DEVICE FOR MONITORING STRENGTH OF PINS (BOLTS) Russian patent published in 2016 - IPC G01N3/02 G01N3/08 

FIELD: machine building.

SUBSTANCE: invention relates to non-destructive testing of materials and items and can be used in machine-building industry during assembly of units and parts of body items and during operational check of residual strength of fasteners. Device consists of a rod inserted into a through hole made parallel to the axis of a pin or bolt, or inserted into a slot cut along the pin from the outside to the depth providing for the rod penetration into the body of the pin (bolt) behind the depth of the inner diameter of the thread; at that, one end of the rod is fixed relative to one edge of the hole or slot (threaded end fixed with lock nuts is possible), and the second protruding part of the rod is bent at an angle of 90° and in the initial state is adjacent to the end of the pin (bolt). Evaluation of the strength of the pin (bolt) is performed based on the value of deflection of unsecured end of the rod, which is an indicator of a stretch, relative to the end of the pin (bolt) to an angle α, limit value of which is set based on the pin (bolt) stretching to destruction on a breaking machine, applying via the pin nuts (or the bolt head and nut) a load, when the distance between the nuts on the pin or the distance between the bolt head and the nut is equal to the total thickness of connected flanges and the value of a gap between them in the article.

EFFECT: operative monitoring of residual strength of pins (bolts) in flange joints of pipelines and valves, which allows to reduce a probability of manmade disasters and costs for their prevention and elimination.

4 cl, 4 dwg