PUMP SPECIFICATION-DME
To define the metering pump to use, please add these
sections to the basic dosing and/or metering pump specifications
- Dosing
pumps shall be motor driven with positive movement during both suction and
discharge strokes. Neither Solenoid driven type pumps nor motor driven
pumps that use a spring to complete the pumping cycle is acceptable.
- The
pump’s stroke length will always be 100%. No adjustment to the stroke
length, to regulate flow ,or for other reasons,
is acceptable.
- A
digital keypad will be used to set the required flow rate.
- The
pump shall maintain a repeatable accuracy throughout a full range of the
pump’s performance capability. A true 1000:1 turndown ratio shall be
maintained (i.e. a pump rated at 2 gph shall be equally accurate at .002
gph as at 2gph).
- Accuracy
shall be repeatable when the flow rate is changed. If the flow is changed, and then reset
to the original flow,
the original flow shall be achieved without recalibration.
- The
pump shall be driven by a stepper type electric motor.
- The
pump enclosure shall be rated to IP65 standards.
- The
pump shall be listed by UL as a chemical process pump (category RBOG).
- The
pump shall include an electronic lock to prevent tampering.
- The
pump shall include manual, analog and pulse control settings. If the
analog mode (4-20 mA) is used, the pump shall have onboard ability to
extend or invert the input signal (20-4mA, 0-20 mA or 20-0 mA).
- In the
analog mode, the Maximum Capacity of the pump shall be capable of being
lowered to more fully
employ the range of the 4-20mA signal.
- The
pump shall have the capability to lengthen the suction stroke
characteristic to accommodate either viscose or ebullient types of fluids
- The
pump shall display the actual flow in US
standard (GPH) or Metric standard (l/hr or ml.). Changing from one unit of
measure to the other shall be an easily accomplished, field settable,
function.
- The
pump shall include a 100% button to aid in priming. When priming is
complete, the pump will automatically revert to preset conditions.
- Pump
check valves shall be of a cartridge design for ease of maintenance. The
discharge and, at least, one of the suction valves shall be
interchangeable. Direction of flow shall be clearly marked on each check
valve to insure correct installation.
- When
either the Polypropylene or PVDF pump is used, the tubing type end
connections shall be designed to seal to the maximum pressure rating of
the pump. Stainless steel wetted
pumps, only, shall use NPT connections
- The
pump shall be a Grundfos model DME, Digital Dosing™ pump.