First, the sand blasting gun and its components can be replaced and purchased by yourself
What kind of spray gun each blasting machine uses, there is no hard use rule, it seems to be a personal use habit. Of course, depending on the purpose of the blasting and the use of the sand material, you can choose a little, mainly based on the standard of achieving the blasting purpose, such as For engraving, of course, a sandblasting gun with a handle is of course good. If the nozzle is durable, of course, a sandblasting gun that can use a boron carbide nozzle is good (some spray guns use special-shaped nozzles, and boron carbide nozzles are not used).
If it is an automatic sand blasting machine, you need to consider the total cost of the air gun when replacing the spray gun to ensure the stable air supply of the air compressor. Generally speaking, the inner diameter of the core of the standard sand blasting machine is 4MM, which is a universal type. Don't worry about too many gun models.
Second, the following factors are considered when replacing the spray gun:
1) The size of the spray gun: The size and model of the spray gun are related to the internal space and fixation of the sand blasting machine, especially the automatic sand blasting machine. Generally, the manual sand blasting machine uses a small and exquisite spray gun with a large output, such as a C-type spray gun. Then you need to consider the model of the fixed gun frame to see if you choose an ear spray gun (A / B / K type) or an inlay spray gun (C type gun).
2) When buying or replacing a spray gun, you need to consider the size of the remaining blast gun spare parts in stock: for example
Problems with the ribs of the nozzle sleeve: there are thick (tooth pitch 2.0mm) and fine (tooth pitch 15mm);
The size of the outer diameter of the air core of the spray gun: A type B type core has 18mm and 17mm diameter, C type has 15mm and 16mm or other;
The size of the inner diameter of the air core of the spray gun: the standard inner diameter of the air core is 4mm, and there are special purpose inner diameters of 3 or 2 or 5mm. The corresponding inner hole of the nozzle should be different;
If you don't pay attention to the above situation, the returned spray gun and the spare parts in stock are not up to the head, or the nozzle sleeve cannot be screwed on, or the sand is not produced, or the air core cannot be inserted into the spray gun, which results in headaches.
3) Nozzle sleeve and nozzle matching problems: The nozzle is universal, and the nozzle sleeve is related to the outer diameter and length of the nozzle. Generally speaking, the outer diameter of the nozzle is 0.3mm deviation according to the national standard. The returned nozzle cannot be inserted into the nozzle sleeve. Please handle it as follows, it will definitely work:
A: Boil the rubber sleeve with boiling water. After the water is softened for about 10 minutes, you can insert it.
B: If it ’s not boiled. Go to the hardware processing shop, and ask the master to cut the inside diameter of the rubber sleeve with a machine tool. It's very fast and cheap. It costs more than ten yuan to cut 50 pieces.
Third, supplementary language:
1) The spray gun of the universal pressure siphon sand blasting machine generally uses a straight hole nozzle, because the straight hole nozzle is relatively cheap and can meet the requirements of most blasting effects.Even if the intensity of the blasting is not as large as that of the Venturi nozzle, it can also be used. Adjusted by using long nozzles and increased pressure to meet demand.
2) Venturi nozzles are usually used for pressure sandblasting machines, especially Venturi nozzles are used for sandblasting machines imported from abroad, because the purpose of using pressure sandblasting machines is to spray difficult objects in order to achieve good If you want to change the nozzle type, it is necessary, but why buy a pressure type sand blasting machine at that time, I feel like buying a bull knife to kill the chicken.
Of course, for small area blasting or special purpose blasting such as engraving, a pressure-type blasting machine must be used to achieve the pressure effect.At this time, a pressure-type small blasting gun will be used.This type of blasting gun uses a straight hole type. The nozzle with a small inner diameter is the same as the nozzle of a siphon type sand blasting machine and is economical.
3) Some nozzles have an outer diameter of 15MM, and the nozzles with a longer nozzle length of 60MM and 80MM are mostly used for mobile sand blasting machines or for convenient spraying in small areas. Generally, the common nozzle outer diameter is 20 (21) MM, the length and The inner diameter is the selection factor to consider the effect of blasting.