Interesting things about Bolt Tensioning

What is Bolt Tensioning
Tensioning is the direct axial stretching of the bolt to achieve preload. Inaccuracies created through friction are eliminated. Massive mechanical effort to create torque is replaced with simple hydraulic pressure. A uniform load can be applied by tensioning multiple studs simultaneously.

Tensioning requires longer bolts, and a seating area on the assembly around the nut. Tensioning can be done using detachable Bolt Tensioners or Hydraulic Nuts.

* Preload (residual load) = Applied Load minus Load Losses *

What is Load Loss
Load loss is a loss of bolt elongation depending on factors such as thread deflections, radial expansion of the nut, and embedding of the nut into the contact area of the joint. Load loss is accounted for in calculation and is added to the preload value to determine the initial Applied Load.

The preload depends on Applied Load and Load Loss (load loss factor).

Manufacturer's rating of pressure and load are maximum safe limits. Good practice encourages using only 80% of these ratings!

Tensioning Operation

Tensioning permits the simultaneous tightening of multiple bolts; the tools are connected in sequence via a high-pressure hose assembly to a single pump unit. This ensures each tool develops the exact same load and provides a uniform clamping force across the joint. This is especially important for pressure containing vessels requiring even gasket compression to affect a seal.

General Procedure

Step 1: The bolt tensioner is fitted over the stud
Step 2: Hydraulic pressure is applied to the tensioner which then stretches the stud
Step 3: The stud's nut is wound down against the joint face
Step 4: Pressure is released and the tool removed

The bolt behaves like a spring, when the pressure is released the bolt is under tension and attempts to contract, creating the required clamping force across the joint.

Less than 100% Tensioning

Not all applications allow for the simultaneous fit of a tensioning device on each bolt, in these cases at least two tensioning pressures are applied. This is to account for a load loss in those bolts already tensioned as the next sets are tightened. The load losses are accounted for in calculation and a higher load is applied to allow the first sets to relax back to the target preload. 



Set-up using a 100% tensioning procedure
All bolts are tensioned simultaneously.

Set-up using a 50% tensioning procedure
Half the bolts are tensioned simultaneously, the tools are relocated on the remaining bolts and they are subsequently tensioned

10 Interesting Things About XLCT torque wrench

10 interesting things about XLCT are as following-

1.It provide torque from 329 Nm To 42005 Nm.

2.The most used limited clearance torque wrench in the world.

3.HYTORC's patented In-Line Reactor permits the use of drive extensions, something no other  hydraulic wrench is capable of.

4.HYTORC-XLCT provides continuous turning speed and precise power delivery to the nut in all  applications.

5.HYTORC-XLCT is equipped with a 360x360 degree Uni-Swivel so there is literally no hose kinking  and the tool can be applied even in the most confined areas.

6.Build in withstand the rigors of daily use in heavy industry.

7.Versatile for use with hex, 12 point, castle nut sockets etc.

8.Eight models with torque output upto 59110 ft-lbs.

9. Uni-swivel technology for free movement & positioning of tools & hoses.

10.Available with square drive conversion link for use with hex and allen sockets.

Operations-

Connecting the System
The wrench head and power pack are connected by a 10,000 PSI operating pressure (40,000 PSI burst) twinline hose assembly. Each end of the hose will have one male and one female connector to assure proper interconnection between pump and wrenchheads.
As with other HYTORC models, if the square drive extends towards the right, the tool is set to tighten; if towards the left, its set to loosen. To change drive direction, press in on the drive retainer button, remove drive, place in opposite direction, and replace retainer, insuring it is secure.

