FAQ About Rigid Centralizers

ZHENGZHOU, JULY 15,2016 - FAQ means frequent asked questions. These questions about rigid centralizer is common and also what our customers often ask and care about. If  these FAQ are listed on line, they will save time for customers and then complete the order in the shortest time.

Although casing centralizers including bow spring centralizer and rigid centralizer are manufactured according to API 10D standard, the API(American Petroleum Institute)do not give detail requirements like material, heighth, vane quantity, construction thickness and so on.

Now some FAQ are listed as follows, you can contact us directly if it is not available on line.

1.What is the material for rigid centralizers?
The rigid centralizers are solid construction, made of mild steel, aluminum alloy, zinc alloy, composite material. Mild steel is stronger than aluminum alloy, zinc alloy or composite, but aluminum alloy and zinc alloy will gall and become sticky at high speed and elevated temperature. The composite is composed by nylon and fiber glass whose features are high temperature resistant and wear resistant.

2.The vane of rigid centralizer is welded or integrated with rigid centralizer?
The vane is integrated with rigid cnetralizer, because the rigid centralizer is designed and manufactured by mold and casting process, it is better to save processing time and reduce the blowhole quantity on centralizer construction. Sometimes the welded vane will fall off if there are something wrong with welding procedure.

 

3.Can the rigid centralizer be coated to improve the friction factor?
The powder coating, paint coating or Teflon-like coating are available for rigid centralizer, they provide an extremely low friction factor again open hole or rough casing pipe.

 

4.Why the spiral vane is often used instead of straight vane?
Straight vane only provides standoff while rigid centralizer provide more effective standoff and fluid swirl, the 45 degree angle spiral vane will provide maximum fluid swirl and remove the maximum mud from around the casing in any hole.

 

5.How much is the best vane width?
The standard vane on has an best width to provide sufficient support area. A wider vane means less by-pass area, higher pressure drop across the turbulator, and higher pump pressure which could result in formation breakdown during the cement job.

 

6.Why use set screws?
The rigid centralizer will be tightened the casing by setscrews to get much more  holding force. The setscrew will have 50000 pounds of axial load without sliding on casing according to test.

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