Skip to main content

Posts

Showing posts from September, 2015

Gate Valve

A Gate Valve is also know as Sluice Valve, is a valve that opens by lifting a round or rectangular gate/ wedge out of the path of the fluid.

Gate valves are primarily designed to start or stop flow, and when a straight-line flow of fluid and minimum flow restriction are needed. In service, these valves generally are either fully open or fully closed.
Construction of a Gate ValveGate valves consists of three main parts: body, bonnet, and trim. The body is generally connected to other equipment by means of flanged, screwed or welded connections. The bonnet, which containing the moving parts, is attached to the body, usually with bolts, to permit maintenance. The valve trim consists of the stem, the gate, the disc or wedge and the seat rings.


Discs of Gate Valve
Gate valves are available with different disks or wedges.
The most common types of Discs are :
Solid Wedges Solid wedge is the most commonly used disk by its simplicity and strength. A valve with this type of wedge can be installed in e…

Piping Dimensions (DN Vs NPS)

The size of pipes, fittings, flanges and valves are given in two Units NPS = Nominal Pipe Size (Inches) DN = Diameter Nominal (Metric)
Following is the comparison :
Diameter Nominal
DN
(mm)
Nominal Pipe Size
NPS
(inches)
6 1/8 8 1/4 10 3/8 15 1/2 20 3/4 25 1

Valve Fundamentales

valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.
They perform any of the following functions. Starting and stopping or isolating fluid flow. In an open valve, fluid flows in a direction from higher pressure to lower pressure. Controlling or varying (throttling) the amount of fluid flow by change of direction or restriction. Checking the flow or controlling the direction of fluid flow and preventing backflow.Regulating downstream system or process pressure.Relieving component or piping system of a certain pressure.
The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll.
Valves may be operated manually, either by a handle, lever, pedal or wheel. Valves may also be automatic, driven by changes in pressure, temperature, or flow. These changes may act upon a diaphragm or a piston which in turn activates …