Socket Weld Ball Valve 

What is a socket weld ball valve? 

A socket weld ball valve is a type of ball valve with socket weld. A socket weld is a recessed area of the ball valve where a pipe is inserted. Socket weld ball valves are made of steel for applications involving higher pressure and higher temperatures that do not need disassembling. Socket weld ball valves are good in that they ensure leakage-proof connections that span for a long period. Socket weld ball valves have the welded end formed with a socket shape. The socket end of the valve is inserted into the pipe and then welded into the socket weld ball valve. Socket weld ball valves are used for small pipe diameters of around 2 inches or smaller. Socket weld ball valves are important in cases where high structural strength and leakage integrity are paramount design considerations. 

Figure: Socket weld ball valve.

Components of socket weld ball valves 

Valve body 

The valve body is the main component of a socket weld ball valve which houses all the internal components of the valve. The valve body serves as the valve pressure barrier. As such, it is always necessary to make the valve body with materials to ensure that the pressure cannot damage the valve. The valve body contains the ports in which the socket weld ball valve is connected to the pipe. 

Handle

The handle is the component of a socket weld ball valve which is used by the valve operator to apply the force to open/close the valve. The handle is made of strong material so that it can withstand the torque used to open/close the socket weld ball valve. 

Stem 

A valve stem is also known as the shaft. The stem in a socket weld ball valve is the component that connects the handle and the valve ball. The stem is also made of strong material so that it can be able to transmit the torque needed to open/close the valve as well as withstand the high pressure and high temperature the socket weld ball valve may experience while in use.

Ball  

The ball in a socket weld ball valve is the component used to enhance flow and blockage of fluid. The ball has a hole in its middle section which aligns with the pipeline to allow fluid flow. 

Seats 

Seats are components in a socket weld ball valve placed between the ball and the valve body and used to prevent fluid leakage. The seat is also used to support the ball in its position. 

Packing 

Packing is a seal placed around the stem of a socket weld ball valve to prevent fluid leakage. 

How does a socket weld ball valve work? 

A socket weld ball valve consists of a ball with a bore at its center. The ball is connected to the valve stem and handle. Fluid flow in a socket weld ball valve flows through the bore in the ball. To start the socket weld ball valve, the handle is turned for a quarter turn equivalent to 90^o. Since the handle in a socket weld ball valve is connected to the ball through the stem, rotation of the handle at 90^o rotates the stem and ball for the same 90^o. As such, the rotating ball bore becomes collinear with the pipeline such that the fluid can flow through the piping system through the socket weld ball valve. In this case, the socket weld ball valve is said to be in an open state. To turn off the socket weld ball valve, the handle is rotated in opposite direction for another 90^o. This makes the stem and ball on the socket weld ball valve make a quarter-turn of 90^o. When the ball makes this quarter-turn angle, it makes the ball bore perpendicular to the pipe with fluid thus blocking fluid flow. Thus the socket weld ball valve is said to be in a closed state. 

Figure: Working of a socket weld ball valve.

Types of socket weld ball valve? 

V-port socket weld ball valve 

This is a socket weld ball valve with a V-shaped bore in the valve ball. The “V” denotes the seat and ball design used. This type of socket weld ball valve provides efficient opening and closing of fluid flow. The flow in a V-port ball valve is almost linear. When the V-port socket weld ball valve is closed and an opening is started the small end of the V hole opens first allowing stable flow control. A V-port socket weld ball valve needs a strong valve construction due to high fluid velocities which can damage a standard ball valve. When a V-port socket weld ball valve is properly machined, it offers a leakage-free performance. 

Figure: V-port socket weld ball valve.

Three-piece socket weld ball valve 

A three-piece socket weld ball valve consists of three pieces that is the body and two end caps. The three pieces of a socket weld ball valve are held together using bolts and nuts. The socket ends of the socket weld ball valve are welded to the pipeline. A three-piece socket weld ball valve makes it possible to easily remove the center parts of the valve that is ball stem and seats from the pipeline. This makes it possible for the valve operator to clean deposited solids, replace gland packings and seats, and polish ball scratches without the need to remove the valve body from the pipeline. As such, a three-piece socket weld ball valve can be serviced and cleaned easily without the need to remove them from the pipeline. Three-piece socket weld ball valves can be used in industries where sanitation is very important such as pharmaceuticals and food processing applications. However, three-piece ball valves are very expensive relative to other socket weld ball valves. 

Figure: Three-piece socket weld ball valve.

