Hydraulic torque wrenches produce up to 58,000 ft-lb
July 28, 2010 by KRemington
Filed under Fastening-Joining for Wind Power
Laser engraved torque chart on the nose of the tool means no more searching for paper pressure charts.
The SD-Series is a range of square drive, hydraulic torque wrenches. The one piece body housing offers rigidity, strength, and durability in a lightweight form. The series torque output ranges from 1,722 Nm (1,270 ft-lb) to a staggering 78,625 Nm (58,000 ft-lb). The series from Tentec offers a selection of options such as reaction arms, which guarantee a reaction-point solution no matter how unusual the bolted application. Most reaction arms feature a sturdy “release button” built within the reaction arm housing and replaceable wear pads. A few other features include:
- Reaction arm release button, protected within the reaction arm housing
- Replaceable wear pad protects the reaction arm.
- Long reaction arm allows for reaction on most applications
- “Push through” square drive allows switching from loosen to tighten
- Anti-backlash mechanism provides hands-free operation
Wind Turbine Tools Inc
Plating protects fittings against corrosion
July 28, 2010 by KRemington
Filed under Condition Monitoring, Hydraulics, Maintenance, Mechanical Components, Uncategorized, Wind Power News
A proprietary plating gives hydraulic fittings protection against red rust. This helps users avoid the cost of corrosion which is calculated in terms of possible leak points and replacement fittings, along with potential lost sales stemming
- Parker TFD fittings and those from five major competitors were exposed to neutral salt spray test ASTM B117. One competing fitting showed red rust upon reaching the current SAE requirement of 72 hours while two other fittings exhibited red rust upon reaching the 96 hours benchmark, thus falling short of the proposed new requirement. The two remaining competitor fittings showed red rust after 240 hours. It is possible that in real-world applications, replacement of some or all of these fittings would be necessary, with the exception of the Parker TFD fittings.
from poor product perception. The TFD fittings, from Parker Hannifin Corporation’s Tube Fittings Division (TFD), could be part of any leak-free, well-functioning hydraulic system.
TFD fittings withstand harsh operating environments, particularly those that promote the rapid onset of red rust. Iron oxide signals oxidation and deterioration of the fitting base metal, which can degrade the fitting and compromise performance. Although the presence of red rust does not necessitate replacing a fitting, it can undermine users confidence in the integrity of the equipment on which it is installed.
In a recent salt spray test conducted by an independent test facility, the Miami Valley Materials Testing Center, TFD fittings remained free of red rust after 480 hours exposure. This significantly exceeds both the current SAE requirement of 72 hours and the proposed new SAE requirement of 96 hours of salt spray without red rust.
Parker Tube fittings Division
Electric torque gun shortens longer hydraulic jobs
June 8, 2010 by Kathleen Zipp
Filed under Policy
One maintenance company’s standard procedure for rechecking rotor blade bolts was to loosen then re-torque the 54 bolts on each of about 200 turbines. That’s a total of 10,800 blade bolts and a time consuming task. Some turbines require the task at three months after commissioning, and again in one year. One crew’s previous method for doing so used hydraulic wrenches. Although standard tools in the wind industry, they are cumbersome and work slowly. What’s more, bolt torque is usually determined by monitoring a pressure gage, which makes accuracy questionable.
Specs for the operation say to loosen each blade bolt and retightened to 258 ft-lb. Then each bolt is marked in a particular manner and turned an additional 120 degrees. The marking shows the angle has been completed.
E-RAD electric torque guns come from New World Technologies Inc, Abbotsford, B.C., Canada. Model 2000 has a 1-in. square drive that can deliver from 250 to 2,000 ft-lb. The unit is less than 13.25-in. long and comes calibrated with a control box, 15-ft of cable, and a standard reaction arm. The unit delivers smooth continuous torque at 10.5 rpm, a significant increase in speed over hydraulic wrenches. Noise levels, at 70 dB, are lower than those for hydraulic versions.
When the crew chief started looking for a more efficient method, the suggestion came in to try an electric torque gun. One version of such a tool, the E-RAD 2000, was recommended by a representative from Alltite Total Bolting Solutions (alltite.net). “The device applies torque with ±3% accuracy and ±2% repeatability, and because it is electric, it can store the torque applied to each bolt in a file that can be downloaded later,” says John Smith, Alltite CEO.
The E-RAD version of an electric “pistol grip” torque gun is manufactured by New World Technologies Inc (radtorque.com) and is intended for high torque and angle measurements. “The gun uses an AC Servo brushless motor coupled to a patented 490:1 gear multiplier to generate the high torque,“ says New World Application Engineer Curt Kehler. “The E-RAD operates by precisely measuring and controlling the current output of the ac servo motor. This precise measurement and control allows for high degree of accuracy and repeatability. An internal CPU stores a torque-versus-current calibration curve so that when the motor reaches a required torque as identified by electrical current, the motor shuts off. In house tests show the gun gets better than ±1% of a required torque value.” To control the application of the additional angle, the gun’s ac servo motor drives an encoder which tracks and records 4,096 points on a 360° rotation of the motor drive.
The maintenance company ordered the torque gun with an option to define torque and the angle sequence. The defined settings are stored using an 8-channel selector switch on the gun’s control box. All defined settings can be locked out using a removable key so unauthorized personnel cannot change them. Basic data collection, which is included, records the set torque, set angle, and provides the actual torque applied and angle turned. To eliminate of user error, an LED indicator on the tool handle displays and a red light to indicate an incomplete torque cycle and a green light when the torque cycle completes.
The maintenance firm says the electric gun provided a return on investment within the first month because its speed allowed the crew to finish the maintenance job in half the time usually spent, and then it took only half the labor of a hydraulic wrench.
