Pre tightening bolt

Pre tightening bolt to replace the existing six angle nut. Only hand tools can be installed and disassembled for any size of bolts. Safe, accurate and economical! We have a wide range of standard series, as well as an unlimited capacity to create special designs to meet your unique needs.

Pre tightening bolt is a new technology for the bolt and bolt. Locking large size bolt, preload bolt - simple, cost-effective. No need for professional and heavy tools, your connection parts can be accurately locked. Pre tightening bolt OEM manufacturers to improve the design of the bolt to ensure reliable operation, simple maintenance process, useful for the entire life cycle of the bolt connection.
 

Features are as follows: 

The mechanical benefit is obvious, the accurate pre tightening force, the stress releasing function, the increase of the bolt connection flexibility, the saving of the fastening time, the adaptation to the high temperature and the dynamic load.

 1 the Multi cone bolt (nut) is composed of a round nut with a plurality of push bolts and a super hard washer. When in use, the super hard gasket is sheathed in the screw, and then the nut is screwed off by the hand, and the contact to the super hard gasket can be used. Fastening is only through the manual wrench to complete, completely abandon the hydraulic wrench, hydraulic stretching, electric heating and other traditional methods.

2 the pre tightening force of the multi cone bolt is proportional to the number and the diameter of the bolt, and the error of the pre tightening force of the multi cone bolt is only about 5%. Accurate preload is a stable, durable and reliable guarantee for bolt connection system.

3 stress release function is another characteristic of multi cone bolt, interaction and pushing the main bolt preload, the bending moment in the super nut, the bending moment appears as circumferential stress, resulting in super nut for circumferential stress. The circumferential stress makes the diameter of the bottom of the super nut increase, while the diameter of the upper diameter is reduced. This expansion phenomenon began to release the stress concentration and improve the static load and prevent thread seizure (metal adhesion effect).

4 multi cone bolt can make the bolt increase 50%-100% elastic connection fastening system, after the completion of the load distribution to each thread (the relevant test proved the traditional bolt about 1/3 load in the first teeth, 3 teeth under load 70%). At a certain temperature the creep is continuous and uniform, so this extra increase of elasticity can not only extend the service life of the bolted connection under a wide range of temperature alternating conditions, but also play a role in preventing loosening.

5 the top bolt of the multi cone bolt is very small in diameter and needs little torque, so it can be easily completed by using the hand tool. In the heat exchanger cover and flange bolt fastening and need more occasions, can be the first to use ordinary pneumatic wrench, many people at the same time, the manual calibration of torque wrench torque, it can greatly improve the working efficiency.

More than 6 top cone bolt in equipment alternating thermal or dynamic load, multi cone bolt in a given torque according to the manufacturer after fastening, the deformed, the deformation of the connection is a kind of energy storage, similar to the use of the lengthened screw bolt to improve elasticity, it can absorb heat due to temperature changes or because of the different thermal expansion coefficient material to generate excess load. In the case of not increasing the length of the screw, the bolt connection has the function, and the use of the multiple cone bolt can be used to increase the effective length of the 2-4 bolt.

Patent certificate	Operation principle
			1 at most by tightening the screws, the jacking force is strong (Zhou Xiang). The top thrust is directly on the hard washer. The friction diameter of the push screw is small, so the high thrust force can be realized by the relatively small torque. 2 the load is passed to the nut on the main thread that has been installed manually. 3 rigid gaskets used to transfer thrust, while protecting the flange surface. 4 many top push screws (Zhou Xiang) top thrust and the reverse force of the main bolt head together on the flange produced a strong clamping force. 5 The top thrust (axial) of the 5 push screws creates a force of the same size on the main bolt.
		CW type: Suitable for -40 C to 250 C equipment connection, such as mining machinery, boiler feed pump, circulating pump, heat exchanger, coupling, etc.
		ZW type: The device is suitable for the connection of the equipment, such as a steam turbine, an engine, a high temperature pump, a compressor, etc., at 250 degrees C to 350.
		GW type: The device is suitable for the connection of devices over 350 degrees Celsius, such as high temperature reactor, high temperature steam turbine and so on.
		JW type: Suitable for space limited connection, such as hydraulic cylinder, shaft bracket, etc.
Partial performance
High temperature and high pressure reactor for hydrogenation unit		Reciprocating compressor for hydrogenation unit
High pressure heat exchanger of hydrogenation unit		Reciprocating compressor for hydrogenation unit
High temperature reactor for reforming unit		Compressor piston lock