BOLT TENSIONERS This manual contains IMPORTANT WARNINGS, CAUTIONS and other instructions. Read and understand the instructions manual carefully before use and retain it for reference. TORCUP MIDDLE EAST FZE A4-80, SAIF Zone, P. O. Box 8911, Sharjah, UAE. Phone: +971.6.5573478 Fax: +971.6.5573479 Website: www.torcup.ae email: sales@torcup.ae
Introduction: In order to apply an evenly distributed load to a Bolted joint, the sequence in which Hydraulic Tensioners are applied to the joint is important. The exact detail of this sequence is dependant upon the number of Bolts in the joint and the number of Bolt Tensioners available. In order to optimize between cost of equipment and the time taken to tension the joint, it is generally agreed the correct Bolt/Tool ratio is 50%, in certain instances a 25% ratio is acceptable. The general rule is - the lower the Bolt/Tool ratio, the more time it will take to tension the joint. This operator procedure details a 50% Bolt/Tool ratio. For detailed information to Tensioning Sequences contact TorcUP. Precautions: Prior to connecting the hydraulic pump to any bolt tensioning equipment, the user is to ensure that - The working pressure of the hydraulic pump and the equipment to be operated are compatible. The reservoir pump capacity is adequate to operate the equipment throughout its range. The hydraulic oil specification used within the pump and the equipment are compatible. The technical specifications of the tensioning tools are known Ensure sufficient stud protrudes above the hexagon or round joint nut Parts of Bolt Tensioner : STUD/BOLT TENSIONING TOOL PART IDENTIFIER PULLER LOAD CELL BRIDGE NUT DRIVER Operational Sequence : Fig. 1 Fig. 2 Fig. 3 Fig. 4 Technical specification: The technical specification of your particular bolt tensioning tools can be found hard stamped on the Load Cell Body. 2
TORCUP BOLT TENSIONER OPERATING INSTRUCTIONS WARNING! All equipments used must be rated for the same operating pressure i.e., 1500 bar (21750 psi). DO NOT MIX high and low-pressure components. If in doubt, contact your local TorcUP Distributor. Safety Precautions: All general on-site safety procedures must be adopted when using this equipment. It is recommended that all operators using this system must be trained in the safe use of the equipment. Never attempt to use this High Pressure equipment if you are in any doubt regarding the correct assembly and operation. Always ensure the equipment used is in good working order. Always wear eye protection, gloves and safety boots. Non essential staff should vacate the immediate area during the tensioning sequence Always ensure that all personnel in the near vicinity are aware that pressurization of High Pressure equipment is about to take place. Only approach pressurised Bolt Tensioners when it is certain that the set pressure is holding steady on the pump pressure gauge. Never attempt to solve leaks in the system while it is under pressure. Shut the pump down immediately to zero pressure before attempting to resolve system leaks. Never exceed the maximum working pressure of the Bolt Tensioner. (See the tensioner specification hard stamped on the tool). Never exceed the maximum piston stroke of the Tool. Never stand in line with the bolts axis, unexpected bolt failure is highly dangerous. Ensure suitable thread engagement between tensioner and bolt is achieved ( 1 x the bolt diameter of thread should protrude from the joint hexagon nut on the side that the tensioners will be fitted) i.e for a M36 thread, 36mm of thread should protrude above the hexagon nuts. Examine hydraulic hose assemblies for crushed or badly kinked hoses, replace damaged hoses immediately. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN DAMAGE TO THE UNIT OR MAY RESULT IN OPERATOR INJURY OR DEATH. IF YOU ARE IN ANY DOUBT ABOUT ANY INSTRUCTION DETAILED IN THIS PROCEDURE, DO NOT HESITATE TO CONTACT TORCUP. 3
