With the development of society, the demand for valves is becoming more and more extensive, whether in construction, industries or people’s daily life, the applications of industrial valves can be seen everywhere. Among those industrial valves, globe valves and gate valves are two widely used types of valves.
Structural principle of globe valve
The globe valve is one of the most widely used industrial valves, and it is a favorite valve among the majority of customers. The globe valve won’t generate excessive friction pressure during the working process, can achieve reliable sealing performance. The globe valve has longer service life, and is easy and cheap to fabricate. Globe valve is usually used in low pressure pipeline systems, and also can be used for high pressure conditions.
The opening and closing part of the globe valve is a plug shaped disc, which moves along the center line of the valve body, the sealing surface of the disc and the valve seat can be closely overlapped by the pressure exerted by the valve stem. The flow direction of the globe valve is fixed, which means the mediums can only flow from one side to the other, so the globe valve should be installed according to the flow direction requirements.
Structural principle of gate valve:
The gate valve is an automatic sealing industrial valve. The traditional gate valve basically adopts the mandatory sealing structure. With the development of valve technology, the new designed gate valve can rely on the pressure generated by the flow of the medium to press the sealing surface to the valve seat to realize better sealing effect. Which is the so-called self-sealing of the gate valve.
The opening and closing part of the gate valve is the gate plate, which can only be fully opened or fully closed. The movement direction of the gate plate and the flow direction of the mediums are perpendicular to each other. The gate valve moves in a straight line with the valve stem. Usually, the lift rod has a trapezoidal thread, through the nut at the top of the valve and the guide groove above the valve body, the spiral motion is converted into a linear motion. Operation torque is converted to the operating thrust.
The difference between globe valve and gate valve:
1. globe valve and gate valve has some difference in sealing surface:
The sealing of the globe valve is mandatory, and it must rely on external pressure to achieve the sealing effect. When the globe valve is fully closed, the valve core will contact with the sealing surface, but because there is no much contact between that two parts and relative slippage is small, the wear on the sealing surface is not large, the wear of the sealing surface is mostly generated due to the high speed scouring of the medium and the damage of the impurities on the sealing surface itself. The gate valve is a self sealing valve, which rely on the fluid flow to generate pressure to press the sealing surface to the sealing surface of the valve seat to ensure that the sealing surface are tightly overlapped.
2. the globe valve and gate valve has different flow direction requirements;
The flow direction of the globe valve is from bottom to the top, while the flow direction of the gate valve has no requirements for the direction of inlet and outlet.
3. globe valve and gate valve has different resistance coefficients:
The resistance coefficient of an ordinary globe valve is about 3.5-4.5.
The resistance coefficient of an ordinary gate valve is about 0.08-0.12.
Compared with gate valves, globe valves are simpler and lighter, have stronger sealing performance and are easier to maintain; however, gate valves have short opening and closing stroke, fast opening and closing speed, and less resistance to fluids. These two types of valves are fully open and fully closed valves. They can not be used to adjust the fluid, but can only be used to cut off or connect the mediums, they are both widely used. They are used as a controlling device in pipelines with various mediums like air, water,steam, mud, oil, and some corrosive mediums.
for more information or prices about globe valves and gate valves, kindly contact us: