Model : S 11

Hinged Welded Spring Bow Centralizer

Eneroil’s hinged welded bow spring centralizer is a high-quality welded product that meets or exceeds API 10D specifications. These centralizers combine a very high restoring force with a very low starting force. The centralizers feature bow springs strongly welded to its end collars. This welded design provides excellent downhole durability. Premium quality bows made of a special alloy steel with uniform hardness provide optimum performance and excellent stand-off. The end collars are available in a latch-on design with a high-strength steel-locking pin for maximum structural toughness. With a choice of six different bow heights, a perfect combination for casing/open hole configuration can be achieved.
Furthermore, the installation of Eneroil’s welded hinged bow spring centralizers on the casing pipe is very convenient, as it requires only the placement of the two assembled halves on the pipe and the insertion of the pin in the end collar hinge. Additionally, the centralizer when unassembled makes a compact package, greatly reducing shipping cost.

Performance Features

  • Welded centralizers have more running force when compared to their non-welded counterparts.
  • Bows can be configured for any hole diameter with a choice of six standard bow heights for optimum starting and restoring forces.
  • The compatibility of the bows with various end collar sizes reduces inventory requirements and provides tremendous flexibility of casing and hole size combinations.
  • A high restoring force combined with a low starting force is achieved with all bow heights.
  • Bow springs are of high quality alloy steel, bent to shape and heat treated under controlled temperature / time cycles for consistent spring characteristics.
  • The bows provide an excellent standoff, which allows for an efficient mud and cement displacement.
  • End collars are of widened-design for greater frame strength and to prevent the bows from hitting the casing.
  • Hinge locking pins are made of high-strength steel for maximum structural strength.
  • Is able to centralise the casing pipe in vertical, deviated and horizontal wells.
  • Its high performance characteristics are combined with an easy field assembly.


  • Welded bow spring centralizers are available in sizes 2 ⅞" to 30”
  • Special sizes or combination can be made available on request

Recommended For Use With

  • Hinged Stop Collar – S-60
  • Hinged Stop Collar with Spiral Nails – S-61 / S-62
  • Stop Collar with Set Screws – S-63