Handle butterfly valves and worm gear butterfly valves are collectively referred to as manual butterfly valves. According to the connection form, there are multiple connection forms such as wafer, flange, clamp, and welding; according to the sealing form, it can be divided into soft seal and hard seal. The advantages and disadvantages of handle butterfly valves and worm gear butterfly valves, let's talk about them in detail below.
The handle butterfly valve is simple in structure, light in weight, easy to install, disassemble, and maintain. However, due to its own limitations, the handle butterfly valve can only be used on small-diameter pipes. Usually, we stipulate that the handle can be operated on pipelines with a diameter less than DN200MM. If it exceeds this caliber range, the torque increases, and the handle opening and closing will become more and more difficult.
In addition, handle butterfly valves are generally soft-sealed. The advantage of this type of valve is that it has high sealing performance, can achieve zero leakage, and has good sealing performance. Handle butterfly valves are not suitable for hard seals. Hard seal butterfly valves are generally used on high temperature and high pressure pipelines. It is difficult to open the valve with the handle.
As mentioned above, the worm gear butterfly valve overlaps with the handle butterfly valve in use, that is, the worm gear drive can also be used on the butterfly valve with a diameter of less than 200mm, but the cost will be slightly higher compared with the handle operation.
Compared with the handle butterfly valve, the advantages of the worm gear butterfly valve are also obvious. First of all, the worm gear butterfly valve can be used on large-diameter valves, as small as 50 calibers and up to 1 meter or more in diameter, worm gear butterfly valves can be used. In addition, in the absence of special requirements, the drive mode of the hard seal butterfly valve is usually driven by a worm gear.
Which is more expensive, handle butterfly valve or worm gear butterfly valve?
Worm gear butterfly valves can be made with larger diameters, so worm gear butterfly valves are more expensive than handle butterfly valves. In addition, even under the same caliber, material, and specifications, the manufacturing cost of the worm gear butterfly valve is higher than that of the handle butterfly valve, and the price will be more expensive than that of the handle butterfly valve.