A compressible steel washer manufactured with protrusions on one side, known as a direct tension indicator washer (DTI). When used with structural bolts the DTI is designed to compress to correlate to bolt tension.
The DuraSquirt® DTI is the same as other DTI washer except for the orange silicone that has been added to the welds under each bump. As the bolt is tighten the bump compress pushing the silicone to edge of the washer indicating to the installer the correct tension has been achieved.
Squirter DTIs are made and certified to ASTM F959. They are also covered in the Australian standard AS4100 steel structures for tension by use of direct tension indication device.
Direct Tension Indicator Washers FEATURES:
- Easier & Better than Turn-off Nut
- You don’t have to remember to stop turning at 1/3rd, 1/2, or 2/3rds turn. No match marking necessary.
- Better than a Twist-Off Bolt
- Tension control rather than torque control.
- No splined end to twist off and become a safety hazard.
- No problems caused by the splined end shearing off in torsion before the plies are together.
- Easier & Better than Calibrated Wrench
- You don’t have to establish and then check the torque resistance of bolts daily and for each lot and when your wrench condition changes.
- Works with All Bolt Lengths
- Even when the bolts are extremely short or long, DTIs show you when the correct tension has been achieved.
- Saves Erector Time
- Enables correct tensioning as fast as the wrench can be moved to the next bolt, because the operator can see when to stop.
- Establishes A Good Snug Point
- With DTIs, snug is partial bolt tightness without any or much silicone showing. The snug criteria becomes no squirt. The tight criteria becomes squirt.
- Visual Low Tech Tension Indicator
- The orange silicone is easy for erectors to see. No feeler gage except during calibration.
- Safe for Inspectors
- Once calibrated, because inspectors can easily see the orange squirts, they don’t have to climb out to all the connections or lug around a torque wrench to know the connection has been completed. And instead of sampling only some of the DTI’s with a feeler gage, DTIs allow virtually 100% inspection.
- DTI’s Approved
- DTIs are still made and certified to ASTM F959. FHWA pre-installation verification procedures, Research Council tests, and State DOT Quality Assurance procedures are unaffected.
- Extremely High Bolt Tension Avoided
- Erectors know when to stop tightening. Some applications prefer bolts tightened over a minimum, but not too far over. DTIs enable previously unavailable control.
Installation Method
The recommended installation is to position the DTI washer at the nut end of the assembly with the orange Squirt™ material facing towards the steel surface – seen in method A below. The assembly can then be tightened from the nut.
It is good practice to store all bolt hardware away from the elements prior to installation, preventing corrosion will reduce the effort required to tension bolts properly. The bolt threads and washer face of the hex nut can be lubricated to improve installation by reducing friction.
The hole detail in the steel work is critical to the bolt assembly and connection.
To know more about this products, kindly click the link below:
If you would like to discuss these products further, or how they can benefit your application, then please do give us a call.
For inquiries contact Hytec Power Inc. PH Distributor
We would also urge you to view Hytec Power Industrial department within www.hytecpower.com and http://ind-news.hytecpower.com/ where we have Hobson Engineering on some of the subjects touched upon above.
