off applications. Using this valve for throttling is limited depending on the area of application and flow pressure. Various types of this valve are selected depending on pressure and flow rate to meet the piping system demands.

Figure: Inconel butterfly valve and its components.

How does an Inconel butterfly valve work? 

The working principle of this valve is the same whether it is manual or automatic. When the operator turns the handwheel for 90^o degrees in the anticlockwise direction, the valve stem or shaft rotates for the same angle. Since the valve disc is connected to the shaft/stem, it also makes the same angle. This angle leaves the valve open, and thus fluid flows through. When the handwheel is rotated in the clockwise direction for a quarter turn, it causes the valve disc to close the valve by making a tight seal with the valve seat. In this condition, the valve is closed and is no fluid flows through. For throttling, the valve operator turns the handwheel partially to allow some fluid flow.

Advantages of Inconel butterfly valve 

• They open/close fast.
• They are of simple and compact design.
• They use less amount of material and are thus light in weight.
• They can handle significant flow rates at low pressure.
• They can be used in fluid containing slurries and sludge.

Disadvantages of Inconel butterfly valves 

• The use of this valve for throttling is not recommended for high-pressure flows.
• It has some significant pressure drop.

Inconel plug valve 

This is a valve that uses a rotating plug to control fluid flow. This valve is shaped like a cylinder or cone. Inconel plug valve manufacturers design this type of valve with one or more passageways for the fluid to flow through. Having more than one fluid flow passage makes this valve serve the work of two or three valves, and this helps to save on cost. This valve is among the quarter-turn valves since it operates by turning the handwheel for an angle of 90^o degrees to open or close fluid flow as necessary.

Figure: Inconel plug valve and its components.

How does an Inconel plug valve work? 

An Inconel plug valve operates manually or automatically. The working principle remains the same whether it is manual or automatic. When the valve has to allow fluid flow, the valve operator rotates the handwheel in the anticlockwise direction. This rotation makes the handwheel rotate the valve stem for a quarter turn. Since the stem and valve plug are connected, the plug makes the same rotation. This rotation helps to align the plug’s middle hole to the pipe, and thus fluid flows through. When the handwheel/handle is rotated clockwise for another quarter turn, the plug’s middle hole becomes normal to the pipe connected. As such, the plug and the valve seat create a tight seal that ensures zero fluid flow through the valve.

Advantages of Inconel plug valves

• It opens/closes quickly by rotating the handwheel for a quarter turn.
• It offers a tight seal free from leakage.
• Simple and compact design.

Disadvantages of Inconel plug valves 

• It has some pressure loss due to the decreasing plug port.
• Heavy relative to the ball and butterfly valve.

Inconel gate valve 

This type of valve uses a disc that is shaped like a gate or has a wedge shape. This type of valve operates by moving the disc perpendicular to the direction of fluid flow. Inconel gate valve manufacturers design this valve for shut-off use only. Using this valve for throttling makes it vibrate and make noise which damages the disc and leads to leakage. As such, this valve is used when it is fully open or closed. When fully opened, there is minimal flow resistance and thus low-pressure drop.

Figure: Inconel gate valve and its components.

How does an Inconel gate valve work? 

This valve operates by moving the valve disc/gate upwards and downwards to open and close fluid flow respectively. When the handwheel is rotated in the counterclockwise direction for several turns, it rotates through valve stem threads as it moves upwards. This upward motion on the stem makes the valve gate/disc move up, leaving the valve open. As such, fluid flows through the valve. When the handwheel is rotated in the clockwise direction for several turns, the stem and the valve gate move downwards. The downward motion forces the gate and the valve seat to form a tight seal that prevents fluid flow.

Figure: Working of an Inconel gate valve.

Advantages of an Inconel gate valves

• It is suitable for bi-directional flow.
• It has a low-pressure drop relative to the globe valve.
• It is ideal for high pressure and high temperatures.

Disadvantages of Inconel gate valves 

• It occupies a large area when installed.
• Lapping and grinding repair is hard to perform.

Inconel globe valves 

The Inconel globe valve is designed to regulate fluid flow in a piping system. It consists of a movable disc component that controls the flow. The valve body is spherical which led to the name “globe vale”. The valve seat works with the disc to enhance a tight seal when the valve is closed. Inconel globe valve manufacturers design this valve for manual or automatic operation, depending on the application area.

Figure: Inconel globe valve.

How does the Inconel globe valve work? 

This valve operates similarly to the gate valve but does not need many turns to open/close. The valve opens when the handwheel is rotated in the anticlockwise direction. This rotation is converted to linear upwards motion by the valve stem. Movement of the stem upwards moves the valve disc up, leaving the valve open for fluid to flow through. When the handwheel is rotated slightly in the anticlockwise direction for throttling, the disc leaves some small space for some fluid to flow through. When the handwheel is rotated clockwise, the stem and disc move downwards. This leads to a tight seal that prevents any fluid flow.

Figure: Working of an Inconel globe valve.

Advantages of Inconel globe valves 

• It is the best for throttling.
• It is easy and fasts to operate.
• It is free from fluid leakage.

Disadvantages of Inconel globe valves 

• It has a lot of pressure drop compared to other valves.
• Its design is quite complicated.

Applications of Inconel globe valves 

These valves are used in many industrial applications, among them:

• Steam power plants.
• Foods and beverages.
• Pharmaceuticals.
• Agricultural applications.
• Municipal and desalination water systems.
• Mining applications.
• Oil and gas industries.
• Marine applications.
• Petrochemical and chemical processing.

Advantages of Inconel valves 

• These valves are robust.
• They are suitable for high pressure and high temperature.
• They are versatile in size and application.
• They are resistant to corrosion and oxidizing products.
• They are highly durable if used as per manufacturer’s instructions.

Disadvantages of Inconel valves 

• They are heavy relative to titanium valves.
• They are more expensive than titanium and stainless steel valves.

Troubleshooting Inconel valves

Leakage through the valve-pipe joint 

• Loose connection. Tighten the screws or bolts and nuts connecting the valve to the pipe.
• Worn out gasket. Replace the gasket.
• High pressure. Use the valve at the pressure recommended by the Inconel valve manufacturer.

Zero fluid flow through the valve 

• Blocked suction pipe. Check the line feeding the valve for blockage and remove any foreign material.
• Blocked valve. Disassemble the valve and remove any material inside the valve.

The valve is hard to close/open 

• Dirt-laden seat or disc/ball. Clean off the dirt on the seat and the disc/ball.
• Damaged stem. Replace or repair the stem.

The valve does not close completely 

• Foreign materials inside the valve. Clean off the foreign materials.
• Bent or damage on the valve stem. Repair or replace the stem as necessary.

Summary 

An Inconel valve is a valve that is made of Inconel alloy. The Inconel material has superb chemical and mechanical properties. These valves are robust enough for high-temperature and high-pressure applications. They have excellent corrosion resistance to adverse corrosive media such as hydrochloric and sulfuric acids. These properties make the valve long-lasting and economical to use. Depending on the use area, the valve is designed to operate manually or automatically. The working principle remains the same whether the valve is manual or automatic. The valve works using a ball or disc/plug component that opens and closes fluid flow as necessary. Turning the handwheel in the anticlockwise direction opens the valve, while rotation in the clockwise direction closes the fluid flow.

Inconel valve manufacturers have various valves, such as ball, plug, butterfly, globe, and gate valves. These valves are used in various applications, such as chemicals, agriculture, steam power plants, oil and gas, foods and beverages, and pharmaceuticals among others.