TORQUING (tightening) with the XLCT Series and a Square Drive
Place the tool and the socket on the nut, making sure that the socket has fully engaged the nut and that the square drive is fully into the socket. Make sure the reaction arm is firmly abutted against a stationary object (i.e., an adjacent nut, flange, equipment housing, etc.).
By pushing down on the remote control button, the tool’s cylinder will extend and the reaction arm will contact its reaction point. Continue to hold down the button as the socket turns. When the hydraulic cylinder inside the tool is fully extended, the socket will no longer turn, and you will notice a buildup of pressure to the point where the pressure was preset prior to applying the wrench (See SETTING TORQUE).

IMPORTANT: This buildup of pressure after the cylinder is extended DOES NOT INDICATE that this pressure (torque) is being applied to the bolt. It only indicates that the cylinder is fully extended and cannot turn the socket further until the tool automatically resets itself.
Releasing the remote control button will retract the cylinder, and the tool will automatically reset itself. Each time the cylinder is extended and retracted, it is called a cycle. Successive cycles are made until the tool “stalls” at the preset PSI/Torque with an accuracy of ±3%.
IMPORTANT: ALWAYS ATTEMPT ONE FINAL CYCLE TO INSURE THE “STALL” POINT HAS BEEN REACHED.
Should the tool “lock on” after the final cycle, push down on the remote control button once more (to build pressure) and while maintaining this pressure, pull back on the reaction pawl release mechanism. Releasing the remote control button while continuing to hold back on the release mechanism will allow the tool to be removed easily.

Loosening Procedures
First, set the pump to 10,000 PSI. Set the tool for loosening and attach the socket. Make sure the reaction arm abuts squarely off a solid reaction point. Press and hold the remote control button down. Pressure will build up as the socket begins to turn. When the cylinder is fully extended, the socket will no longer turn. Release the remote control button, the cylinder will automatically retract. Repeat this process until the fastener can be removed by hand.
NOTE: If the bolt does not loosen using the above procedure, it is an indication that you will require the next larger size tool to loosen the bolt.

Applications-

It is extensively used in Petrochemical, Railway, Steel, Cement, Power Industry.

Why We Love Hydraulic Vertical Lifting Wedge

The Equalizer™ range of patented VLW18TE hydraulic & VLW18TI Integral Hydraulic Vertical Lifting Wedges has been developed to assist in the lifting of heavy equipment when access is restricted.

 BENEFITS

1.Require An Access Gap Of 9.5mm (0.37") And Will Provide A Lifting Force Of 18T.
2.To Assist In The Lifting Of Heavy Equipment When Access Is Restricted.
3.Recommended To Be Used In Pairs
4.Optimised reconfiguration time when vessel is docked
5. Sufficient lifting capacity for both tensioner & frame
6 Safe, controlled raising and lowering
7 No additional fabrication or modification to frame
8. Detailed step-by-step storyboard for each stage.

The EQUALIZER VLW18TE and VLW18TI hydraulic vertical lifting wedges will generate 18 Tons (180 kN) lifting force from 10,000 psi (700 bar) of hydraulic pressure. The tools require a minimum access gap of 9.5 mm(0.37)on the first step & will left vertically.Using two VLW18TE/TI wedges will allow a lift of 36 Tons.Using four VLW18TE/TI wedges will allow a loft of 72 Tons.

1.VLW18TE External hydraulic vertical lifting wedge

The VLW18TE Vertical Lifting Wedge uses an external hydraulic hose & hand pump allowing the tool to be operated a short distance away.

2.VLW18TI Internal hydraulic vertical lifting wedge

The VLW18TI Integral Vertical Lifting Wedge has a built in hydraulic pump allowing the tool to be used in confined areas. The sealed Integral hydraulic pump design allows the tool to be used either above or below water.

HOW THE VLW18TI WORKS-

1.The tool is inserted into the access gap.

2.The pump is primed which powers the hydraulics that lift the load.

3.The pump is primed which powers the hydraulics that lift the load.

