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Globe valve

if change of direction is there valves are called angle valves, valve seats and lids are generally stelitted. It doesn’t give full bore and change of direction is also there so there is a drop in pressure. Sdnr type valves are used in bilge systems. This is to prevent back flow, so when testing for leak checks in bilge system remove valve lid and perform.                                                                                                                   
Globe valve overhaul:
  •  Clean, buff, and polish all the parts.
  •  Check all the threaded parts for damage and if there is any damage on the thread then the threads must be dressed by a needle file.
  • Check the stem for straightness. The simplest method of checking is by rolling on a flat surface, but the correct method is to put it on a lathe and center it. Thereafter with the help of a dial gauge put on a magnetic stand at a suitable point, check the distortion.
  •  Check the stem for scratches, as these can damage the gland packing. Any scratches must be removed with an emery paper or oil stone.
  • The valve and the valve seat must be inspected and if found to be in fairly good condition, they must be ground together by using a guide for centering and a suitable grade lapping paste. A 1200 grit lapping paste would be suitable in most conditions.
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