Cast Iron globe valve is a forced-sealing valve, so when the valve is closed, pressure must be applied to the disc to force the sealing surface to not leak. When the medium enters the valve from below the disc, the resistance that the operating force needs to overcome is the friction force of the valve stem and packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so Cast Iron The diameter of the valve stem of the globe valve should be large, otherwise the valve stem will bend up failure.
2. Parameters of Cast Iron Globe Valve
Type of Valve
Cast Iron globe valve
Design Temperature Range
Manual drive, Pneumatic, Hydraulic or electric Actuator
Water, oil, gas, and various corrosion medium
Body Cover Disc
Forged steel, Cast steel
Forged steel, Cast steel
Flexible Graphite, Enhanced Flexible Graphite, PTEE
Enhanced Flexiblo graphite, stainlness steel, PTFE
13Cr, STL, PTFE, Nylon, With Body material
3. Advantages of Cast Iron globe valve
1) The structure of the Cast Iron globe valve is simpler than that of the gate valve, and it is more convenient to manufacture and maintain.
2) The sealing surface of Cast Iron globe valve is not easy to wear and scratch, and the sealing performance is good. There is no relative sliding between the valve disc and the sealing surface of the valve body when opening and closing, so neither abrasion nor abrasion is serious. The sealing performance is good and the service life is long. .
3) When the Cast Iron globe valve is opened and closed, the disc stroke is small, so the height of the shut-off valve is smaller than that of the gate valve, but the structure length is longer than that of the gate valve.
4) Cast Iron globe valve has a large opening and closing moment, which is laborious and takes a long time.
5) The medium channel in the Cast Iron globe valve is tortuous, the fluid resistance is large, and the power consumption is large.
6) When the nominal pressure of the medium flow direction of the Cast Iron globe valve PN≤16MPa, the downstream flow is generally adopted, and the medium flows upward from the bottom of the valve flap; when the nominal pressure PN≥20MPa, the reverse flow is generally adopted, and the medium flows downward from the top of the valve flap. In order to increase the seal performance. When in use, the shut-off valve medium can only flow in one direction and cannot change the direction of flow.
7) The valve flap is often eroded when the Cast Iron globe valve is fully opened.