Carbon Steel WCB Globe Manual Valve with RF Flanged Connection
|Design and Manufacture||Cast steel globe valve to BS 1873 and ASME B16.34;Forged steel
globe valve to API 602.|
|Inspection and Test||API 598|
|End flange dimension||ASME B16.5|
|BW end dimension||ASME B16.25|
|Socket-weld dimention||ASME B16.11|
|Face to Face and end to end||ASME B16.10|
|Pressure temperture ratings||ASME B16.34|
A globe valve, different from ball valve, is a type of valve used for regulating
flow in a pipeline, consisting of a movable disk-type element and a
stationary ring seat in a generally spherical body.
Globe valves are named for their spherical body shape with the two
halves of the body being separated by an internal baffle . This has an opening that
forms a seat onto which a movable plug can be screwed in to close (or shut) the valve. The plug is also
called a disc or disk. In globe valves, the plug is connected to a stem which is operated by screw action using a handwheel in manual
valves. Typically, automated globe valves use smooth stems rather
than threaded and are opened and closed by an actuator assembly.
Although globe valves in the past had the spherical bodies which
gave them their name, many modern globe valves do not have much of
a spherical shape. However, the term globe valve is still often used for valves that have such an internal
mechanism. In plumbing , valves with such a mechanism are also
often called stop valves since they don't have the global appearance, but the term stop valve may refer to valves which are used to stop flow even when they
have other mechanisms or designs.
Globe valves are used for applications requiring throttling and
frequent operation. For example, globe valves or valves with a
similar mechanism may be used as sampling valves, which are
normally when liquid samples are being taken. Since the baffle
restricts flow, they are not recommended where full, unobstructed
flow is required.
Globe valves are always reverse seated.
Carbon steel globe valve. Valves and are generally made of plastic or steel, the latter
being the most widely used in chemical and petrochemical
applications. Steel grades range from the most common type, namely
carbon steel, with standard stainless steel being the second most
common. Stainless steel alloys, which include nickel or copper are
used in applications that require higher corrosion or heat
resistance. In such cases, the most commonly used valve
configurations -- ball valves, gate valves, check valves, globe
valves and butterfly valves -- are often forged or cast as duplex
valves, super duplex valves, alloy 20 valves, monel valves, inconel
valves, incoloy valves and 254 SMO valves (6Mo valves). Titanium
valves are also used in some highly corrosive applications.
Titanium is not a stainless steel alloy.
The body is the main pressure containing structure of the valve and
the most easily identified as it forms the mass of the valve. It
contains all of the valve's internal parts that will come in
contact with the substance being controlled by the valve. The
bonnet is connected to the body and provides the containment of the
fluid,gas, or slurry that is being controlled.
Globe valves are typically two-port valves, although three port
valves are also produced mostly in straight-flow configuration. Ports are openings in the body for fluid flowing in or out. The two
ports may be oriented straight across from each other or anywhere
on the body,or oriented at an angle (such as a 90°).Globe valves
with ports at such an angle are called angle globe valves. Globe
valves are mainly used for corrosive or high viscous fluids which
solidify at room temperature. This is because straight valves are
designed so that the outlet pipe is in line with the inlet pipe and
the fluid has a good chance of staying there in the case of
horizontal piping. In the case of angle valves, the outlet pipe is
directed towards the bottom. This allows the fluid to drain off. In
turn, this prevents clogging and/or corrosion of the valve
components over a period of time. A globe valve can also have a
body in the shape of a "Y". This will allow the construction of the
valve to be straight at the bottom as opposed to the conventional
pot type construction (to arrange bottom seat) in case of other
valves. This will again allow the fluid to pass through without
difficulty and minimizes fluid clogging/corrosion in the long term.