7.2.2 Insulating Wrench
1.Structure and Function of Insulating Wrench
Insulating wrenches are tools used to tighten hexagonal,square screws and various nuts.Insulating wrenches are made of tool steel,alloy steel or malleable cast iron.Insulating adjustable wrench is mainly composed of fixed wrench lip,adjustable wrench lip,worm gear,shaft pin,handle,etc.,as shown in Fig.7-20.Insulating adjustable wrench is a tool for tightening or loosening angular screws or nuts.The size of the wrench opening can be adjusted by rotating the worm wheel of the adjustable wrench.The fixing and forming of the wrench opening of the insulating solid\wrench cannot be adjusted,and is only applicable to screws of the same specification,as shown in Fig.7-21.
Fig.7-20 Insulating Adjustable Wrench
Fig.7-21 Insulating Solid Wrench
2.Basic Types and Technical Specifications of Insulating Wrenches
Insulating wrenches commonly used in live working of power transmission and distribution lines generally include adjustable wrenches,fixed wrenches and socket wrenches.
There are three types of insulating adjustable wrenches:200mm,250mm and 300mm(English 8in,10in and 12in).According to the size of the nut,choose the insulating wrench of appropriate specifications,in order to avoid damage of too large wrench to the nut;Or the wrench is damaged due to too large nut.
3.Inspection of Insulating Wrench Before Use
(1)Check whether the handle part of the insulating wrench is cracked and damaged,and whether the insulating part is aged.(https://www.daowen.com)
(2)Check whether the opening of insulating adjustable wrench can be flexibly adjusted.
4.Usage of Insulating Wrench
(1)When using,insulating adjustable wrench with appropriate specifications shall be selected according to the shapes,specifications and working conditions of screws and nuts.
(2)The opening size of the insulating adjustable wrench can be adjusted within a certain range,so screws and nuts within the opening size range can generally be used.
(3)For insulating movable wrenches,it is not allowed to use large-sized wrench to tighten screws of smaller size,which will break the screws due to excessive torque;the opening shall be adjusted according to the size of the opposite side of the hexagonal head of the screw or the hexagonal head of the nut,and the clearance shall not be too large,otherwise the head of the screw or the nut will be damaged,and it will easily slip off,causing injury accidents;the fixed jaw shall be subjected to the main acting force,the wrench handle shall be tightened towards the operator,not pushed forward,and the wrench handle shall not be lengthened arbitrarily;wrenches shall not be used as hammering tools.
5.Precautions for Storage of Insulating Wrench
Insulating wrenches shall be stored in a dry and well-ventilated tool warehouse,and shall be numbered and placed on shelves at fixed points.The storage of insulated wrenches is shown in Fig.7-22.
Fig.7-22 Storage of Insulating Wrench
6.Preventive Test of Insulating Wrench
The insulation part of the insulating wrench shall be subjected to high voltage power frequency withstand voltage test on a regular basis with a test cycle of 1 year.