DuraSquirt® Direct Tension Indicators (DTIs) are bumpy washers that show how much bolt stress, or tension, has been developed in a fastener. They function independent of torque values and nut factors and indicate load directly when a nut is torqued along the threads of a stud or bolt. Once the induced tension/bolt stress has reached a predetermined minimum, the orange DuraSquirt® DTI material is expelled and tightening effort is stopped. The tool operator moves the tool to the next fastener, in the joint, and repeats the tightening & orange material expulsion process, until all bolts within a joint have been tightened.
The DuraSquirt® DTI Sigle Pass Flange System consists of a kit of numbered DTIs, calibrated to account for elastic interactions between each bolt. Like our structural DTIs, bolts are tightened until DuraSquirt® DTI indication media appears. The only difference is the DTIs must be placed in numerical order along the flange, each quadrant snugged, and then tightened in numerical order.
DuraSquirt® DTI Flange Systems are only designed to work with:
- ASME B16.20 Dual ring spiral wound gaskets.
- ASME B16.5 & ASTM A105 weld neck, raised face flanges.
- ASTM A193 B7 studs.
Each DTI kit is composed of the same number of DTIs as there are bolts in the flange. Kits should be ordered in the same quantity and at the same time as gaskets