Valve For Plant Industry

Valve is a tool to regulate the flow of a fluid with closed, open or block a portion of the flow path. Examples are easy to tap water. Obligation for a pipeline engineer to know at least the basics of this valve.
Some kind of valve is often used is as follows.

1. Gate Valve
Form of insulation is a disc, or often called a wedge, driven into the bottom to open and close. Used to open or close a position perfect and not recommended for most positions open.

2. Globe Valve
Usually used to adjust the amount of fluid flow.

3. Butterfly Valve
Form of insulation is a dish that has a pivot in the middle. According to its design, can be divided into concentric and eccentric. Eccentric has a design that is more difficult but has a better function than concentric. A simple shape makes lighter than any other valve.

4. Ball Valve
Insulation forms a ball-shaped hole through the middle.

5. Plug Valve
Like the ball valve, but the inside is not spherical, but cylindrical. Because there is no empty space inside the valve body, it is suitable for the heavy fluid or solid element such as mud.

6. Check Valve or Non-Return Valve
Has a function for fluid flow in only one direction and prevent flow in the opposite direction. Have some type of longer based on the inside like a double-plate, swing, tilting, and axial.

Of the various types of valves above, what basis and how to determine the valve to be used?

First we see is a function. Valve that will only be used to open or close the position perfectly, gate, butterfly, ball or plug can be used. If the valve will be used to adjust the amount of flow (used in conditions between open and closed) then the globe valve is the most appropriate. Different if the required function is to prevent the backflow, the check valve is the only choice.

After that we see from its size. Ball, plug, or globe valve, suitable for small size, but for large size valves will be very heavy, ineffective and not economical. Replace the butterfly valve is a common path taken for the large valve. But it should be noted also that the butterfly valve is not normally used for high-pressure fluid.

So how do I choose between the gate and ball valve which both have the same function? The structure of the ball valve better use of soft / resilient seat for the partition. With soft seat, the ball valve can be made to guarantee zero leakage that can not be applied to the gate valve. In addition, the ball valve also has a quarter turn system that allows closing and opening the valve quickly. But the weakness of soft seats that are vulnerable to high temperature, gate valve has the advantage with a lighter weight and more economical, although not guarantee zero leakage.
This is an engineer required pipe capacity can consider various things in deciding which valve should be used. In the face of such a thing, usually an engineer will consider the lessons learned from previous designs, both from his own experience and from the data available. The following table is an example of the handle to select the appropriate valve.