Manual Valves

V-Flow Solutions can offer a wide range of manual valves including: Ball, butterfly, gate, globe and diaphragm. These valves can be manual, plastic or even actuated.

In this blog we look at each of these types of valves.

Ball valve

A ball valve is a form of quarter turn valve which uses a hollow, perforated and pivoting ball valve to control flow through the valve. 
Ball valves are durable and reliable, shown by their ability to maintain the same quality and efficiency even after multiple uses. The reliability can be seen through the ability to operate as new even after long periods of disuse.

Other qualities of ball valves are their ease of operation, repair and how versatile they are, this versatility meaning they are used throughout a wide range of industrial applications.

Ball valves are available in a variety of materials and can be supplied as manual, actuated or plastic.

V-Flow Solutions offer a range of manual ball valves capable of: 

Working temperature: -25 to +200°C

Working pressure: 16 - 82 Bar

Size: 1/4" - 4"

You can view the V-Flow Solutions range of ball valves here:

http://v-flowsolutions.co.uk/manual-valves/ball/

Butterfly valve

The operation of a butterfly valve is similar to a ball valve and allows for quick shut off.

Butterfly valves may be favoured because of their low cost and lighter weight.

The butterfly is a metal disk mounted on a rod. Just like a ball valve, the butterfly valve can be opened incrementally to throttle flow. 

When the valve is closed the disk is turned to completely block off the flow.

When the valve is fully open, the disk is rotated a quarter turn so that it allows almost unrestricted flow to pass through.
Unlike a ball valve, the disk of a butterfly valve is always present, so it induces a pressure drop, even when open.

Butterfly valves have different variations, each one being adapted for different pressures and usage.

• The zero offset butterfly valve has the lowest pressure rating.
• The double offset butterfly valve, which is used in slightly higher-pressure systems, it is offset from the centre line of the disk seat and body seal, and the centre line of the bore.
• The triple offset butterfly valve is the best suited for high pressure systems.

V-Flow Solutions offers a range of manual Butterfly valves capable of:

Working temperature: -20 to +110°C

Working pressure: 7 - 16 Bar 

Size: 2" to 24"

You can view the V-Flow Solutions range of Butterfly valves here:

http://v-flowsolutions.co.uk/manual-valves/butterfly/

Gate valve

A gate valve operates by lifting a round or rectangular gate/wedge out of the flow path.

The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when the straight-line flow of fluid and minimum restriction is required.

The gate faces can be parallel, but are most commonly wedge shaped.

Gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldn’t be used for regulating flow unless specifically designed for this purpose.

Because of the ability to cut through liquids, gate valves are typically used in the petroleum industry.

For extremely thick fluids, a speciality gate valve; a knife gate valve, is used to cut through the liquid.

Typical gate valves are designed to be fully opened or closed. When fully open the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.

Globe valve

A globe valve, different from a ball valve, is used for regulating flow in a pipeline, consisting of a movable disk-type element and a stationary ring seat in a spherical body.

The spherical body shape provides the name for the valve, with the two halves of the body being separated by an internal baffle. This has an opening that forms a seat onto which a moveable plug can be screwed in to close (or shut) the valve. The plug is called a disk. In globe valves, the plug is connected to a stem which is operated by screw action using a handwheel in manual valves.

Many modern globe valves do not have a spherical body but still use the same name.

There are valves used in plumbing that use the same mechanism, without the spherical body and these are referred to as stop valves.

Diaphragm valves

Diaphragm valves consist of a valve body with two or more ports, a diaphragm and a weir or saddle, seat upon which the diaphragm closes the valve. 
The valve is constructed from either plastic or metal.

One type of diaphragm valve is where the seal forms over a saddle, which is the most common in process applications.
The other type of diaphragm valve, where the seal forms over the seat (this is sometimes called a "full-bore or straight-way" valve).

Diaphragm valves can come in both 2/2 or 3/2 way configurations. The 3/2 way diaphragm valves are also called t-valves, there are also other configurations called block valves.
When more than three ports are included, they generally require more than one diaphragm seat however; special dual valves can handle more ports with one membrane.
Their applications are generally as shut-off valves in process systems within the industrial, food and beverage, pharmaceutical and biotech industries.

Diaphragm valves can be manual or actuated.

In addition to the well-known, two way shut off diaphragm valve, other types include: three way zero dead leg valve, sterile access port, block and breed, val bow and tank bottom valve.

You can read the rest of V-Flows blogs here.