Ball Valves: How It Works, Types And Common Applications

 

 

Ball valves are specially designed valves that are used in pipeline applications to turn off and on flow of a substance. For instance, they're commonly used in gas processing, plumbing and industrial piping systems to control the flow of a gas or liquid through a pipe. And they're also used in food and beverage systems, including in brewing, water pipeline systems and liquid food processing factories.

A ball valve is made up of several pieces, including a floating ball, stem, seat, and handle.

Here's how the system works: The valve features a pivoting ball, with an opening in the middle that is connected to a stem and handle. With a quarter turn of the handle, the ball's opening comes into alignment with the pipeline flow, enabling a liquid or gas to flow freely through the valve. When the ball opening is in the off position, the flow of a substance is blocked.

Ball valves are most commonly used because they provide fast, effective shutoff of a system. Plus, they are durable, provide a secure seal for long periods of use, and they're easy to repair and operate. Thus, these types of valves are often preferred over other quarter-turn stopping valves.

 

Common Types of Ball Valves

In general, there are five types of ball valves that provide a similar function and are operated the same. The biggest difference, though, is in body construction and how the balls are contained in the assembly's casing. Body styles include split body, top entry, single body, three-piece body and welded.

Plus, ball valves are also determined by the type of opening within the ball. Different types of bores result in added precision when turning off the valve, they can contain more than one open or closed setting, and they can be fashioned to prevent buildup behind the ball. The size of the bore, or port, can also be the same size as the pipeline or a reduced size, which results in a restricted flow. Bore types include:

Full Port Ball Valves: The floating ball of a full-port ball valve is oversized, and the bore is the same size as the pipeline. This results in the free flow of a substance, and that's why full port ball valves are commonly used in oil and gas pipelines, as a flow restriction can disrupt the material and cause buildup. These valves are larger, and thus they're more expensive.

Reduced Port Ball Valves: As known as reduced-bore or standard ball valves, the bore in this type of valve is smaller compared to the pipeline, and thus flow is restricted and pressure drops. These are typically used when flow rate is not a major concern. Plus, they're smaller and more cost-effective compared to full-port valves.

Cavity Filled Ball Valves: The constant flow of gas or liquid through a ball valve can result in buildup behind the ball. A cavity filled ball valve prevents this from happening. This type of valve has a seat, or casing, that completely surrounds the floating ball to prevent buildup. They're commonly used in systems where this buildup could result in bacteria, i.e. in brewing and food systems, or where a material can crystallize behind the ball like paint.

V Port Ball Valves: Instead of a cylindrical-shaped bore, the V Port ball valve has a v-shaped bore or seat. Thus, as the valve moves from off to on, the narrower end of the V is positioned in front of the flow, and slowly, as the wider parts of V-shaped bore reach the pipeline more material can flow through the valve. This results in greater precision and more control, compared to other styles.

 

Buyer's Tips

Choose a valve that will fit the size of your piping; there are ball valves available in all standard pipe sizes. Generally, standard, reduced-flow ball valves are the most typical type of valve available. Plus, you'll also want to choose a valve with the correct threading. The most common options include female-female threading, i.e. both pipeline openings would be male, or non-threaded valves, which are designed for PVC piping and other non-threaded materials.

 

At Changsong, you'll find a wide range of ball valves. Shop for the best prices in our wide ball valve selection right now.

What are slip rings and types of slip rings？

What is a Slip Ring?

A slip ring is defined as an electromechanical device that is used to connect a stationary system to a rotating system. It is used in applications that require rotation while transmitting power or electrical signals.

 

The slip ring also is known as an electrical rotary joint, rotating electrical connector, or electrical swivel. It is used in various electrical machines to improve mechanical performance and simplify operation.

 

If a device rotates for a fixed number of revolutions. It may be possible to use a power cable with sufficient length. But it is a quite complex setup. And it is impossible if components rotate continuously. This setup is not practical and reliable for this type of application.

 

How does a Slip Ring work?

The slip rings consist of two main components; metal ring and brush contact. According to the application and design of the machine, the number of rings and brushes is decided.

 

The brushes are made up of graphite or phosphor bronze. The graphite is an economical option but the phosphor bronze has good conductivity and more wear life.

 

Depending on the RPM (rotations per minute), the brushes are fixed with rotating rings, or rings are rotating with fixed brushes. In both of these arrangements, the brushes maintain contact with the ring by pressure from the springs.

 

Generally, rings are mounted on the rotor and it is rotating. And brushes are fixed and mounted on the brush house.

 

The rings are made up of conductive metals like brass and silver. It is a mounted shaft but insulated with a center shaft. The rings are insulated from each other by nylon or plastic.

 

As the rings rotate, the electrical current is conducted through the brushes. Therefore, it makes a continuous connection between the rings (rotating system) and brushes (fixed system).

 

Types of Slip Rings

Slip rings are classified into various types according to construction and size. Types of slip rings are explained below.

 

Pancake Slip Ring

In this type of slip ring, the conductors are arranged on a flat disc. This type of concentric disc is placed in the center of a rotating shaft. The shape of this slip is flat. So, it is also known as a flat slip ring or platter slip ring.

 

It will reduce axial length. Therefore, this type of slip ring is designed for space-critical applications. This arrangement has more weight and volume. It has greater capacitance and greater brush wear.

 

Mercury Contact Slip Ring

In this type of slip ring, mercury contact is used as a conducting media. Under the normal temperature condition, it can transfer current and electrical signals by liquid metal.

