A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints. Cement ball mill rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls. An internal cascading effect reduces the material to a fine powder. Industrial ball mills can operate continuously, fed at one end and discharged at the other end. Large to medium-sized ball mills are mechanically rotated on their axis, but small ones normally consist of a cylindrical capped container that sits on two drive shafts (pulleys and belts are used to transmit rotary motion). A rock tumbler functions on the same principle. Ball mill manufacturers are also used in pyrotechnics and the manufacture of black powder, but cannot be used in the preparation of some pyrotechnic mixtures such as flash Valve fittings powder because of their sensitivity to impact. High-quality ball mills are potentially expensive and can grind mixture particles to as small as 5 nm, enormously increasing surface area and reaction rates. The grinding works on the principle of critical speed. The critical speed can be understood as that speed after which the steel balls (which are responsible for the grinding of particles) start rotating along the direction of the cylindrical device; thus causing no further grinding.

The ball mill is a key piece of equipment for grinding crushed materials, and it is widely used in production lines for powders such as cement, silicates, refractory material, fertilizer, glass ceramics, etc. as well as for ore dressing of both ferrous non-ferrous metals. The ball mill can grind various ores and other materials either wet or dry. There are two kinds of ball mill, grate type and overfall type due to different ways of discharging material. There are many wet ball mill suitable Double Union Diaphragm Valve for use in a ball mill, each material having its own specific properties and advantages. Key properties of grinding media are size, density, hardness, and composition.

Aside from common ball mills there is a second type of ball mill called Planetary Ball Mill. Planetary ball mills are smaller than common ball mills and mainly used in laboratories for grinding sample material down to very small sizes. A used ball mills consists of at least one grinding jar which is arranged eccentrically on a so-called sun wheel. The direction of movement of the sun wheel is opposite to that of the grinding jars (ratio: 1:-2 or 1:-1 or else). The grinding balls in the grinding jars are subjected to superimposed rotational movements, the so-called Coriolis forces. The difference in speeds between the balls and grinding jars produces an interaction between frictional and impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill.

Gate valve, which is also known as knife valve or slide, is basically used to control the flow of water or any kind of liquid through a pipe or duct. When these valves are turned a closure element moves up and down to obstruct the flow of liquid. It is widely used in many places including homes, factories, large industries, hotels and so forth.

Due to the widespread uses and advantages of gate valve, it can be found in different varieties to suit the different requirements. Some of the most popular varieties include the following.Parallel valves: These valves control the flow of liquid by utilising a flat disc that is placed between two parallel seats. These two seats are placed in an upstream and downstream manner. This can be used effectively to control the flow of water. Wedge valves: The wedge gate valve is one of the most popular varieties of valves. It has a misaligned gate and two inclined seats.

Rising stem valves: This is the most common variety of valve used in most of the areas today. It has a round handle which is attached to a shaft or stem. This shaft rises as the handle is turned, to open the valve. The shaft CPVC Pipe comes down when the valve is closed. Though it is one of the most popular types of valves, it cannot be used in areas where there is space constraint.

Non-rising stem valves: This gate valve is popularly used for underground pipes where it is difficult for the shaft to raise. The valve can be opened by rotating the handle to the left and closed by rotating it fully to the right. It is quite easy to padlock the non-rising stem valves compared CPVC Pipe to the rising stem valves. The non-rising stem valves require only one paddock unlike the rising stem valves which require two paddocks.

Though the basic function of these valves is to control the flow of liquid, it can seldom be used to regulate the flow of liquid in a continuous manner. It is usually used to completely shut down or open the duct. Most of the valves are designed specifically to allow free flow of liquid or to shut down the flow completely. However, there are valves which can be utilised to regulate the flow of liquid but it operates in a more complex manner and seldom lasts longer.These valves are more often used to control the flow of liquids which are thicker in consistency such as cream, oil and so forth. Nevertheless, it can seldom be utilised for controlling the flow of clean liquids.