- O-type ball valve structure and characteristics
O-type ball valve's sphere is a whole ball, and the flow outlet is round, so it is called O-type ball valve. Most of the ball valves we use are O-type ball valves. Its flow resistance is small, the switching process only needs the spool to rotate 90 degrees, so the switching speed is fast, equipped with AT cylinders can be used as a quick cut-off valve. Its inlet and outlet have two seat seals, reliable sealing. It can be used for gas, steam, liquid and medium containing a small amount of suspended particles. Design standard reference GB/T12237-2021 "steel ball valves for petroleum, petrochemical and related industries".
O-type ball valve with floating or fixed design, the relative movement parts are used in the friction coefficient is very small self-lubricating materials, so the operating torque is small, in addition to the sealing grease long-term sealing, so that the operation is more flexible.
(1) O-type ball valve fluid resistance is small. Ball valves generally have through, reduced two structures, regardless of which structure, the ball valve flow resistance coefficient is relatively small. Conventional ball valves are straight-through, also known as full-flow type ball valves, the channel diameter is equal to the inner diameter of the pipe, the resistance loss is only the friction resistance of the same length of pipe.
(2) O-type ball valve switch quickly and easily. The ball valve only needs to turn 90 degrees to complete the full open or full closed, so it can quickly achieve open and close.
(3) O-type ball valve sealing performance is good. The vast majority of ball valve seats are made of polytetrafluoroethylene (PTFE) and other elastic materials, usually called soft seal ball valve, soft seal ball valve has good sealing performance.
(4) O-type ball valve long life. As PTFE has good self-lubrication, and the friction coefficient of the ball body is small, thus greatly improving the service life of the ball valve.
(5) O-type ball valve is highly reliable. O-type ball valve is fully open, both sides of the smooth for the non-obstructive valve, the formation of a straight pipe channel, two-way sealing, with "self-cleaning" performance of the best features, suitable for the two cut-off occasions, especially unclean, containing fibrous media. Ball core in the process of opening and closing the valve is always friction with the valve, at the same time, the seal between the valve core and the valve seat is through the seat pressure to the ball core of the pre-tightening sealing force to achieve, but due to the soft sealing seat of its excellent mechanical and physical properties, making its sealing is particularly good.
- V-ball valve structure and characteristics
V-ball valve is a kind of high-efficiency valve, its design is unique, with a hemispherical body spool side of the opening V-shaped port. Large flow capacity, adjustable range, shear force, can close tightly and other characteristics, especially for fluid substances with fibrous conditions. In general, V-shaped ball valve is a single seal ball valve. It is not suitable for bi-directional use. By adjusting the spool opening, you can effectively change the cross-sectional area of the media flow, to achieve precise flow control, but also can be used for switching control, to achieve the opening or closing of the pipeline. The valve has a self-cleaning effect, can be achieved in a small opening range of small flow adjustment, adjustable ratio. It is suitable for media containing fibre, fine particles and slurry.The code of V-type ball valve is VQ, and the design reference standard JB/T 13517-2018 "V-type ball valve". With a high degree of reliability and stability, it is an indispensable and important component in the field of fluid control.
During the rotation of the ball, the V-shaped cutter of the ball is cut with the valve seat, thus cutting off the fibres and solids in the fluid, while general ball valves do not have this function, so it is easy to lead to the fibre impurities stuck when closing, which brings great inconvenience to the repair and maintenance. The V-ball valve spool will not be stuck by the fibre. In addition, due to the use of flange connection form, and thus its easy disassembly, without special tools, maintenance is also simple and easy. When the valve is closed, the V-notch and the seat of the valve to produce a deed-shaped scissor effect, and both self-cleaning function and can prevent the ball core jammed, the valve body, the valve cover and the valve seat were used in the metal point-to-point structure, in addition to the use of a smaller friction coefficient of the valve stem spring, so the operating torque is small, very stable.
V-ball valve is a right-angle rotary structure, can achieve the role of flow regulation, can be based on the V angle of the V-ball body, to achieve different degrees of proportionality, V-ball valves are generally used in conjunction with the valve actuator and positioner to achieve proportionality, V-type spool is most suitable for a variety of regulating occasions, with a large coefficient of flow rating, adjustable ratio, sealing effect, zero-sensitive regulating performance, small size, can be vertically and horizontally mounted. Suitable for controlling gas, steam, liquid and other media. v-ball valve is a right-angle type rotary structure, composed of v-body, pneumatic actuator, positioner and other accessories; there is an approximate equal hundred ratio of the intrinsic flow characteristics; the use of double-bearing structure, start-up torque is small, with excellent sensitivity and sensing speed, superb shear capacity.
- The difference between the two
(1) different spool structure, O-type ball valve flow path for a complete circle, with double seat seal, V-type ball valve is 1/4 half ball spool, one side of the V-shaped port, with a single seat seal. There is also a global spool, one end of the open V-shaped flow channel port, single seat seal or double seat seal form.
(2) suitable for different media, O-type ball valves are used for clean media, or a small amount of suspended particles in the media, PTFE PTFE seat seal, can achieve zero leakage. But in the medium contains more impurities, or granular media, easy to occur in the cavity blockage, resulting in the ball valve hold dead, switching failure. v-type ball valves are mostly metal hard seal, used for fibre-containing, fine particles, slurry media. Because the V-shaped port and seat can cut fibre media, so widely used in the paper industry. Due to the use of part of the spherical spool, and is a single seat seal, effectively preventing the medium from blocking the valve.
(3) process control requirements are different. o-type ball valves are mainly used for switching control, regulating performance is not good. Fitted with AT pneumatic piston actuator, can achieve rapid cut-off. v-ball valve with V-shaped port, adjustable, adjustable ratio is large, up to 100:1 or higher. Equipped with pneumatic and electric actuators, mainly used for regulating control, can also be used for switching control.
(4) different flow characteristics, O-type ball valve flow characteristics are fast-opening, suitable for switching control, V-type ball valve flow characteristics are approximate equal percentage, suitable for regulating control.
(5) different size of the flow path, O-type ball valve flow path size generally have two kinds of full diameter and reduced diameter, V-type ball valve flow path according to the process and design requirements of different sizes, generally are reduced diameter. Different ball core can be replaced to meet different flow requirements.