• 8305 McIntyre Road, Edmonton, Alberta, Canada T6E 5J7

PL 5 Coupling

Plainsman PL5 Centralizing Couplings

Plainsman PL5 Centralizing Couplings are a spin-through, non-rotating style of sucker rod and drive rod centralizers designed specifically for reducing operating costs of progressing cavity pump applications.

The PL5 protects the well from accelerated road and tubing wear to reduce work over frequency, lifting lifecycle, and maintenance costs.

They are placed along the rod string at locations known or predicted areas of tubing wear. If running a Plainsman shear coupling (aka shear tool), it is recommended to run a PL5 centralizer both above and below the shear coupling to reduce the fatigue on the shear coupling.

They are field replaceable and available for 5/8″ to 1-1/8″ rod to fit in 2-3/8″ to 4-1/2″ tubing. The rotor is available in standard or high-performance materials good to 218°C.

At Plainsman, we manufacture and distribute products for oilfield production, pipeline maintenance, construction and gas, and water distribution. We have an in-house engineering department and a full-service manufacturing facility that enables us to respond efficiently to both our customer and industry needs.


Learn More about the PL5 Coupling

Feature of PL 5 Coupling

The PL5 Centralizing Coupling has many features that help reduce operating costs of progressing cavity pumped wells.

The centralizing couplings typically consist of a sacrificial rotor mounted on a mandrel between two shoulders. It is this sacrificial rotor that prevents tubing wear.

The mandrel will wear through the rotor before wearing through the tubing wall.

Features of the PL5 coupling include:

  • Reduces tubing wear in deviated and progressing cavity pumped wells
  • Available with abrasion resistant hard coating for severe service conditions
  • Available with high strength proprietary steel for increased torque capacity
  • Alloy Steel heat-treated, stress-relieved mandrel with rolled threads
  • Field replaceable nylon sleeve
  • Regular (104 °C) and high temperature (218 °C.) sleeves
  • Rotor is secured between two sucker rod or polished rod couplings
  • Designed to be rerun and rebuild is inexpensive
  • Available with or without attached coupling
  • Easy installation with power tongs and sucker rod manufacturer’s make-up card
  • Proprietary blends of sleeve materials provide maximum lubricity and wear life
  • Field proved and developed over 10 years of running history
  • Proprietary blends of sleeve materials provide maximum lubricity and wear life
  • Field proved and developed over 10 years of running history


Refer to the image below for PL5 Dimension Information:

*higher torque ratings available in the ToughTorq

More on Couplings

The basic function of all couplings is to transmit power, accommodate misalignment, and compensate for axial movement.

Selecting the right coupling depends on four basic conditions of shaft misalignment or movement:

  1. Parallel misalignment occurs when the two shafts do not share the same rotation axis. Their end faces may be parallel, but their center axes are laterally displaced with respect to each other.
  2. Angular misalignment happens when shafts are not parallel or coaxial. The misaligned angle of the shafts may be symmetrical or asymmetrical.
  3. End float occurs when either or both shafts display axial movement—meaning it moves in and out. A sleeve-bearing motor, for example, “floats” as the rotor hunts for the magnetic center of the winding. Thermal expansion and different shaft positions may also be a cause of temperature variation.
  4. Torsional flexibility is the torsional movement in planes perpendicular to the shaft axis. The cause of this is usually a torsionally flexible coupling absorbing and dampening these movements.

How to Maintain your Coupling

Maintaining your coupling is important for it to perform optimally and for safety reasons. Here are some tips on how to maintain your coupling:

  • Perform inspections to check for signs of wear or fatigue
  • Clean couplings regularly
  • Checking and changing lubricant regularly
  • Documenting the maintenance performed on each coupling and the date it was performed

Signs Your Coupling is Failing

After a time, your coupling will start to show wear. It is important to see the signs of a failing coupling so you can get a replacement promptly. Here are some signs that your coupling is failing:

  • Abnormal noises such as screeching, squealing or chattering
  • Excessive vibration or wobble
  • Failed seals indicated by lubricant leakage or contamination

Why Coupling Might Fail

Even the best couplings might fail. Some of the underlying causes include:

  • Improper installation: not installing your couplings properly mean that your coupling will not function properly, and this will lead to your coupling failing
  • Poor coupling selection: it is important to select high quality and the right couplings for your application.
  • Operation beyond design capabilities: Couplings may fail due to factors that aren’t related to the design.


Why Plainsman

Our quality policy statement is “we deliver superior quality products that meet customer expectations by being agile and efficient”.

We are dedicated to providing customers with the best possible service and maintain a large inventory at our Edmonton location.

We manufacture and distribute products for oilfield production, pipeline maintenance, construction and gas water distribution.

We are large enough to effectively look after our customer’s needs and we’re dedicated to providing the personal service and attention our customers deserve.

We are constantly seeking out new and better products and services to meet our customer’s requirements and the changing demands of the industry.


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