1 See if the specifications are suitable Most agricultural spare 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 purchase the drive belt, you should pay attention to the model and the perimeter; when choosing the bearings, pay attention to the bearing category; When you pay attention to the zero taper angle and the diameter of the injection hole, when you purchase the piston and piston ring, you should distinguish between the standard size and the increased size, so as to avoid erroneous losses caused by the wrong purchase.
2 See if the logo is complete The quality of the authentic packaging is good, the writing on the packaging is clear, and the color of the logo is clear. The packing box and box shall be marked with the product name, specification, model, quantity, registered trademark, factory name and telephone number, etc. Some manufacturers also put their own marks on the accessories, and some large or important parts With instructions for use to guide the user to use and maintain properly. Should be recognized when purchasing, to prevent fake and shoddy products.
3 See if there are deformations in geometric dimensions Some parts are prone to deformation due to improper manufacturing, transportation, and storage. During inspection, whether the shaft parts along the glass plate with or without light leakage to judge whether to bend; optional clutch driven plate steel or friction plate, the steel plate, friction plate can be observed in front of the warpage When selecting the oil seal, the end face of the oil seal with the skeleton should be perfectly round, and it can be attached to the flat glass without flexing; the outer edge of the non-skeletal oil seal should be upright, and it should be deformed by hand to restore the original state after loosening the hand. When purchasing various kinds of pads, you should also pay attention to check the geometric shape.
4 See if the joint is flat or not. During the handling and storage of parts, due to vibrations and bumps, burrs, indentations, breakages, or cracks often occur, affecting the use of parts.
5 See whether the surface of parts has rust-qualified parts surface, both with certain precision and bright finish. The more important the spare parts, the higher the finish, the more rigorous and anti-corrosion on the packaging. Should pay attention to inspection when purchasing, if found parts of rusty 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. For example, the piston pin and the bearing shell are protected with paraffin; the surface of the piston ring and cylinder liner is coated with anti-rust oil and wrapped with wrapping paper; the plunger pair and the outlet valve pair Immersion rust-proof oils such as needle valves, etc. are sealed with plastic sleeves; valves, pistons and other impregnated rust-proof oils are sealed in plastic bags. If it is found that the sealing sleeve is damaged or the wrapping paper is missing during the purchase, the rust-proof oil or paraffin is lost and should be returned.
7 See if the glued parts have loose parts that are composed of two or more parts. The parts are pressed, glued or welded, and loosening between them is not allowed, such as the plunger and adjustment of the oil pump. The arm is assembled by press-fitting; the clutch driven jaw and the steel plate are riveted together; the friction plate and the steel plate are riveted or glued together; the paper filter core skeleton and the filter paper are glued together; The thread is welded. If it is found to be loose during purchase, it should be exchanged.
8 To see if the rotating parts are flexible to choose the oil pump and the 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 be on the column when toggling the adjustment arm. When the plug sleeve rotates flexibly, when the roller is pushed, the plunger should be able to automatically return under the action of the spring; when choosing the flow bearing, one hand supports the shaft inner ring, the other hand rotates the outer ring, and the outer ring should be able to rotate quickly and freely. Then gradually stop. 9 See if there are missing parts in the assembly parts When selecting the injector assembly, check whether there are any missing parts such as the sealed copper mat of the oil return joint, the small steel ball in the tappet, etc. When selecting the fuel injection pump assembly, Check whether the small parts such as the plunger sleeve locating screw gasket and the wheel body positioning pins are missing.
10 See if the assembly mark is clear to protect the device relationship of the fittings to meet the technical requirements, and the assembly marks are engraved on the surface of some parts. Unmarked or indistinguishable markings will cause great difficulty in assembly, often resulting in incorrect installation.
11 See if there is any wear on the mating surface. If there is any trace of wear on the mating surface of the part, or if the paint part finds the old paint after prying off the surface layer, it is mostly disused for scrap parts. At this time, it can be returned.
12 See if the surface hardness is up to the standard All the surface hardness of the mating parts have requirements. After confirming the purchase and negotiating with the merchant, the hacksaw blade can be used to test for scratches, and the scratches can be traced with high hardness. The hardness of the shallow mark is high; the hardness of the visible mark after drawing is low.
Monocalcium Phosphate
Feed Grade Dcp Co., Ltd. , http://www.nsfeedgrade.com