TENSIONING PROCEDURE Step 1 Ensure there is sufficient stud protruding from the top of the joint nuts. A minimum of ONE TIMES the STUD DIAMETER is essential. Example For a Bolt size of M36, the required stud protrusion is 36 mm. Also ensure full engagement through the hexagon nut on the opposite end of the studs being tensioned. D MINIMUM D Step 2 If Tommy bar holes are not drilled into hexagon nut faces assemble Nut Runners over every alternate Bolt to be simultaneously tensioned. Tighten down every bolt on the flange to be tensioned by using the Tommy bars supplied with the tensioning equipment. Ensure the two halves of the joint are pulled firmly together. Step 3 Assemble the bridge over the first 50% of bolts to be tensioned (every alternate bolt). Position the bridge window so that access to either the Nut Runner or hexagon nut is comfortably achieved. It is normal for the bridge window to face radially out from the centre of a circular flanged joint. Step 4 Examine around the circumference of the bridge base to ensure it is sitting flat against the tensioning surface. The bridge can be adjusted in relation to the load cell by means of two setscrews, around the base of the Load Cell. Step 5 Assemble the load cells over the first 50% of bolts to be tensioned (every alternate bolt). Position the hydraulic connections so that access is comfortably achieved. It is normal for the hydraulic connections to face radially out from the centre of a circular flanged joint. Step 6 Assemble the Stud Pullers into each Bolt Tensioner screwing onto the threads protruding above the hexagon nuts. Ensure the Stud Pullers are threaded to the same diameter, thread form and pitch as the bolts to be tensioned. Use the Tommy bars supplied with the tensioning equipment to fully screw down the Inserts, until contact is made with the top face of the Load Cells. 4
Step 7 Remove plastic protection caps from all male and female quick connect couplings. Connect a link hose from the Pump Unit to the first tool, connection is made by pulling back the spring loaded collar on the female connection, insert the male connector and release the female collar. A gentle tug on the link pipe should be enough to make sure the hose is connected properly. Step 8 Continue until all of the tensioners are connected together with link hoses. The last tensioner in the system will have an plugged port (In case male connector is fitted to port, remove connector & fit blanking plug supplied with tools). Connect load cell to either an Air Driven Pump unit or a Hand operated Pump Unit CAUTION : Never pressurize an unconnected male connector The tensioning system is now ready to apply a bolt load to the joint. Before applying pressure to the system make sure you understand the following points You are aware of the correct operation of the pump unit. You are aware of the maximum working pressure of the tensioners. (See Technical label specification on tensioners). You are aware of the maximum piston movement of the tensioner. You are aware of the required working pressure that must be applied to the tensioners. It is recommended the next procedures are read and understood prior to starting the tensioning. WARNING! During pressurisation procedure, continually monitor both piston stroke and pressure. Never exceed either. Piston stroke can be seen by an indicator line on the Piston emerging from the load cell. NEVER EXCEED MAXIMUM PISTON STROKE NEVER EXCEED MAXIMUM WORKING PRESSURE Step 9 Close Pressure Let Down Valve on pump unit, then pressurize the system to the required pressure. When the required pressure is reached, stop the pump (Hold Pressure). At this stage the bolts will be initially loaded with the load being held by the tensioners. 5
Step 10 Check the pump gauge to ensure the pressure is holding firm. When you are satisfied the pressure is stable, approach the tensioners and by using the Tommy bar, rotate the hexagon nuts, (through the Bridge access windows), back down towards the joint face. Seat the hexagon nuts firmly against the joint, by use of a mallet and Tommy bar (If the hexagon nuts are not seated firmly, the tensioning procedure will take much longer to complete). It is not important in which order the nuts are tightened but to be sure of not missing one, it is recommended they are tightened in sequence. Step 11 Slowly release the return to Tank valve on the pump. The load is now transferred from the tensioners to the nuts. Use a Tommy bar in the Threaded Stud Pullers to return the Piston to their fully closed position (Note If the desired pressure has not yet been reached, continue from Step 6). Step 12 Disconnect all of the hydraulic link hoses and reposition the tensioners onto the final 50% of Bolts to be tensioned, and repeat the tensioning operation on these un-tensioned bolts When de-tensioning, specific tool pressures are not normally available as it is not always possible to calculate the pressure at which the flange nut will break free. As a guide, if the original flange bolt tightening pressures are available, the de-tensioning pressure is usually marginally higher than the original tensioning pressure (but not always) SAFETY: Prior to commencement of bolt de-tensioning ensure that: All necessary safety precautions have