Metering equipment includes any number of devices used in the metered pumping of precisely measured fluids from an area of high pressure to an area of low pressure. The pump itself is the primary component in metering systems. Used to cyclically introduce a consistent amount of fluid into a continuous-flow stream, metering ensures the homogeneity of a final product or process stream.
Related Categories
While manual models of metering equipment are widely available, automated pumps are valued for uninterrupted operational capacities as well as computer accuracy. Computers or microprocessors are essential to automated metering as they monitor fluid dosing and pump efficiency. Metering pumps, both automated and manual are implemented in the daily operations of a broad array of industries including chemical, pharmaceutical, food and beverage processing, water treatment, medical, commercial vending, irrigation, petroleum, milling, sewage, plastic fabrication, metalworking and laboratory. In order to accommodate these varied needs, large and small metering pumps are available in a number of configurations and can be used in applications requiring extreme precision and reliability, such as artificial heart pumps, as well as more industrious uses, like crude oil production. Variable displacement constant speed and fixed displacement variable speed models allow manufacturers to adjust flow rates as needed by changing either the stroke length or the cycle frequency of metering equipment. Fluid transfer engineers and pump manufacturers can provide helpful insight into the capabilities of a fluid transfer or dispensing equipment.
Metering equipment is available in a wide range of configurations. Aside from the actuating device, however, most are similar in design and function, with the exception of peristaltic pumps. Each metering pump has a pump head, or cylindrical cavity which houses the fluids just before they are displaced or expelled. An inlet check valve and tubes or hoses connect the head and the fluid reservoir or source from which the fluid is extracted. An outlet connection is also available with a check valve to ensure liquid may be pumped into the processes stream but not return to the head. The mechanism used to enact pumping is also found in the main chamber. When this device is withdrawn it increases the volume of the cylinder creating a vacuum which draws fluid in. When it is extended back towards the base, volume is decreased and pressure forces the fluid out through the exhaust valve. Several different actuating mechanisms are used to achieve this. Diaphragm metering pumps engage the liquid with a vibrating membrane. Piston metering pumps are also popular and use a cylindrical plunger to alter chamber volume and pressure. Bellows pumps, which employ an expandable pleated body to compress and decompress fluids, may also utilize a piston to engage the bellows. Materials used to construct metering equipment range even more than the devices themselves. Aluminum, stainless steel, cast iron, brass and bronze are commonly used as are elastomers, rubber, plastics and even ceramic. Additional considerations for metering equipment include maximum flow, maximum pressure discharge, inlet size, exhaust size, media, operating temperature and power source.
