Abrasive of the valve grinder is a mixture of abrasive, dispersant (also known as abrasive fluid) and auxiliary materials. Abrasive is used for grinding and polishing, and the abrasive particles are free when used. Because the dispersant and the auxiliary material composition and the coordination proportion are different, the abrasive has the liquid, the paste and the solid 3 kinds. Liquid abrasive can be used directly without dilution. Paste is often called grinding paste, can be used directly or add grinding fluid after the use of dilution, oil dilution called oil soluble grinding paste; Water - soluble grinding paste. Solid abrasive (grinding soap) at room temperature is lumped, can be used directly or after adding the dilution of grinding liquid. The abrasive in the abrasive plays the cutting role, the commonly used abrasive has the corundum, the silicon carbide, the boron carbide and the artificial diamond and so on. Soft abrasives, such as iron oxide, chromium oxide and cerium oxide, are also used for grinding and polishing.

Types of abrasive materials:

Alumina. Alumina, also known as corundum, has a high hardness and is widely used for grinding cast iron, copper, steel, stainless steel and other materials.

Silicon carbide (SiC). Silicon carbide has green and black, its hardness is higher than alumina. Green silicon oxide is suitable for grinding hard alloy, black silicon oxide is suitable for grinding brittle material and soft material workpiece, such as cast iron, brass, etc.

Boron carbide (B4C). The hardness is second only to diamond powder and harder than silicon carbide, which is mainly used to replace diamond powder to grind hard alloy and grind hard chromium plated surface.

Chromium oxide (Cr2O3). Chromium oxide for valve pressure test bench is a hard and very fine abrasive which is often used to polish and polish hardened steel.

Iron oxide. Iron oxide is also a very fine abrasive, but the hardness and grinding effect are worse than chromium oxide, the same use as chromium oxide.

Diamond powder. That is, crystalline carbon, it is the hardest abrasive, better cutting performance, especially suitable for grinding hard alloy.

Note: the abrasive particle size of the sealing surface is generally 120#~240#. W40~14 in fine grinding.

Modulation of abrasive, usually into the abrasive directly add kerosene and oil, with 1/3 of the kerosene and 2/3 of the oil and abrasive blend into the abrasive agent is suitable for rough grinding; With 2/3 of the kerosene and 1/3 of the oil and abrasive blend into the abrasive agent can be used for fine grinding, when the grinding hardness of the workpiece, the use of the abrasive agent effect is not ideal, can use three parts of abrasive plus a heating lard to reconcile up, after cooling to form paste, use some kerosene or gasoline to adjust evenly.