The wire threaded insert (or screw thread insert) was first used by the aircraft industry in the 1930s to accommodate the use of lighter and weaker aircraft materials to produce larger, heavier aircraft. Wire threaded inserts enabled the aircraft industry to use lighter materials without sacrificing durability.
To comprehend the development of wire thread inserts, let's read a narrative-
KSB, founded in 1871 and situated in Frankenthal (Rhineland-Palatinate), is one of the world’s leading manufacturers of pumps and valves. With its own production sites, sales companies and subsidiaries, the group is represented across the globe. During 2013, 16,000 employees achieved a total turnover of more than two billion euros. The products are applied in several industries in order to transport or isolate liquids, also in an aggressive, explosive or toxic form, safely. The technical highly productive and extensive pumps portfolio is especially used in power plants. These power station pumps are appropriate for many different applications, e.g. conveying of boiler feed water, condensate, cooling water and coolants or for recirculation of boiler water.
High reliability and maintenance-friendly constructions are important requirements for pumps in power stations. During the entire operation period, these pumps need to be inspected reliably and removed easily. Furthermore, the disassembly of large service gates for inspection purposes is an essential aspect. The material selection of the components is severely limited due to certain guidelines and customer demands. Based on operational influences, the risk of a difficult disassembly or even a seizing of the screw connection could occur. This could lead to unscheduled, additional work during maintenance and inspections and at worst cause delays in recommissioning the power station.
The solution with Böllhoff
In order to overcome the challenge of a failure-free pumps removal for maintenance, KSB uses reliable HELICOIL thread technology. A HELICOIL thread insert in the dimension M 125 x 4 x 166 is screwed into the pump housing by using a purpose-built installation tool to enable thread reinforcement. Consequently, seizing is avoided. The pump can now be easily removed and afterwards mounted again. The pump housings, weighing approx. 30 t, comprise in each case 16 threads with HELICOIL thread inserts.
1954 – a very important year
In Germany, Böllhoff started the HELICOIL production and thereby created product history. These thread inserts create high-strength fastenings in metal materials of low or high shear strengths. The newest generation of the HELICOIL plus technology allows a simplified installation due to an easy handling. Since more than 65 years well approved, the HELICOIL is an accredited construction element. There is hardly any requirement regarding the thread technology that could not be solved. ”The use of the HELICOIL thread technology provides an uniform load distribution in the thread, increases the pump servicing and contributes to a higher customer satisfaction.“ Denis Yücel, MBA Eng., Development engineer for large pumps.
Although common generic name is screw thread insert (STI) and wire thread insert but above you read a word “HELICOIL” which is the most famous word used by many user and this is a registered brand name of Böllhoff. Since Helicoil has been in business for more than 60 years and has established itself as the leading manufacturer and supplier of wire thread inserts globally, these wire thread inserts have recently been referred to as Helicoil inserts.