A Better Solution for your Horizontal Progressing Cavity Pump Applications2021 November 15
Horizontal (surface) progressing cavity pumps (PCP) or PC pumps have been around for quite a while. The operation of a PC pumprelies on a rotor that orbits (turns eccentrically) inside a stator, like a grain auger. The motion creates cavities that push the fluid along.
XFER multiphase pumps, in contrast, feature a straightforward bidirectional piston inside a barrel, with each back-and-forth stroke producing a suction stroke and a discharge stroke. As the unit cycles in one direction, a discharge check valve opens on one end and a suction check valve opens on the other end, so that one side of the piston is compressing and the other is in suction. At the end of the stroke, the piston reverses direction, an opposite set of suction and discharge check valves opens and produces an opposite direction suction and compression stoke.
Issues with PC Pumps
While a PC pump’s operating concept is fairly simple, the design suffers from three main issues that the XFER multiphase pump is better able to manage:
In the case of a PC pump, its design is inherently susceptible to wear between the spinning rotor and the elastomeric (plastic) stator.
XFER Abrasion Solution
With an XFER, there is only reciprocating motion and with a NiCarb (industrial diamond) coating on the inside of the barrel, along with specialized seals that sweep abrasive materials away, wear is dramatically reduced.
PC pump materials are especially affected by temperature, causing stator elastomers to swell and as temperature drops, elastomers shrink. This changes the compressive fit between the rotor and stator.
XFER Temperature Solution
Temperature has virtually no effect on an XFER. Since it is made of all metal components, expansion and contraction rates are consistent among the components. In addition, the XFER’s smart software prevents the unit from ever overheating by slowing the unit down if necessary, until normal conditions return.
Even at reduced speeds, PC pumps may not develop 100 per cent volumetric efficiency and this must be accounted for in the selection process, meaning the units don’t adapt well to changing conditions.
XFER Viscosity Solution
An XFER can pump a very wide variety of materials and viscosities. The XFER’s smart software allows the unit to respond to conditions to maintain efficient production. Simply set the parameters needed and the unit will automatically adjust to meet them.
Damage to Progressive Cavity Pumps
PC pumps are relatively complicated and consist of a lot of parts that can wear and fail:
PC pump stator wear, fatigue, delamination, high torque damage:
The XFER has a simple mechanical design with few parts that can wear. In addition, components in contact with corrosive production fluids are made of materials with extreme corrosion resistance, such as N50 and NiCarb barrel coatings, giving XFERs extreme resistance to attack from very corrosive fluids, including salts, H2S etc.
In summary, the benefits of choosing an IJACK XFER multiphase pump over PC pumps:
- No cavitation issues
- No rotor wear
- No issues with temperature affecting the stator-rotor clearances
- No chemical attacks on the rotor causing pitting, or attacking base metal under the chrome plating
- No chemical attacks degenerating the inner surface of the stator or causing it to swell or shrink
- No running dry, damaging the inner surface of the stator or galling on the rotor from becoming soft and tacky from heat
- No elastomeric stators coming loose from the housing at higher discharge pressures
- No fatigue causing stator material to vulcanize and have chunks break loose
- No rotating shafts to shear
- No rotating gears to wear
- No gear boxes to wear, and reduce efficiency
Contact IJACK for more information.