Reduced bore socket weld ball valve 

This is a socket weld ball valve in which the ball bore diameter is less than the pipe diameter. This type of socket weld ball valve has a reduced bore with a venturi-shaped passage. Because of the reduced ball bore, the socket weld ball valve experiences friction losses. Reduced bore ball valves are used where drop in pressure, flow turbulence, and material characteristics are not a major concern. Reduced bore socket weld ball valves are of lower cost and have a smaller size. Reduced bore socket weld ball valves are suitable for use where flow rate has no strict demand to help reduce the cost and weight since these valves have relatively lower weight. 

Full port socket weld ball valve 

This is a socket weld ball valve that has the ball bore diameter the same size as the pipe diameter. This type of socket weld ball valve helps to reduce fluid resistance as the fluid flow from the pipeline through the valve is almost linear which reduces fluid turbulence. However, the cost of a full port socket weld ball valve is higher relative to other socket weld ball valves. Full-port socket weld ball valves are suitable where low fluid flow resistance is important such as in pump suction pipes in which loss of pressure can affect the performance of the pump. 

Forged socket weld ball valve

This is a socket weld ball valve made through the forging process. The socket weld ball valve of this type is made by heating the metallic material to high temperatures until it melts then a mechanical force of press is used to shape the valve to the required shape. The forged ball valve after being manufactured is tested using non-destructive tests (NDTS) to ensure it has no defects or pores where fluid can leak through. Once the valve body is manufactured it is assembled with other components such as balls, seats, packing rings, and handle.

Welded body socket weld ball valve 

A welded body socket ball valve is a ball valve made through welding method. This type of socket weld ball valve ensures that the valve body is free from leakage unlike bolted valves like three-piece socket weld ball valves. However, this type of valve is hard to service or clean while on-site. To clean or service a welded body socket weld ball valve, the valve needs to be removed completely from the pipeline. Welded body socket weld ball valves are suitable for use in underground or buried systems where no frequent maintenance is expected. NDTS test is also performed on welded body socket weld ball valve to ensure the valve is free from leakage. 

Applications of socket weld ball valves 

• Used in petroleum industries. 
• Oil and gas industries. 
• Water supply and irrigation systems. 
• Chemical admixtures and treatment. 
• Power plant generation of electricity. 
• These valves are used in HVAC systems. 

Advantages of socket weld ball valves 

• Easier to operate. 
• Versatile as they can be used in different industrial applications. 
• Small size and lightweight. 
• Cheaper relative to other ball valve types. 
• Leakage-proof. 
• Strong for most high-pressure and high-temperature applications. 
• Have low-pressure drop and a high flow rate. 
• Durable when used for the right media.

Disadvantages socket weld ball valves 

• Most of the socket weld ball valves cannot be inspected, cleaned, or repaired. 
• These valves are not suitable for fluid throttling. 
• Not suitable for use in large pipes more than 2 inches. 

Troubleshooting socket weld ball valves 

Leakage through the valve body

• Broken valve body. Replace the valve body or the whole socket weld ball valve as necessary. 

Leakage through the stem 

• Broken stem. Replace the stem. 
• Broken or worn-out stem packing. Replace the stem packing. 
• Misaligned stem. Align the stem properly. 

Leakage through the ball

• Damaged valve ball. Replace the ball. 
• Debris-laden ball. Clean or remove the debris.
• Ensure seat compatibility with the media.  

Leakage through the seats

• Worn out seats. Replace the seats. 
• Damaged seats. Replace the seats. 
• Debris on the seats. Remove the debris. 
• Chemical incompatibility with media. This causes the media to damage the seats; ensure the two are compatible. 

The handle is difficult to open/close 

• Damaged handle. Replace the handle. 
• Internal obstructions. Check for internal obstructions and remove them. 
• Broken stem. Replace the stem. 

Summary 

A socket weld ball valve is a type of ball valve connected to the pipeline using a weld connection. As the name suggests, a socket weld ball valve is manufactured with a socket weld. They are made of strong steel materials making them suitable for use in high pressure and high-temperature applications. One of the main advantages of socket weld ball valves is that they are leakage proof and durable.

Socket weld ball valves are made for use in small-sized pipes with diameters of up to 2-inch. They are of various types among them forged socket weld ball valves, welded body socket weld ball valves, three-piece socket weld ball valves, reduced bore socket weld ball valves, and full port socket weld ball valves. They are used in various applications among them oil and gas, water supply and irrigation system, power generation, chemical admixtures and treatment, HVAC systems among others.

Advantages of these valves are that they are quick to open/close, they are durable, they are free from leakage, they are small in size, light in weight, they are versatile, and they have high strength.