MT8 Pulseless Metering Pump
That is the best way to sum-up the MT8 metering pump manufactured by Wanner Engineering. Introduced in 2016, the MT8 has a triplex design pump head, which means it has three pump chambers with a common inlet and outlet manifold.
All positive displacement pumps have some form of pulsation and until now, most applications required pulsation dampeners to help optimize the dosage rate. The requirement for pulsation dampeners and the headaches associated with them disappear with the MT8 design due its high frequency pulse rate and patented hydraulic piston design. So, when we say “pulseless” we are referring to the observable flow and resulting performance appearing “pulseless”.
Mechanically actuated (solenoid or motor driven) and hydraulically
balanced diaphragm style metering pumps require a replenishment of hydraulic
actuation oil for proper functioning. The frequency and efficiency of
replenishment corresponds to the accuracy of the volume displaced. The
MT8’s patented replenishment system outperforms conventional vacuum and
mechanical actuated replenishment valves, optimizing accuracy.
The yellow area represents the accuracy requirements of ±1% per API 675 Metering Pump Standards and the blue area represents the ½±% range with the dots representing actual performance.
The yellow area represents the API 675 ±3% requirement with the dots
representing the actual performance. Speed and Flow Rate Relationship
Speed and Flow Rate Relationship
Returning to ±3% of the set point after changing RPM
The yellow area represents the API 675 standard and the dots represent the flow rate after decreases and increases to pump shaft speed.
The Wanner Engineering MT8 sealless metering pump design has no leakage paths between the process fluid and mechanical portions of the pump, providing several advantages to its users, but namely reliability.
Piston style metering pumps have a plunger, which comes in direct contact with the pumped fluid and thus requires packing to create a seal between the hydraulic and process fluid sides of the pump. The plunger constantly slides through the packing, wearing it down, eventually providing a leakage path for contamination of the pumped fluid as well as fugitive emissions through the hydraulic end of the pump. Adjusting and replacing gland packing – along with that potential leakage path, is eliminated with the MT8 design.
Plunger designs use packing and have two other weaknesses that the sealless MT8 does not:
- Particulate within the fluid can accelerate wear of the plunger and that area of interface is an area where particulate can remain lodged.
- The interface between the plunger and packing is dependent upon the fluid being pumped for cooling and lubrication, thus if the pump operates dry due to a system upset such as an empty feed tank, the resulting friction will significantly accelerate wear of the packing.
The MT8 can operate dry indefinitely and there are no leakage paths for particulate to accumulate.
Unlike mechanically actuated diaphragm designs (either solenoid or motor driven), the MT8 can operate with a restricted or blocked suction line because its design limits the position of the diaphragm, preventing it from moving too far forwards or backwards.
Check valve materials:
Pump head materials:
Problem Solving Pump
The sealless design of the MT8 combined with its extreme accuracy has
solved difficult metering pump applications involving sheer-sensitive fluids
with suspended particles. Whether due to crystallization or improper
mixing, if the particles are ≤ 200 microns in size it will not affect pump
Examples of such applications include:
The flow rate of a metering pump is controlled by adjusting the stroke length, stroke speed or a combination thereof. Mechanical adjustment of the stroke length, whether via amplitude modulation or lost motion, increases the complexity of the pump design.
MT8 catalog pages and IOM
We can provide the complete pump/motor/VFD/PLC assembly, however we'll require additional information from you to properly size and select the motor and optional controllers. The best thing to do is to view our brochure and then use our email inquiry form to provide us with the design criteria.