The trunnion valve is an old style of quarter turn valve that uses an open, perforated, fixed and stationary ball on which a fluid flows. The mechanical support of the ball allows it to absorb the momentum in the fluid line pressure, thus preventing excess friction between the stationary ball and seats. The trunnion valve has a number of advantages over the older form of valve.
Firstly, as the force on the lever moves back and forth, the valve’s mechanical force is reduced allowing greater flow rate. Secondly, the mechanism allows for greater resistance as the lever moves back and forth. Thirdly, the mechanism reduces or eliminates the need for lubrication and wear and tear.
Trunnion ball valves are often used for controlling flow in an industrial production process such as in the manufacturing of fluid lines or hydraulic systems. The mechanism is often used to regulate the flow in a continuous pressure system, to reduce air pressures and to control the level of hydraulic flow into the hydraulic pump. A typical system includes a housing that contains a trunnion plate, a cover plate and a ball, a fluid reservoir and a pressure switch.
Trunnion ball valves are available with either a straight line valve or a curved line valve. In most applications, the curved valve allows more precise control of pressure and the flow of fluid.
Trunnion balls are typically made out of polypropylene. It is important to make sure that the valves used for a particular application are the correct type of valve for that specific application to prevent the risk of excessive wear and tear on the valve.
Trunnion valves can also be fitted directly into a fitting box and are designed to fit into many different kinds of fitting boxes, including some internal and external fitting boxes. They can also be fitted in conjunction with other valves for example with a standard water control valve. Alternatively, a single trunnion valve can be incorporated into a hose and pipe joint a water control valve.
If you choose a trunnion ball valve, it is also important to ensure that the ball does not stick to the trunnion valve. Once the ball is fitted in the trunnion valve, there is little room for movement. As the ball is not moving, it also makes it much harder for the flow to flow in the appropriate direction.
When choosing trunnion ball valves, it is also important to consider the type of lubricant that is provided with the valve, particularly for the purpose of sealing. If the lubricant is too weak, the ball could easily break when the valve is closed.