Installation direction of the Y-type stop valve?

The actuator of the Y-type stop valve should be on the low-pressure side.

According to the design, I think the terms \"pressure bearing\" and \"end pressure-bearing end\" are not accurate; moreover, it is mainly done to facilitate the operation of the valve and extend its service life

What I know is about issues related to pressure resistance, such as the thickness of the valve stem. Regarding the theory of globe valves, those with a diameter of DN150 or less have flow from low to high, while those with a diameter greater than DN200 have flow from high to low. But this is certainly not absolute.

The stop valve must be installed in accordance with the flow direction indicated on the valve body. When installing a stop valve, it can be connected to the valve core in two ways: with the medium entering from below and exiting from above, or with the medium entering from above and exiting from below. The advantage of allowing the medium to enter from below the valve core is that the packing is not under pressure when the valve is closed, which extends its service life; moreover, it is possible to replace the packing even when there is pressure in the pipeline ahead of the valve. The disadvantage of the medium entering from below the valve core is that the driving torque required to operate the valve is higher, at about 1.05 to 1.08 times that of when the medium enters from above; moreover, the axial force on the valve stem is large, causing the stem to bend easily. For this reason, the method of feeding the medium from below is generally only suitable for small-diameter globe valves (DN50 and below). For globe valves larger than DN200, the medium flow direction is from high to low. It is used when high sealing performance of the valve is required; the thrust of the medium enables the valve disc to make closer contact with the valve seat, thereby enhancing the sealing effect. Electric globe valves generally use a flow pattern in which the medium enters from the top and exits from the bottom.

Yes, there are. If the Y-shape stop valve is installed for maintenance purposes (usually in an open position), its self-sealing function should be utilized to enhance sealing performance. The pressure condition of the valve core when it is closed facilitates a self-sealing arrangement; therefore, it should be installed in a forward and reverse configuration (that is, for normal flow direction, the upstream valve has high inlet and low outlet, while the downstream valve has low inlet and high outlet).