The ANSI design was created in an effort to make replacement pumps easily accessible. All ANSI pumps are manufactured to be dimensionally interchangeable and have a back pull-out design. This allows facilities and plants the opportunity to source pumps from multiple manufacturers without changing their pipe schematic and design. The MXQ G-Line Series is 100% interchangeable with the Goulds 3196 and the MXQ D-Line Series is 100% interchangeable with the Durco Mark III.
ANSI pumps have been in process for nearly 6 decades and continue to be one of the most popular pump products in the market.
MXQ G-Line Series pumps are supplied with open impellers which set against the casing. This design allows for the pumping of stringy solids to a certain extent. These impellers generally create higher head, and efficiency is maintained by a large setting area along the lead edge of the impellers. Hydraulic balance is done by back pump-out vanes that eject solids and pressure from the seal area and balance the hydraulic thrust operating against the front and back of the impeller; thus, lowering thrust bearing temperatures and loads. The seal chambers are available in standard cylindrical bore, taper bore with anti-rotation lugs, and big bore, tapered with the lugs. Impeller adjustment is by jack-bolts and lock nuts. 4 power frames are available for maximized performance.
MXQ D-Line Series pumps are supplied with reverse-vane impellers that have balance holes and set the clearances off of the rear cover or seal plate. Since the impeller setting does not involve casing clearance, it can be set on the bench. Furthermore, since the two surfaces are flat and not curved, they can be verified with feeler gauges. The impeller adjustment automatically re-establishes the hydraulic balance and seal chamber pressure as well. The advantage over the open impeller is that an adjustment forward to the casing, opens the clearance on the back pump-out vanes and allows seal pressure and thrust to climb; meaning hotter seal faces and bearings. The impeller adjustment is accomplished by a threaded bearing carrier that utilizes a micrometer on the carrier itself to adjust the clearance. By drawing the impeller back to touch-off and then rotating ¼ turn, the impeller is moved forward about 0.020” and then the locking bolts set the measurement. 3 power frames are all that is needed for the complete line. Group II bearings and shafts generally exceed ANSI requirements for power and torque, while G-Series requires both MTX and LTX to handle the same services. The same seal chambers are available in both designs.