Boiler Pump Valve Parts Material Selection and Troubleshooting

Today, boiler feed pumps manufacturer to take you to learn about the boiler pump valve parts of the material applicable occasions and often encounter fault maintenance methods.
      1, the valve body, bonnet and valve often encounter fault maintenance methods
        phenomenon
        Leakage of valve body and bonnet
        the reason
        Cast iron casting quality is not high, the valve body and valve cover body with trachoma, loose tissue, slag and other defects;
        Day cold cracking;
        Poor welding, there is slag, no welding, stress cracks and other defects;
        The cast iron valve is damaged by heavy objects.
        Maintenance method
        Improve the quality of casting, before the installation in strict accordance with the provisions of strength test;
        The temperature of 0 ° and 0 ° below the valve should be insulated or mixed heat, stop the use of the valve should be excluded from the water;
        The welds of the valve body and bonnet, which are made of welding, shall be carried out in accordance with the relevant welding procedure and shall be tested and tested after welding.
        Do not allow the use of hand hammer impact cast iron and non-metallic valves, large diameter valve installation should be bracket.
        Bonding method
        The use of adhesive curing fast characteristics, in a timely manner near the pin coated with adhesive, the establishment of a new solid seal structure, to stop the purpose of leakage. It is a special function of the use of adhesives with pressure plugging a way.
        Welding method
        In the valve body leakage medium pressure is low, the leakage is small, you can use a more than twice the diameter of the leak more than the nut, so that the leakage medium from the nut out, the nut welded to the valve body, A bolt with the same specifications of the nut, the bottom of the nut placed a rubber pad or asbestos pad, the top of the bolt around the raw tape into the nut, to prevent the purpose of leakage.
        For the leakage medium pressure, leakage of large valve body, drainage welding method can be used. First with a piece of iron, the middle of the opening of a hole, a well with the hole diameter of the isolation valve welded to the iron plate on the hole, open the isolation valve, the iron plate at the central hole at the leakage point fit in the valve body, So that the leakage medium through the iron plate and the isolation valve out of the central valve.
        In the body of the leakage medium high temperature and pressure, but the adjustment valve has a larger shape and size, leakage is not the case can also be used welding method.
 2, the valve seal often encounter fault maintenance methods
        phenomenon:
        Seal at the junction of the seal
        the reason:
        The seal is not tight;
        Sealing ring and the body welding, welding quality is poor;
        Seal connection thread, screw, pressure ring loose;
        The seal is connected and corroded.
        Maintenance method:
        Sealed at the pressure of the leak should be injected with adhesive and then rolling fixed;
        Seal ring should be re-welding according to welding specifications, welding can not repair welding should be removed when the original welding and processing;
        Remove the screws, press the ring to clean, replace the damaged parts, grind the seal and connect the seat seal, reassemble. Corrosion damage to the larger parts, welding, bonding and other methods can be used to repair;
        Seal connection surface is corroded, can be used grinding, bonding and other methods to repair, can not be repaired when the seal should be replaced.
3 valve stem often encounter fault maintenance methods
        phenomenon
        Stem is not flexible
        the reason
        Stem with it with the processing of low precision, with the gap is too small;
        Stem, stem nut, bracket, gland, packing and other axes are not in a straight line;
        Packing pressure too tight;
        Stem bent, damaged;
        Thread is not clean or rusty, poor lubrication conditions;
        Nut loose, thread slip wire;
        The stem is loose or damaged at the connection to the drive.
        Maintenance method:
        Improve the valve stem, stem nuts and other processing accuracy and repair quality, so that the gap should be appropriate;
        When assembling the stem and its connection, the gap is consistent, keep concentric, flexible rotation;
        Packing pressure too tight, the appropriate relaxation gland;
        Stem bending should be corrected, for those who are difficult to correct, should be replaced. When operating the stem, the closing force is appropriate;
        Stem, stem nut thread should always be cleaned and add lubricants, high temperature valves, should be coated with disulfide pins or graphite powder for lubrication;
        Stem nut loose should be repaired, can not repair the timely replacement;
        So that the nuts at the oil flow, lubrication is good, do not often operate the valve, regular inspection and activities about the stem, found that wear and bite the phenomenon of timely repair stem nuts, brackets and other accessories;
        To properly operate the valve, the closing force to be appropriate, so as not to deformation and damage to the valve stem;
        After closing, the valve is hot expansion of the occasion, the valve closed, the interval of a certain time, the hand wheel counterclockwise reverse a little to prevent the stem to death.
4 valve packing often encounter fault maintenance methods
        phenomenon
        Packing at the leak
        the reason
        Packing selection is not right, intolerant medium corrosion, intolerance of high pressure or vacuum valve, high temperature or low temperature use;
        Fill the installation of the wrong, there is a small generation on behalf of large, spiral coiled joints bad, tight under the loose and other defects;
        Packing over the use of the period, has been aging, loss of flexibility;
        Stem precision is not high, there are bending, corrosion, wear and other defects;
        The number of fillings is insufficient, the gland is not pressed;
        Glands, bolts, and other parts are damaged, so that the gland can not be pressed;
        Improper operation, excessive force;
        Gland skew, gland and stem between the gap is too small or too large, resulting in stem wear, packing damage.click this website
        Maintenance method
        The material and type of packing shall be selected according to working conditions;
        According to the relevant provisions of the correct installation of packing, packing should be placed by pressing, the joints should be 30 ℃ or 45 ℃;
        The use of the period is too long, aging, damage to the filler should be replaced;
        Stem bending, after wear should be straightening, repair, serious damage should be promptly replaced;
        Fill should be installed in accordance with the provisions of the number of laps, gland should be symmetrical even tight, pressure sets should be more than 5mm preload gap;
        Damaged glands, bolts and other parts should be repaired or replaced in time;
        Should comply with the operating procedures, in addition to the impact of hand wheel, the normal operation of uniform power;
        Should be evenly symmetrical tighten gland bolts, gland and stem gap is too small, should be appropriate to increase the gap, gland and stem clearance is too large, should be replaced.