The assembled pneumatic ball valve cannot be sealed. In order to ensure that there is no leakage during the assembly of metal sealed pneumatic ball valve, the plating layer shall be 0.03ram. After electroplating, the ball shall be reground to remove excess metal and ensure the roundness of the ball. The roundness and roughness of the sphere processed by this method meet the requirements of the drawing. Comply with API inspection standards. If the grinding device reformed from the power head is matched with the spherical lathe to form a combined turning, grinding and grinding machine tool, it is completely possible to realize the gas sealing of the metal sealed pneumatic ball valve. Generally, three jaw chuck or four jaw chuck clamping method is used to process the 90 degree sealing surface of the valve seat. The workpiece processed by this method has more turning at the jaw, which makes the workpiece out of round at many points. Thus, process the valve seat 90. The method of pressing shall be adopted for the conical surface. When finishing the final turning, loosen the pressing plate and press it gently again. After the valve seat is machined, the valve seat shall be lapped by the method of ball and valve seat lapping to improve the roughness (R4o. 8Fro) and the roundness of 9O cone surface, so that the sealing between the ball and the valve seat will not leak. When fixing the seal, the pre compression is 0.25d (d is the diameter of the rubber strip of the O-ring). For sliding seal, the pre compression shrinkage is 0.15d. In the fixed ball pneumatic ball valve, the preload of the O-ring shall be calculated by connecting the sliding seal 0.15d. However, at present, the O-ring pre compression of the fixed ball pneumatic ball valve is too large. Pneumatic ball valve is a kind of valve with higher processing and assembly requirements, and the processing precision of fixed pneumatic ball valve is required to be higher. Only by constantly summarizing the experience of the production process and exploring more scientific and innovative methods can we produce high-quality, high-level fixed pneumatic ball valves.

The non-metallic compensator is an important part of the circulating fluidized bed boiler. The quality of its device directly affects the sealing of the circulating fluidized bed boiler, and then affects the safe and stable operation of the boiler. Therefore, it is very important to study the non-metallic contraction joint device.
1. Structure and function of non-metallic contraction joint: non-metallic contraction joint, also known as non-metallic compensator, is mainly used to absorb the relative displacement of two components with relative displacement and seal the connection channel between two components with relative displacement.
The non-metallic compensator is composed of non-metallic skin, thermal insulation parts, metal flanges, rib plates, bolts and stainless steel mesh, ceramic fiber rope or pillow shaped sealing materials, etc. The skin is made of heat resistant rubber and glass cloth. The internal structures of non-metallic contraction joints at different parts are different. For example, there is a layer of polytetrafluoroethylene insulation film on the inner side of the skin. The insulation quilt is composed of aluminum silicate refractory fiber felt or rock wool wrapped with ceramic fiber cloth at the insulation part, and the insulation quilt is composed of aluminum silicate refractory fiber felt wrapped with glass ceramic fiber cloth at the insulation part.
The three-dimensional contraction direction of non-metallic contraction joints varies with the working position of non-metallic contraction joints. The design fatigue life of non-metallic contraction joints is generally 3000 times. The service life of the advanced non-metallic contraction joint is closely related to the seal design structure selected on the flue gas side of the furnace in addition to the selected data, which has been proved on the operating boiler.
2. Inspection before operation of non-metallic compensator: after the completion of the boiler device and before the commissioning of individual parts, a comprehensive inspection of non-metallic contraction joints should be stopped, mainly to check whether the temporary support and fixing parts can be removed, otherwise the normal displacement of non-metallic contraction joints will be affected.
Check whether the pillow seal data and skin inside the non-metallic compensator furnace are intact, to prevent high-temperature flue gas from flowing from inside to outside and burning non-metallic contraction joints. Check whether the non-metallic sealing gasket and bolt installed on the manhole door above the non-metallic contraction joint can be tightened and sealed tightly, so as to avoid the leakage of high-temperature materials from the sealing surface of each hole door to the outer skin of the non-metallic contraction joint and damage the outer skin of the non-metallic contraction joint. When there is no problem in the inspection, it can cooperate with the boiler host to stop the divisional test run.