(2) Installation process
① Install the valve into the pipeline. Any end of the valve shall be installed at the swimming end h. The valve for handle drive can be installed at any position on the pipeline. However, the manual pneumatic ball valve with gearbox and the pneumatic pneumatic ball valve with pneumatic driver are installed vertically, that is, they are installed on the horizontal pipeline, and the driving device is above the pipeline.
② The sealing gasket shall be installed on the connecting pipe shoe between the valve flange and the pipeline flange according to the design requirements.
③ The bolts on the flange shall be symmetrically tightened one by one and evenly.
④ Connect the pneumatic pipeline when using pneumatic actuator).

Mechanical properties Its friction coefficient is very small, only 1/5 of polyethylene, which is an important feature of the appearance of perfluorocarbon. And because the intermolecular force between fluorine and carbon chain is extremely low, PTFE is not sticky.
Teflon hose PTFE adheres to excellent mechanical properties in a wide temperature range of - 196~260 ℃. One of the characteristics of perfluorocarbon polymer is that it is not brittle at low temperatures.
Chemical corrosion resistance and weather resistance Except for molten alkali metal, PTFE is hardly corroded by any chemical agent. For example, in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even boiling in aqua regia, its weight and performance have not changed, and it is almost insoluble in all solvents, only slightly soluble in total alkanes (about 0.1g/100g) above 300 ℃. Polytetrafluoroethylene is non hygroscopic, non combustible, and extremely stable to oxygen and ultraviolet rays, so it has excellent weather resistance.
Electrical properties Teflon hose The dielectric constant and dielectric loss of PTFE in a wide frequency range are very low, and the breakdown voltage, volume resistivity and arc resistance are high.
Radiation resistance The radiation resistance of polytetrafluoroethylene is poor (104 rad), which causes degradation after high energy radiation, and the electrical and mechanical properties of the polymer are significantly reduced.
Polytetrafluoroethylene is produced by radical polymerization of tetrafluoroethylene. In industry, polymerization reaction is stopped by stirring in the presence of a large amount of water to disperse reaction heat and facilitate temperature control. Polymerization usually stops at 40~80 ℃ and 3~26 kgf/cm2. Inorganic persulfate and organic peroxide can be used as initiators, and oxidation can also be used to restore the initiator system. 171.38kJ heat is released per mole of tetrafluoroethylene polymerization. Dispersion polymerization requires the addition of perfluorinated surfactant, such as perfluorooctanoic acid or its salts.
PTFE hose can be compressed or extruded; It can also be made into water dispersions for coating, impregnation or fiber making. Polytetrafluoroethylene is widely used in atomic energy, aerospace, electronics, electrical, chemical, machinery, instruments, meters, construction, textile, food and other industries as temperature resistant, corrosion resistant materials, insulation materials, anti sticking coatings, etc.