508mm Rubber Lined Conductor Stringing Block with 20-60KN Rated Load for ACSR Stringing Block Pulling

508 Series Conductor Stringing Block with Rubber Lined Aluminum Sheave

The 508 series stringing block is built around a 508mm sheave that keeps the conductor bend radius large enough for ACSR and OPGW pulls without stressing the outer strands. Six sheave configurations let a single series cover single conductor pulls, three conductor bundles and five conductor bundles with the same frame geometry and mounting interface.

Product Overview

Each sheave is machined from aluminum or cast steel and fitted with a sealed bearing, so rolling resistance stays low over long pulls. The rubber lined version adds a vulcanised liner in the groove that grips the conductor without marking it, which matters on aluminium and on optical ground wire where surface damage can shorten service life. Frames are welded, straightened after welding and then painted, and every axle is checked for straightness before assembly.

508 series configurations

Dimensions and ratings are nominal. Confirm the exact model against the datasheet before ordering.

Design Features and Field Benefits

• Groove Geometry Protects the Conductor: The groove radius is matched to common ACSR and AAAC diameters and polished after machining, so the conductor sits on a smooth saddle instead of a sharp edge. This avoids strand nicking and reduces the chance of corona-producing surface defects.
• Sealed Bearings Cut Pulling Effort: Sealed deep groove bearings retain grease for the life of the block and keep dust out on site. Lower rolling resistance means the tensioner works at a lower setting for the same pull, which reduces wear on both rope and sheave.
• One Frame, Three Sheave Counts: Single, three and five sheave versions share the same frame and hanging point, so a crew can swap blocks without changing rigging hardware. Spare parts stay common across the series.
• Material Options for Different Budgets and Loads: Rubber lined aluminium suits conductors that must not be marked, cast steel suits the centre position on bundle blocks where loads concentrate, and MC nylon gives a light block for hand handling on distribution work.

Selection Guidance

• Match the sheave groove to the conductor diameter; an oversized groove lets the conductor flatten, an undersized one pinches it.
• Use three and five sheave blocks for bundle conductor pulls where all sub-conductors must be tensioned together.
• Confirm the required safety factor against your project tension before choosing the 20KN, 40KN or 60KN frame.

Typical Applications

• ACSR and AAAC overhead conductor tension stringing
• OPGW and earth wire installation
• Bundle conductor pulls on 110kV to 500kV lines
• Distribution line reconductoring

Quality Control and Delivery

Units are assembled in an ISO 9001 certified workshop. Frames are checked for sheave alignment and axle straightness, load bearing parts are inspected before assembly, and finished units are function checked before packing. Export packing is a plywood case with a moisture barrier, and a 12 month warranty covers manufacturing defects. Inspection records and, on request, third party load test certificates can be supplied with the shipment.

Frequently Asked Questions

For project specific configurations, drawings or inspection requirements, send the conductor size, rated load and destination port with your enquiry.