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| Five valves leaked technical methods should |
| Five valves leaked technical methods should |
1, valve body and valve cover leaks:
Reason:
1. High quality cast iron castings, valve and valve cover body trachoma, loosely organized, slag and other defects
2. Cold Donglie;
3. Welding bad, there are slag, not welded, stress cracks and other defects;
4. Cast iron valve damage after impact by a heavy object.
Maintenance Methods:
1. To improve casting quality, pre-installation in strict accordance with the provisions of strength test;
2. On the temperature at 0 ° and 0 ° below the valve, should be mixed with thermal insulation or heat, to stop using the water valve should be excluded
3. Formed by the welding body and the bonnet of the weld, the welding operation procedures should be carried out, testing should be performed after welding and strength testing;
4. Valves pushed up against heavy objects, do not allow hand-cast iron and non-metallic hammer hit the valve, the installation of large diameter valves should stand.
Second, the disclosure of padding (valve leakage, padding the largest proportion)
Reason:
1. Filling, right, intolerant media corrosion, high pressure or vacuum valves impatience, high or low temperature use;
2. Filler installed wrong, there is a small generation of big, bad spiral coil connector, tighten the defects such as under the loose;
3. Over the use of fillers has been aging, loss of elasticity
4. Stem accuracy is not high, there is bending, corrosion, wear and other defects
5. Packing ring less than, no compression gland;
6. Gland, bolts, and other parts damaged, so no compression gland;
7. Improper operation, excessive force, etc.;
8. Gland skew, the gap between the gland and the stem is too small or too large, causing the valve stem wear, packing damaged.
Maintenance Methods:
1. Working conditions should be selected and the type of packing materials;
2. The correct installation in accordance with relevant provisions of the packing, packing ring should be placed by compression, into the joint should be 30 ℃ or 45 ℃;
3. The use of long, aging, damaged packing should be replaced;
4. Stem bending, straightening should be carried out after wear and tear, repair of severely damaged should be replaced;
5. The number of cycles should be required to fill installation, gland response said evenly to tight, pressure sets the preload should be more than 5mm gap;
6. Damage to the gland, bolts and other components, should be promptly repaired or replaced;
7. Operational procedures to be followed, in addition to percussive hand wheel, the power to uniform normal operation;
8. Should be symmetrically cover bolt tightening squeeze, gland and stem gap is too small, should be increased, the gap; gland and valve clearance is too large and should be replaced.
3, sealing surface leakage
Reason:
1, the sealing surface uneven ground, can not form a seal line;
2, the stem and the closure of the junction of the top pieces of heart left vacant, straight, or wear;
3, stem bending or assembly is not correct, or not to shut down every piece of skew;
4, the quality of sealing surfaces use improper or no use valve according to working conditions
Maintenance Methods:
1, according to Britain the correct selection of work conditions and type of gasket material;
2, well-adjusted, stable operation;
3, should tighten the bolts evenly, if necessary using the torque wrench, tightening force should meet the requirements, not too big or small. Flange and threaded joints should be a certain preload gap;
4, gasket assembly should be closed on the positive and balanced force, and lap pads are not allowed to use double gasket;
5, static sealing surface corrosion, damage processing, processing quality, and should be repaired, grinding, for color inspection, static sealing surface to meet the requirements;
6, installation of gaskets should pay attention to cleaning, sealing surface application of kerosene clear, not landing pad.
4, seal leak link Office
Reason:
1, ring rolling strict
2, seals and body welding, surfacing of poor quality;
3, ring connecting thread, screw, loop loose;
4, ring connection and corrosion.
Maintenance Methods:
1 Department seal leakage should inject adhesive rolling again rolling fixed;
2, seal welding norms should be applied to re-understand the repair welding. Department can not repair welding welding Welding and machining should be cleared of the original;
3, remove the screw, loop cleaning, replacement of defective parts, ground sealing and connecting seat seal surface, re-assembly. Corrosion damage on a large large part, can be welding, bonding and other methods of repair;
4, ring joint face is corrosion, can be abrasive, adhesive and other methods of repair, no repair should be replaced with a ring.
5, closing off the leakage cases:
Reason:
1, operation undesirable to close the pieces stuck on dead center or more, damage to fracture junction;
2 pieces of connection is not firmly closed, slack and fall off;
3, used to connect pieces of material does not, can not withstand the corrosive medium and mechanical wear.
Maintenance Methods:
1, correct operation, close the valve can not be too hard to open the valve can not exceed the upper dead point, the valve open and then a little hand wheel should be reversed;
2, closed cases should be firmly connected with the valve stem, screw joints should only return documents;
3, closing parts and fasteners used to connect the valve stem should withstand the corrosive medium, and a certain mechanical strength and wear resistance. |
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ICP: 06003029