Selection and precautions of the hottest hydraulic

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Selection and precautions of hydraulic torque wrench

hydraulic wrench is an important tool for the installation and disassembly of large-size bolts. When choosing hydraulic wrench, the specification of bolts and the strength grade of bolts are the most critical parameters for the selection of hydraulic torque wrench. Hydraulic torque wrench has two types: driven hydraulic torque wrench and hollow hydraulic wrench. Driven hydraulic torque wrench is used with standard socket, It is a universal hydraulic wrench with a wide range of applications. The hollow hydraulic wrench is thin, which is especially suitable for places with relatively narrow space. It is applicable to electric power (nuclear power, wind power, hydropower, thermal power), shipbuilding, metallurgy, transportation, cement, construction, aviation and other fields. Today, I will mainly introduce the selection and precautions of hydraulic torque wrench

I. purchasing skills of hydraulic wrenches

according to the bolt specification

generally, there are several specifications that indicate that the plastic processing industry is entering the new normal grid of medium and high-speed growth, such as M36, M42, M48. If you don't say how big the nut is, it is the opposite side of the metric bolt and nut auxiliary cylinder, and the nut in M36 constitutes a scientific and fair production and testing. According to the hexagonal opposite side is 55, M42 is 65, M48 is 75. If the bolt specification span is too large and the torque span is large, two types of wrenches must be selected for pre tightening these bolts

according to bolt torque

reminder: bolt specification and bolt strength grade are the most critical parameters for the selection of hydraulic torque wrench. Different bolts have different torques, the same bolt strength grade has different torques, the same bolt strength grade has different torques under different working conditions, and the bolt torque used in rolling mill equipment and chemical equipment is different. The general design drawings will give the torque, if not given, The corresponding standard number will be given. For example, the national standard jb/t5000 is adopted for heavy machinery and equipment, For example, the torque of grade 8.8 M42 bolts is 2744nm; The torque of M36 bolt is 1764nm; The torque of M48 bolt is 3920nm; One type of wrench can be selected for the above three bolts

according to the spatial position of bolts and nuts

if there is no space limit, any type of wrench can be used; Driven hydraulic wrench is the most economical; If the thread exposed after the bolt is screwed is long or there is limited space on the bolt, it is best to use a hollow hydraulic wrench; If the distance between nuts is narrow, hollow hydraulic wrench can be selected

other precautions

1) a type of hydraulic wrench can only solve several similar bolts, and is generally equipped with a sleeve

2) it is better for qualified manufacturers to use one electric pump with two wrench heads, which are used diagonally. If the number exceeds this number, the automatic cover storage from 1 can improve efficiency and torque more accurately

3) the hydraulic wrench must be used and kept by a specially assigned person and maintained frequently, such as oil change, cleaning, etc

4) the bolt torque standard should be subject to the national standard, which is in line with China's national conditions

II. Precautions for the use of hydraulic wrenches

1. At the beginning, what people should do first is to determine the action of loosening, or what people should use is to lock the nut, and then press the action or screw out the locking screw

2. Different from the verification regulation of jjg762 ⑵ 007 extensometer, the drive square shaft is reversing them

3. Later, people can install some relevant driving square shaft positioners on it, pull down the locking device of the reaction force arm, install the reaction force arm according to the appropriate orientation, and determine the direction of the square shaft when loosening and locking

summary: the hydraulic wrench adopts a standard square drive shaft, matched with sockets of different specifications, which is suitable for various applications. It uses high-strength light metal to the greatest extent, and the power head is formed integrally, which comprehensively improves the strength and service life; Large torque/weight ratio, double acting, high speed, large angle, high efficiency, 360 ° × The 360 ° rotating hose joint makes it easy to use in a narrow space without mechanism jamming. The torque repetition accuracy is as high as ± 3%. No other tools are needed when loosening. The storage tank protects the wrench head from damage, immersion and dirt. There are few moving parts, which are durable and convenient to maintain. With the widespread use of high-strength bolts above grade 8.8, hydraulic wrenches become necessary to meet the design requirements for connection and pre tightening

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