Pumps are often touted for their high-capacity flow rates, and this is important in many applications such as bulk transfer, gland seal flushing and saltwater disposal. For metering applications where precision and accuracy take precedence, just the opposite—low flow rates—are often required. Since it is metering, a pump should also meet the American Petroleum Institute (API) 675 standards for steady-state accuracy (plus or minus 1 percent), linearity (plus or minus 3 percent) and repeatability (plus or minus 3 percent). Less common in the chemical metering world is the electric operated double diaphragm (EODD) pump. A relatively new technology, EODD pumps are establishing themselves as an alternative to peristaltic pumps in metering applications. When used with the proper electronic controls, the cycle rate on an EODD pump is monitored to ensure flow matches the required metered rate.
An alternative for metering in chemical applications.
Graco Inc.
09/19/2018
Image 1. An EODD pump in an installation (Images courtesy of Graco Inc.)
Image 2. The initial investment on an EODD pump is typically less than other industrial pumps.
This, along with the relative ease with which a diaphragm pump can be repaired as well as the minimal cost of service parts make diaphragm pumps a wise choice financially. Market research also shows maintenance personnel would prefer to service a diaphragm pump due to the nature of the repair process.
As an added advantage, the initial investment on an EODD pump is typically less than other industrial pumps.