Example-

Problem-

A tensioner unit for an umbilical system on the deck of a vessel was required to be mobilised in 6 different configurations: 8” riser recovery, 10” riser recovery, 10” static installation, 6” static installation, 8” riser installation and 10” riser installation. Various packers were proposed in order to adjust the height of the tensioner unit in order for it to align tangentially with the fixed gooseneck, with each pipe diameter requiring slightly different packer thicknesses. A system capable of jacking the full frame and tensioner was preferred, as this could be lifted vertically (lifting only the tensioner would result in non-vertical lifting), however the tensioner and frame together were estimated to weigh around 75Te.

Solutions-

The Equalizer VLW18TE was selected as the ideal tool for the project. Four Maxi-kits were hired for the project, providing a total of 8 tools, or 144T of lifting capability. Each corner of the frame utilised a pair of tools, both running off a twin-port Equalizer hand pump, each with a gauge. In this configuration each pair of tools shared a pump so were automatically hydraulically equalised to ensure that one would not take more load than the  other. The gauges on each pump could be cross-referenced to ascertain the precise loading in each corner, and checked with the other corners to ensure the load was being lifted in a controlled and balanced manner. Custom stepped-blocks were designed and manufactured for the project, with the steps exactly sized to suit the individual stages required to install and remove the specific packers for each mobilisation. These exactly corresponded with the spacer packers placed between the beams, such that the travel of the tool was maximised and the time taken between configurations was minimised.

Operations-

Applications-

It is ideal for Construction, Shutdown, Petrochemical, Nuclear and Mining.

10 Quick interesting things about J Gun Duol Speed

The dual speed guns eliminate the need for impact guns used for pre-torquing. The splined reaction area allows for the user of custom reaction fixtures giving the user the flexibility to adapt the tool for any application.

The Torcgun is a precision air torque/tension compatible machine that unlike impact guns… you can set and get your desired load. Impact wrenches function by shocking the nut with fast blows by a hammer-like device. This leads to inaccuracies, heavy vibration and loud operating volume. The Torcgun uses precision gearing to produce constant, calibrated power assuring that you will achieve bolt load within your window of accuracy every time.

The 10 interesting things are as following-
1.Run in High Speed mode even with reaction arms and other accessories attached to the gun.

2.Bolt Load Accuracy Within ±5%.

3.Calibrated torque output unto 8000 dt-lbs.

4.Fixtures available for all challenging applications.

5.Very Low Noise With Silencer and Industry leading power to weight ratio.

6 Reduce Operator Error And Pinch Points. 
    
7. Built to withstand heavy use in all industries.

8.Versatility-
The ability to handle any job! The Torcgun is available in single and dual speed models. It is also compatible with our HYTORC Washer™ and The HYTORC Nut™ stretch-to-load fastening systems. A number of practical, user friendly accessories are available as well making the Torcgun most complete and versatile air gun available on the market today.

9.Lightweight, Durable & Powerful-
Don't be misled by the small size of the Torcgun! With the highest power-to-weight ratio of any comparable product… the Torcgun can handle any job thrown its way. Made from high-strength aluminum alloys, the Torcgun is lightweight but yet extremely resistant to damage. The gears and output shaft are composed of the highest quality materials ensuring superior performance and durability.

10.High Speed Rundown & Final Torque-
he Torcgun dual speed gun provides the speed and conveniences of an impact wrench without its noise, vibration and load variation. Its twin torque mechanism has a first stage for used for nut rundown and removal with amazing RPM's and torque! The second stage is used for applying the final torque (or stretch with the HYTORC Washer™ or The HYTORC Nut™) to the bolt.

Operations-

Application-
The JGun Duol speed is used in Oil And Gas, Petrochemical, 
Power Generation, Infrastructure,Ideal For Wheel Nuts Of 
Heavy Vehicles.
1.

2.

3.

10 Things About Hytorc Nut You Want To Know

For critical applications requiring the highest level of bolt load control, the patented HYTORC Nut system provides industry-leading joint integrity. This three-piece fastener applies pure tension to the bolt to prevent thread damage and ensure bolt load accuracy. 

