First, see if the specification is suitable. Most agricultural Machinery Parts have the specified model and technical parameters. If you purchase electrical equipment, you should pay attention to check whether the voltage and power of the replaced parts are the same; when you choose the drive belt, Aluminum castings you should pay attention to the model and the perimeter; when choosing the bearings, you should pay attention to the bearing category, etc., so as not to buy the wrong equipment. Caused undue losses.

Second, see if the logo is complete. Authentic products have good outer packaging quality, clear writing on the packaging box, vivid overprinting color, and on the packing box and box, they should be marked with the product name, model number, quantity, registered trademark, factory name and telephone number, etc. Put your own mark on the accessories. When large or important parts are shipped from the factory, there are also instructions for use to guide the user to use and maintain it properly. When buying, you should recognize it to prevent buying fake and shoddy products.

Third, see whether the geometric deformation. Some parts are prone to deformation due to improper manufacturing, transportation, and storage. When buying, pay attention to checking whether the geometric size and shape are qualified.

Fourth, see if the joint is flat. During the handling and storage of spare parts, due to vibrations and bumps, burrs, indentations, breakages, or cracks often occur, affecting the use of parts, and attention should be paid when selecting and purchasing.

Fifth, to see whether the surface of parts rust. Qualified parts surface, both a certain degree of precision and bright finish, the more important parts, the higher the degree of the table, the rust on the package, the more strict anti-corrosion. Should pay attention to check the purchase, if found parts of rust spots, mold spots or rubber pieces cracking, loss of elasticity, or the surface of the journal has a clear turning pattern, should be exchanged.

6. See if the protective surface is intact. Most parts are coated with a protective layer at the factory, such as piston and nitrate, and the bearing is protected by paraffin: the piston ring and cylinder liner are coated with rust-proof oil and wrapped with wrapping paper. If the sealing sleeve is found damaged and the wrapping paper is missing when it is purchased, Anti-rust oil or paraffin loss should be returned.

Seven, see if there are loose parts glued. The fittings made of two or more parts are assembled by pressing, gluing or welding. No loosening phenomenon is allowed between them. For example, the plunger of the oil pump and the adjusting arm are assembled by pressing; The clutch driven jaw and the steel plate are riveted together. The friction plate and the steel plate are riveted or glued together. If there is looseness during the purchase, they should be exchanged.

Eight, see if the rotating parts are flexible. When selecting the oil pump and hydraulic pump assembly, turn the pump shaft by hand and feel flexible and without any stagnation; when selecting the fuel injection pump assembly, the plunger should be able to rotate freely in the plunger sleeve when toggling the adjustment arm. When pushing the roller, the plunger should be able to automatically return to position under the action of the spring.

Ninth, see if there are missing parts in the assembly parts. When selecting the injector assembly, check whether there is any leakage of the small parts such as the sealed copper mat of the oil return joint and the small steel ball in the tappet; when selecting the fuel injection pump assembly, you should check the plunger sleeve locating screw seal Whether the small parts such as wheel positioning pins are missing.

Ten, see whether the assembly mark is clear. In order to protect the device relationship of the mating parts in accordance with the technical requirements, an assembly mark is engraved on the surface of some parts. Unmarked or indistinguishable markings will cause great difficulty in assembly, often resulting in incorrect installation.

Eleven, to see whether the surface wear and tear. If the parts have wear marks on the mating surface, or if paint parts find the old paint after prying off the surface paint, they are often disguised as worn-out parts and can be returned.

Twelve, to see if the surface hardness is up to standard. The surface hardness of the fittings has requirements. After the purchase is determined and agreed with the merchant, the hacksaw blade can be used to test. The hardness of the scratch is high when scratched; the hardness is slightly higher after scratching. ; There is a clear trace of the hardness of the bottom.