Brass Check Valve
Though not necessarily as strong as other metals such as steel, brass is easily alloyed to include additional materials such as titanium and antimony to increase strength as well as corrosion resistance. This is essential to
check valve function as the material construction must be compatible with the process stream composition, which may be basic, acidic, corrosive, abrasive or even hazardous. More mundane materials such as water and syrup may be forced through these
non return valves as well. Finishing options such as hardening, cold working, nickel plating and lacquering also increase the usability of brass valves, which are now found in a number of industrial, commercial and even domestic plumbing applications where gases and fluids must maintain unidirectional and forward flow. Water and sewage treatment, agricultural, medical, chemical processing, food processing and petrochemical facilities are just a few that utilize brass check valves to prevent backflow that could otherwise cause serious damage to equipment and materials.
As brass refers to the material construct rather than a specific check valve, it can be incorporated into virtually every type of valve, including
ball check valves,
wafer check valves,
lift check valves and
swing check valves. Although the designs may vary considerably, the basic function of all brass check valves is fairly similar. The valve body, a cylindrical or spherical element, is installed in the pipeline. In the middle of this apparatus is what is known as the seat, a cross-sectional element that extends from the inner walls of the pipeline and has a central gap. An oversized stopper or plug rests in this seat, which sometimes incorporates an elastomeric seal for added protection against leaks. When fluid or gas flows in a forward direction and at a high enough pressure, the stopper is pushed away from the seat and the gap is opened to allow the stream through. As pressure drops, gravity or a spring mechanism push the stopper back into place, creating a tight seal that prevents backwash. Because check valve operation is entirely reliant on the pressure flows of a given process stream, no external activation or actuation mechanism is required. The valves are therefore easily installed into pre-existing pipelines, which also helps to determine the necessary valve size as it must correspond to the diameter of the pipe. Additional considerations include minimum and maximum pressure ratings, media temperature and the valve flow coefficient.
