1. Reasons for using a sandbox locking tool Our company's subordinate thermal processing division is engaged in the production of steel castings for more than 50 years. The sandbox joint box has always used the traditional lock box method, that is, the box and the box are welded by round steel, and the upper box is pressed with the pressure box iron. The disadvantage of the lock box method is that repeated welding and cutting will cause damage to the outer box mouth, shorten the service life of the sand box, and waste manpower and material resources. There are many drawbacks to this sandbox locking method, and a safer, more convenient and economical sandbox locking method should be sought. In addition, when using the box iron in the upper box, the influence on the quality of the casting has the following aspects: Please see the attachment for more details: AWWA Flange Standards differ from ANSI (American National Standards Institute) and ASME (American Society of Mechanical Engineers) certifications in a variety of ways, the most important being their specificity: AWWA standards evaluate properties that particularly affect potable water use, as opposed to broader industrial flange applications. AWWA Flanges,WNRF Flange,HDG Flange,AWWA C207 Flanges Shandong Zhongnuo Heavy Industry Co.,Ltd. , https://www.zhongnuoflange.com