The various applications are as following:-
1. Exhaust Diffuser Bolts

2.Coupling


3.Steam chest valves:-

4. Gas Turbines-

5.E Technology Casing Bolts

6.Frame 5 HJ and VJ

6. B Turbine VJ & H J

7.Turbine Shell Horizontal Flange

Features & Benefits:-

1.The HYTORC NUT™ is a perfect solution for limited radius applications.

2.Tools lock onto fasteners for hands-free operation 

3.Remote operation keeps personnel out of danger

4.Assures even and accurate bolt load for a perfect seal

 5.Creates pure tensile bolt loads with no stud torsion

6.Guaranteed to eliminate galling, allowing infinite stud reusability 

7.Cuts bolting time in half over alternative methods

8.Inline reaction improves safety by eliminating pinch points 

9.Works with a simple adapter for your HYTORC tools

10.The HYTORC NUT™ is available for any bolt size (imperial/metric), any thread configuration and upon request, is available in speciality materials to suite the application and environmental conditions.

ID Mount Flange Facing Tool

 Portable machining tools  have been the preferred choice by professional field machining specialists for construction and maintenance of power plants, refineries, pulp plants, and paper mills.

Its competitive advantage comes from engineering design know-how, applications experience, product quality and performance, customer relationships, and end-to-end solution capability.

H&S Tool offers four models of reliable pipe machine tools with premium flange facing conversion accessories. Each is powered by reliable pneumatic or electric motors to accurately meet your job site or shop requirements.

The tools are portable, making them ideal for use in the field.Setup and operation is easily handled by a single worker.Kits include everything necessary to convert your Model B, MS,MT or MFT beveling tool with illustrated instructions. Standard wedge plates can be used for internal locking or precision elbow mandrels are available. The mandrels are designed to mount in short-radius elbows. The minimum straight depth to mount the model MSF is .500" [12.7 mm], model MTF is 1.000" [25.4 mm] and model MFTF is 1.250" [31.8 mm]).Centering and squaring devices make accurate machining of gasket surfaces and/or bolt patterns simple and safe.

• Single Person Setup And Operation

• Field Conversion Between Beveling Machine And Flange Facer Is Quick And       Easy

• Adjust Between A Wide Range Of Face Surfaces

• Internal Locking Increases Safety and Accuracy

Models

Avanti Torque Wrench-why this is special

Avanti provides the highest level of bolting optimization with major advantages in safety, speed and accuracy.It provide torque from 156 Nm- 1,87,792 Nm.Its Reaction Arm Is  Mounted On The Square Drive Eliminating Torsional Force On The Cylinder. It Also Enables To Customize The Reaction And Suit The Application.

The 3-in-1 Hydraulic Bolting System

The First System

Capable of acheiving consistent calibrated load accuracy within 5% with torque accuracy of ±3%.

Inline Reaction

Reduces side load and increases tool durability.

Uniswivel Technology

For free movement and positioning of tool and hoses.

Four-in-One system

For pure-tension, torque, torque-angle and yield point bolting.

Advantage-
1.Capable of pure-tension, torque, torque-angle or yield point bolting
2. Hands-free operation with elimination of dangerous pinch points
3.Increased simplicity and function for job time reduction of up to 50%
4. Industry leading bolt-load accuracy within ± 5% when using the HYTORC Nut™
5. Uni-swivel technology and 360˚ reaction arm for free movement
6.Available in 10 sizes with torque output from 115 ft-lbs to over 138,000 ft-lbs.

Operation-

Applications-
It is used in Petrochemical, Offshore Subsea, Power Generation, Shipping industries.
1.Avanti with Custom Reaction Fixture

2.Avanti with Nut Driver on Inverted Application

3.Avanti Simultorc Bolting Application

4.Avanti Simultorc on Subsea Bolting Application

5. Avanti Simultorc On Dollar Plate Application