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Metrology Stab and Receptacle

LBL transponder accessory

Engineered for

Structure
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Overview

Designed for precision survey and construction

Designed for use with Compatt 6 and Gyro Compatt 6 (including plus variants), the metrology stab and receptacle enables LBL transponders to precisely and repeatedly install on subsea structures.

Overview

With a high manufacturing tolerance combined with a pop-up ‘tell-tale’ flag that provides visual confirmation the transponder is precisely docked, our stab and receptacle saves times and improves the accuracy of subsea construction.

Using our stab and receptacle, the traditional method of rotating of a stab in a hub during metrology operations to determine stab-to-receptacle slop, can be eliminated. With this time consuming task removed, acoustic metrologies have the potential to be completed in less than six hours.

The tolerance of the design allows for 0.1° for heading and 0.01° for pitch/roll which is the same quoted error of a calibrated Gyro Compatt 6. This improves the results of the metrology or other positioning tasks and reduces the need for error determination of the stab/receptacle.

At a glance

  • Allows you to accurately align transponders on structures
  • Perfect for installation during metrology campaigns
  • Allows transponders to be quickly removed and re-installed using ROV
  • Two stab variants available to bolt onto either Inclinometer Compatts or Gyro Compatts
  • Can be fitted on the back deck using existing hole patterns
  • Tell-tale indicator confirms the stab is fully docked into the receptacle

The receptacle is designed to bolt into the eight bolt hole pattern of the industry standard 8” AWWA Class D flange. This allows the user to either bolt this flange onto the structure or to provide bolt holes in the structure itself. After dimensional control techniques to determine the relationship of the bolt holes in relation to the structure points of interest (jumper hubs, CRP, spool flanges, etc), the receptacle can be bolted in with known offsets to these points. This allows fast and precise inferred metrology to one or multiple hubs or flanges from a single receptacle.

The receptacle features a 45° cone in which the stab sits. This reduces the possibility of debris building up on the interface between the two and allows for a more precise connection due to the point of contact being exactly circular regardless of any small expansion/contraction effects.

The stab also features an alignment bar rather than alignment pins to aid docking and provide superior heading alignment. An O-ring on the stab shaft assists in ensuring the two are precisely mated.

Specifications table

Feature Receptacle Type 8300-250 Stab Type 8300-240 Stab Type 8144-150
Compatible Products Stab 8300-240 & 8144-150 Inclinometer Compatt 5 & 6 Gyro Compatt 6
Outside Diameter 343 mm 185 mm 185 mm
Maximum Height 100 mm 164 mm 164 mm
Stab face to Flange Face 76 mm 76 mm 76 mm
Mechanical Construction Acetal (Delrin) Super duplex stainless steel Super duplex stainless steel
Bolt Hole PCD Removable n/a n/a
Tell-tale Removable n/a n/a
Attitude Tolerance Heading 0.1°, Pitch / Roll 0.01° Heading 0.1°, Pitch / Roll 0.01° Heading 0.1°, Pitch / Roll 0.01°
Alignment Quadrants Four (0°, 90°, 180°, 270°) Four (0°, 90°, 180°, 270°) Four (0°, 90°, 180°, 270°)

Did you know?

There are two stab variants available to be used with either Compatts or Gyro Compatts