Graphite packing for thermal power plants

Graphite packing for thermal power plants

Graphite packing is mainly made of various reinforced fibers, metal wires (steel wire, copper wire, nickel wire) and other reinforced graphite wires as raw materials, which are finely woven. Suitable for static sealing under high temperature and high pressure conditions. Except for a few strong oxidants, it can be used to seal media such as hot water, superheated steam, heat transfer fluids, hydrocarbons, low-temperature liquids, etc. It is also a universal sealing gasket.
There are many segmented products of graphite packing: expanded graphite packing, flexible graphite packing, nickel wire graphite packing, stainless steel wire graphite packing, high temperature resistant packing, high temperature and high pressure graphite packing, etc···
Application of graphite packing:
Graphite packing is used for sealing valves in industrial fields such as petroleum, power plants, chemical, steel plants, etc., as a sealing medium for hot water, high-temperature, high-pressure steam, heat exchange media, hydrogen, ammonia, * * *, hydrocarbons, low-temperature liquids, etc., outside of a few strongly oxidizing media.
Graphite roots are fully immersed in special lubricating oil and woven into a square shape. The outstanding advantages are extremely low friction coefficient, no shaft wear, corrosion resistance, and can be applied in the shipbuilding industry, cold water treatment, seawater, and cold oil; Low pressure valves, rotating equipment, reciprocating pump hydraulic presses, ship propellers and other equipment are suitable for various water quality, seawater, saltwater, oil, lipid, weak acid, weak alkali and other media. When cutting the packing of the packing, the cutting angle should be roughly selected between 30 ° and 45 °. The selection of the cutting angle of the packing should be appropriately reduced within the cutting range (0 ° to 90 °), and the length of the cutting joint surface should be increased as much as possible to prolong the leakage path of the medium and enhance the sealing effect. However, if the cutting angle is too small, it is often easy to damage the sharp angle of the packing during cutting. Therefore, the cutting angle of the packing is usually selected between 30 ° and 45 °, and attention should be paid to the joint method of the packing section. The packing should be cut to the appropriate length and pressed into the packing chamber one by one. It is not allowed to continuously wrap or place the packing together for multiple turns before pressing.
With the continuous emergence of new materials, the structural types of fillers have also undergone significant changes, which will undoubtedly promote the wider application of filler seals. Materials used as fillers should have the following characteristics: a certain degree of elastic-plastic deformation. When the packing is subjected to axial compression, it can generate a significant radial compression force to achieve sealing; When there is vibration between the machine and the shaft, or when the shaft has jumping or eccentricity, it can have a certain compensation ability (followability); Chemical stability. Not corroded or swollen by the medium, nor does it contaminate the medium; Impermeability.
1. Especially suitable for various installations in high temperature, high pressure and harsh environments
2. Applied to media other than strong acids, strong bases, and strong oxidants.
3. Especially suitable for working conditions under high temperature and pressure.
4. Long service life,effectiveImproved work efficiency and reduced maintenance time.
Technical parameters of graphite packing:
Pressure: Rotary pump 2.5MPa, reciprocating pump 10MPa, valve 15MPa
Temperature: 350 ℃
PH value: 1-13
Linear velocity: 15m/s
Installation of graphite packing:
1. Install one packing ring at a time, ensuring that each packing ring is free from dust or other debris. If necessary, clean lubricating oil should be applied to the packing ring, shaft or valve stem for lubrication. When multiple rings are used, they should be installed in a staggered manner, with the notches of each disk offset by 90 degrees. When installing the ring, it should be slowly pulled apart in the axial direction, with a radial distance that allows the ring to be installed on the shaft. Use filling tools to tighten each packing ring. After the installation of sufficient packing rings is completed, seal them with follower components, which can increase the tightness. The follower is only used as a supplement to ensure the proper position of all packing rings and avoid the movement of the packing.
In reciprocating pumps, guide rings should be placed at both ends and in the middle of the packing box to maintain its concentric motion and withstand the weight of the plunger.
3. After installing the packing ring, tighten the bolts. To achieve consistent pressure on each nut, it is recommended to tighten the nut with a wrench or related measuring device. Please note: If the device is in a leak free state at this time, it may cause burning of the packing. It is recommended to turn on the water pump and slowly tighten the bolts until the leakage reaches the allowable range.
4. Start up of rotary and reciprocating pumps
1) Before operation, operate under no-load condition and observe for any abnormal conditions. Then, start the vehicle and carefully observe for any serious damage or burning of the packing caused by insufficient or too tight pressure.
2) After installing the packing ring, tighten the bolts and confirm that the material cover is correctly connected to the packing box surface. Once the bolts are tightened, ensure that each bolt is evenly stressed.
3) If an external lubrication system (cooling water flushing) is applied, it should be ensured that it can operate normally before starting.
4) Allow high * * leakage during startup, and during this process, simply confirm that the disk root is installed properly and begins to function.
5) After running for about 15-30 minutes, tighten the bolts multiple times until * * reaches the range, with a leakage rate of 18-30 points per minute.
Preparation before installation of graphite packing:
1. Removing old packing and inspecting the packing box is a key aspect of early installation preparation.
2. Before adding packing, remove all the old packing with tools and clean the packing box.
3. Observe whether there are defects such as damage, eccentricity, etc. in various parts of the packing box. Damaged valve stems, shaft sleeves, and packing boxes can all affect the performance of the packing.
4. Check if other components are still applicable. Replace all damaged components.
5. Adjust whether the bearings are concentric. If they are not concentric, they need to be adjusted or replaced.
6. Check if the water pump or mixing kettle is vibrating and adjust it to a stable operating state.

Graphite packing for thermal power plants