Radial Fit Bolts

THE INNOVATIVE, TECHNICALLY PROVEN SOLUTION

Approved by all the major Classification Societies, the primary application of Pilgrim Radial Fit Bolts is to connect the propulsion shaft equipment and shaft sections at the face-to-face coupling flanges.

Unlike traditional shrink fit bolts, Pilgrim Radial Fit Bolts are designed to be installed and removed whilst in a clearance condition.

During installation the clearance condition eliminates the need for any hazardous shrinking operation required with an oversize traditional bolt.  At the time of removal, the same clearance condition makes withdrawal of the bolt easy.

The interference fit achieved during the installation of a traditional shrink fit bolt often varies.  In some cases the bolts may be easy to remove.  However, it is very common for either the bolt, flange or coupling hole to be damaged during the removal procedure, adding expense and potential for delay.

Installation and removal of the Pilgrim Radial Fit Bolt is extremely fast, reliable and predictable allowing resources and engineering time to be accurately forecast. Depending upon access and bolt size a typical installation or removal time for each bolt is between 10 to 15 minutes.

BASIC PRINCIPLES OF OPERATION

Consisting of a tapered bolt, an internally tapered sleeve and two securing nuts the Pilgrim Radial Fit Bolt is installed and removed with minimum effort using the special tools and equipment supplied by Pilgrim International.

When the tapered bolt is hydraulically drawn into the tapered sleeve, the sleeve is forced to expand inside the hole forming a pre-engineered interference / pressure fit. The bolt is then hydraulically tensioned to provide a pre-determined secure clamping force across the flanges.

Removal is achieved by relieving the clamping force and using oil injection to separate the bolt and sleeve. The most important factor here is that, when the sleeve and bolt are separated, the sleeve returns to its original clearance condition allowing easy removal of both the bolt and sleeve. (See installation / removal section for more details).

BENEFITS TO SHIP YARDS

  • Faster installation
  • Safer, easier handling due to elimination of freezing
  • Fast, easy removal and re-installation to correct shaft line mis-alignment
  • More accurate, predictable and secure connections
  • Pre-engineered interference fit and clamping loads across flanges

BENEFITS TO SHIP OWNERS, OPERATORS AND MANAGERS

  • Accurate, secure flange connections reduces flange separation and hull vibration
  • Faster tail shaft surveys and shaft-line disconnections
  • Bolts fully re-usable for entire life of vessel
  • Eliminates problems damage and delays associated with conventional bolt removal
  • Eliminates any hidden costs or time factors
  • Operating time maximised
  • Reduced maintenance budget
  • Makes planning of central docking schedules easier

Click here for diagram of Installation

Click here for diagram of removal

Click here for radial fit bolt datasheet