Y Type Bellows Cast Steel Globe Valve
Basic Info
Model No.: YB75
Product Description
Y Type Bellows Cast Steel Globe Valve
DC bellows shut-off valve (also known as Y-valve)
The structure of the DC bellows Globe Valve. The fluid flow path of the DC valve is much slower than that of the straight-through DC bellows shut-off valve. The fluid resistance is small, but the valve stroke is large, and the manufacturing, installation and maintenance are complicated, and it is only used in places where the fluid resistance is strictly required. Ammonia valve,Chlorine valve, Bellows Globe Valve, Ball Valve, Check Valve
3) The structure of the angle stop valve, the valve body is mostly forged, its structure is simple, the mechanical properties are good, suitable for high pressure, small diameter stop valve.
4) The stem of the DC bellows stop valve is generally rotated and lifted. When the handwheel is rotated clockwise, the stem is closed and the valve is closed. Turn the handwheel counterclockwise, the valve stem up and open the valve. The valve stem thread of the DC bellows stop valve has two kinds of upper thread structure and lower thread structure.
The running thread of the upper threaded stem is outside the valve stem and outside the valve body packing box. The thread is not in contact with the medium, is not corroded by the medium, is easy to lubricate, the valve stem is stable and not easy to bend, and the valve disc and the valve seat are aligned. Good, good for sealing. The upper threaded stem is suitable for DC bellows globe valves with large diameter, high temperature, high pressure or corrosive media.
The running thread of the lower threaded stem is at the lower part of the stem and in the stem cavity. When the lower threaded stem is in operation, the thread can be in contact with the medium, which is susceptible to corrosion by the medium, and has a large viscosity and a medium with suspended solids, which is easy to condense the liquid and can cause the thread to jam. The advantage of the lower threaded stem is that the stem length is shorter and the length of the valve body can be reduced. The lower threaded stem is typically used for small diameter, low temperature and non-corrosive, clean media DC bellows shut-off valves.
5) Sealing ring of DC bellows stop valve The disc valve disc and the sealing ring on the valve seat are the key components of the channel seal of the DC bellows stop valve. Its common structure and fixing method.
Figure 4.9(a) is a sealing structure for a low-pressure small-diameter DC bellows globe valve. The valve disc seal is made of soft material such as rubber or plastic. The soft Seal Ring is fixed to the metal valve by screws. On the flap. The seal on the seat is made of copper alloy. It is also possible to machine the sealing surface directly on the valve seat.
Figure 4.9(b) shows the sealing structure for a medium-pressure small-diameter DC-type bellows shut-off valve. The sealing surface is directly machined on the valve flap. The seat sealing surface is a ring seat made of chrome stainless steel, and the ring seat is screwed to the valve body.
Figure 4.9(c) is the sealing structure for the low-pressure DC bellows globe valve. The oblique valve and dovetail groove are respectively machined on the Cast Iron Valve body and the valve disc, and the copper alloy sealing ring is pressed into the groove respectively. , fixed by plastic deformation.
Figure 4.9(d) is the sealing structure for the small-diameter DC bellows stop valve. The sealing surface is directly machined on the valve disc, and the sealing ring made of copper alloy or stainless steel is pressed into the dovetail groove of the valve seat. .
6) Balanced DC type bellows stop valve has a valve flap structure, and the fluid flow direction is opposite to that of a normal DC type bellows stop valve. The balance type DC bellows stop valve has a small hole passage connecting the upper part and the lower part. When opening and closing the valve, the valve stem first opens the small hole passage to balance the pressure of the upper part and the lower part of the valve flap, and relieve the valve flap The total pressure when the surface is stressed also greatly reduces the driving torque when opening and closing the valve, and overcomes the defects that the single-sided pressure of the high-pressure, large-diameter DC-type bellows stop valve valve is too large, the sealing surface is vulnerable and the operation is difficult. However, due to the complicated structure of the balanced valve disc, it is generally only used for DC-type bellows stop valves with high pressure and large diameter.
7) Bellows DC bellows globe valve bellows DC bellows globe valve is a DC bellows globe valve with double seal on the valve stem. In addition to the packing seal of the general valve, there is also a stainless steel bellows. Seals. Since the bellows has elasticity, when the valve flap is lowered, the bellows is elongated and compressed when rising, so that the bellows seal can prevent fluid leakage. If the bellows is damaged, it can be detected from the leak detector. At this time, the filler is used for the second seal, and the work can be continued and standby maintenance. The valve can be used in both vacuum systems and medium and low pressure pipelines with high sealing and cleanliness requirements. It is also suitable for opening and closing devices in toxic, flammable, explosive, and radioactive fluid pipelines.
Product Categories : Globe Valve > Straight Globe Valve