Regarding oil-free black PTFE packing, it reduces material consumption and increases service life. Packing seals are designed to allow a certain degree of leakage. Therefore, packing rings cannot meet all requirements in applications where定型机 (I assume you mean "textile finishing machines") operate at high speeds, sealing requirements are strict, and long service life is necessary. Due to damage to the outer layer of aramid fibers, the internal carbon fibers are squeezed between the shaft and the lower layer as the shaft rotates, leading to increased friction, increased current, and ultimately machine shutdown.
The packing rings of flexible graphite metal spiral wound gaskets are generally made of soft strip materials, which are then filled into the sealing chamber with a square cross-section to achieve a sealing effect for pumps. The sealing principle of packing seals mainly lies in the bearing and sealing functions. In earlier times, fibrous materials such as hemp and cotton were inserted into leakage channels to prevent fluid leakage.
The packing material for graphite metal spiral wound gaskets is widely available, easy to process, very inexpensive, and simple to operate. Therefore, it is widely used in shaft seals for various centrifugal pumps and vacuum pumps. Beryllium-hemp packing/oil-free black PTFE packing ensures quality by checking that no water flows out of each drain valve; checking that the local water level gauge of the high-pressure heater indicates no water level; and checking that the current and rotational speed of the feed water pump in operation do not show an upward trend and match the feed water volume and steam flow rate.
Identification of packing rings of different types of graphite metal spiral wound gaskets: The core of the high-pressure heater does not leak. Pressure exists at the upper part of the inlet combined valve, pressing down on the combined valve. The combined valve is a four-way valve. When the combined valve is closed and water exists in the bypass pipeline of the combined valve, pressure forms at the upper part of the combined valve, making it difficult to lift the valve. The bypass of the combined valve is not released. Identification: There is no water at the upper end of the inlet combined valve, which does not affect lifting the combined valve.
During the protective action of the high-pressure heater, the combined valve is pressed down, or the piston at the upper end of the combined valve used for protection jams. During the operation of the high-pressure heaters, when the water level in the steam side of any high-pressure heater, including the steam cooler and drain cooler, rises to "high-level III at 1200mm," the protective action of the high-pressure heaters presses down the combined valve and closes the steam extraction valves of the three high-pressure heaters, removing all steam and water sides of the high-pressure heaters. Verify one by one that the local water level gauges of each high-pressure heater indicate no water level.
