Check valve is a mechanical device that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, having two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. They are often part of common household items. Check valves work automatically and most are not controlled by any external control. Most of the valves do not have any valve handle or stem. The external shells of check valves are made of plastic or metal. The check valve is designed for operating in a specific cracking pressure.
Checkweighing Bench Scales are used for basic weighing, check weighing, and parts counting. These scales have higher capacities and extra standard features. The built-in memory can store high and low limits for up to ten samples, allowing the most commonly tested items to be checked even faster. To minimize overfill errors, a capacity tracker has been added to alert operators with audible and visual signals when the scale's capacity is being exceeded. The bi-directional interface allows data to be transmitted to printers or PC's. The final upgrades are added to the new CBK line include built-in time date/time for better tractability, and multi-language text output. The numeric keypad allows to enter numeric values for preset tare, check weigh limits and piece weights while the color-coded keys quickly identify the most commonly used functions. The scale's large backlit LCD display is easy to read even in poorly lit industrial locations. The internal rechargeable battery with low-battery indicator permits the CBK to be used where external power is not readily available. It has six models ranging from 8-lb/4000 g x 0.0002-lb/0.1 g to 100-lb/48000 g x 0.005 lb/2 g.