 

The mercury contact slip ring features strong stability and less noise. And it provides the most scientific and economical option for applications in industries.

 

But the use of mercury creates a safety concern. Because it is a toxic substance. It is very dangerous to use this type of slip ring in applications like food manufacturing or processing and pharmaceutical. This is because it may corrupt the product if there is a mercury leakage.

 

Through Hole Slip Rings

This type of slip ring has a hole in the center of the slip ring. It is used in devices that require transmitting power or signal when need 360˚ rotating.

 

This type of slip ring is designed to install with a flange on a sleeve bracket. It has free space in the center for connecting the shaft of a machine without affecting the cable while it is rotating.

 

It has a long life span and offers low noise and maintenance. This type of slip ring is used for routing hydraulic pneumatic passages and it can integrate with high-frequency joints.

 

Ethernet Slip Ring

This type of slip ring is developed to provide reliable products that allow the transfer of the ethernet protocol through a rotary system.

 

When choosing an ethernet slip ring for communication, there are three important parameters that must be considered; Return Loss, Insertion Loss, and Crosstalk.

 

Ethernet slip rings are designed to meet the requirement of matching impedance, reducing losses, and controlling crosstalk.

 

Miniature Slip Rings

This type of slip ring is very small in size and it is designed for small devices to transfer signals or power from a rotating device.

 

Miniature slip rings are ideal for electrical devices like control panels, video transmitters, and sensors.

 

Fiber Optic Slip Ring

This type of slip ring is designed to pass signals across rotating interfaces when a large amount of data needs to transfer.

 

The fiber optic slip ring is also known as the Fiber Optic joint or Fiber-Electric Rotary joint. This type of slip ring is used in applications like; sensor signal management, HD video transmission systems, radar, and video monitoring systems, medical equipment, microwave communication, etc.

 

Wireless Slip Ring

This type of slip ring is not using carbon brushes or friction-based metal rings. As the name suggests, it can transfer data and power wirelessly. For that, it uses the electromagnetic field.

 

The electromagnetic field is produced by the coils which are placed in the rotating receiver and stationary transmitter.

 

The wireless slip ring is the best alternative for the traditional slip ring as it reduced the mechanical contacts. Therefore, it can be used in harsh environments and reduces maintenance.

 

But the only disadvantages are that the power that can be transmitted between the coil is limited. The same volume of traditional slip rings can transfer more amount of power compared to the wireless slip ring.

The History of the Rotary Joint

 

 

Throughout the 19th and early part of the 20th century, the accepted method of supplying water or steam to a rotating cylinder was through the use of stuffing boxes or packing glands, which proved inefficient. The more these sealing materials wore, the more they leaked.

 

In August of 1933, R.O. Monroe and L.D. Goff, in conjunction with a local mill, designed and built the first rotary joint. It was a device that eliminated the problems associated with stuffing boxes and packing glands and allowed the water or steam to be introduced in a much more economical method. A spring-loaded mechanical seal was used to prevent the fluid or gas medium from dispersing. The secret to the rotary joint’s mechanical success was in the seal. It allowed parts of the rotary joint to rotate with the machine, while providing a leak proof seal for the fluid or gas flowing into the cylinder.

 

During the late 1930s and into the 1940s, rotary joints became the preferred method to admit fluid or gas into a rotating cylinder. Still, there were some problems associated with installation of the rotary joints. After World War II, several innovations were applied to rotary joint design. One of these was the use of flexible metal hose, which allowed the rotary joints some flexibility in movement as the seal wore. By 1946, several updates had been incorporated into the original design, and sizes were added to better accommodate the needs of the various industries requiring rotary joints.

 

By 1954, a complete redesign of the rotary joint was underway, mainly to reduce the physical size of the unit and to better accommodate the needs of specific applications. By 1957, many industries were also concerned about increasing the efficiency of heating and cooling within rotating cylinders. Kadant Johnson began a program of researching the effects of various types of syphoning devices (both rotary and stationary), and the effects of syphon clearances on the overall heat transfer from inside the rolls to the shell.

 

In 1959, a 60" x 250" (1.5 m x 6.35 m) paper dryer was converted for testing by Kadant Johnson, and actual testing of both rotary joints and various syphoning devices began in Pensacola, Florida, USA. In 1962, a research facility was set up in Three Rivers, Michigan, USA; and in 1963, the first pictures of the inside of an operating dryer were produced on 16 mm film.

 

People involved in designing and operating machines that required rotating cylinders learned a great deal about steam condensing rates and the actions within a dryer from these first films. Rotary joint technology and syphoning technology was shared with industry.

 

Through the late 1950s and into the early 1960s, this team of researchers continued to develop new designs and gather knowledge to address the needs of general industry. The need for higher operating temperatures and speeds required that the designs of rotary joints change again. Details such as quick disconnect nipples, pressure compensators, larger sizes, and longer service life were developed.

 

Into the late 1960s and early 1970s, various new seal materials, such as plastic, Teflon™, and ceramic were also tested.

 

While the early years were focused on sealing steam and water joints, today there are thousands of configurations of standard and custom rotary joints: self-supported or externally-supported; single- and dual-flow; applications using water, air, coolant, oil, molten salt, and gas; temperatures from very low to more than 1,000° F (538° C); and speeds from 1 to 50,000 RPM.

 

We are a GHP/GHPA rotary joint supplier. Please feel free to contact us if you need them!