Stainless steel globe valve "low into high" and "high into low out" "high" and "low" refers to the cut-off valve structure shape, down along the stem and the valve stem downward convex portion is " Low "and the channel next to the valve chamber is slightly above (relative to" low "). The stainless steel globe valve is normally low and high, depending on the structure of the shut-off valve chamber. Refers to the fluid into the valve, the valve cavity, the flow from low to upward, and then out of the valve body. Valve flap at the top of the valve chamber. Media from the bottom of the valve into the disadvantage is that the valve drive torque is larger, about 1.05 to 1.08 times higher than the above, the stem by the axial force, easy to bend the stem.For this reason, the media from the bottom into the way, generally only applies to small-diameter stop valve (DN50 below), DN200 above the globe valve Selection of media into the way from the top.Electric stop valve is generally used from the media into the top of the way.Medium from the top into the shortcomings of the way just below and into the opposite way.General design requirements, DN≤200mm PN≤4.0MPa of the globe valve, Use low-level When the DN> 200mm or more, the choice of high into and low out. Cut-off valve flap for the double-valve flap structure. Because when the diameter is greater than 200mm, due to larger flow, the pressure per unit area is large, Need a lot of the opposite force to ensure that the seal.This must stem increased, and must use the impact handwheel or the use of large torque worm gear. Increased the valve size and product cost, and the effect is not good. Out helps to seal (after the closure of the media since the pressure to strengthen the sealing effect), but when open due to overcome the media pressure, more difficult. "Is conducive to sealing, medium pressure valve seal more closely, stem pressure conditions improve. In short, the valve marked on the flow direction, according to the flow can be installed.