been carried out Personnel involved in bolt tensioning are competent and fully trained in the use of bolt tensioners and tightening techniques. The procedure and data to be used is authorized by a responsible Engineer. The joints / pipe-work to be worked on are not 'live'. Joints must be at zero pressure and free from hazardous substances The maximum pressure that can be applied has been calculated to ensure that either 95% of bolt material yield is not exceeded or the maximum tool pressure is not exceeded, whichever is the lower. Pump must be pre-set to achieve this. DE-TENSIONING PROCEDURE Stage 1 Assemble the tensioning tools to the bolts. With the Stud Puller component fully screwed down and seated on the piston, unscrew the Stud Puller through one half turn. This will prevent the Thread insert becoming locked onto the piston when the bolt tension is released. Stage 2 Insert a tommy bar through the tensioner bridge window and into a hole in the nut rotating socket. Apply hydraulic pressure to the system until the flange nuts can be rotated, ensuring that the piston does not exceed maximum stroke or system pressure does not exceed that indicated in the safety notes above. Stage 3 Turn back each flange nut through one full turn (6 holes on the nut rotating socket). Stage 4 De-pressurize the system and check to see that the flange nuts are still free to rotate. Stage 5 Remove the bolt tensioners. If the Stud Puller cannot be unscrewed and the flange nut is also tight, then the Stud Puller has locked onto the top face of the flange nut see Stage 7. 6
Stage 6 If the Stud Puller cannot be unscrewed but the flange nut is free, then the Stud Puller has locked onto the piston - see STAGE 8. Stage 7 Stud Puller locked onto top face of nut - If the flange nut is unscrewed further than that indicated in STAGE 3, it can cause the nut to become locked onto the thread insert when bolt tension is released. To release the thread insert / flange nut, the hydraulic pressure must be re-applied and the flange nut rotated clockwise (to tighten) half a turn (3 holes on the nut rotating socket). Upon de-pressurization the Stud Puller should be free to rotate. Stage 8 Stud Puller locked onto piston - This occurs if the Stud Puller has not been unscrewed sufficiently in STAGE 1 (half a turn may be insufficient for fine threaded bolts) causing the thread insert to become locked onto the piston as the tension is released in the bolt. To release the thread insert, re-apply the hydraulic pressure and turn down the flange nut. Upon depressurization, the Stud Puller should freely rotate. Unscrew the thread insert a further half turn and repeat STAGES 2 to 5. SEAL REPLACEMENT PROCEDURE There are two seals used in TorcUP Hydraulic Bolt-Tensioners; one on the inner diameter of the Piston and another on the outer diameter of the Piston. Each seal comprises of an inner (Acrylonitrile Butadiene Rubber) and outer seal (Polytetrafluoroethylene with fillers). The replacement procedure is same for both types of seal. SEAL REMOVAL Isolate the failed load cell, unscrew and remove the hydraulic quick connect couplings. Remove the piston from the load cell body. It is recommended that both seals be replaced at the same time. Firmly hold the piston in a vice fitted with soft jaws. Using a smooth rounded screwdriver, firmly grip the sealing edge of the outer seal and pull it away from the seal housing. The same procedure can now be used on the inner seal. Discard the used seals. SEAL REPLACEMENT Thoroughly clean the seal housing and the hydraulic chamber of the load cell. Place the piston, bottom face up, on a clean flat surface. Offer inner rubber seal to the seal housing. Now place & push the seal into the housing by hand. Press seal as far as possible by hand & then by using any smooth round part on the top face of the seal. Ensure the seal is fully seated around its complete periphery. The same can now be applied to the inner seal. Before refitting the seal/piston assembly back into the load cell, smear the sealing edges with either hydraulic oil or light grease to ease piston assembly. Place the load cell body on flat clean surface with the hydraulic chamber facing upwards. Assemble the piston back into the load cell; making sure that the piston is not tilted during assembly. Finally refit the quick connect couplings. 7
WARRANTY CERTIFICATE This is to certify that TORCUP make Bolt-Tensioners supplied against the FINAL INSPECTION AND TEST REPORT Are inspected & found to be correct. TorcUP Bolt-Tensioners are warranted for 12 months from the date of despatch against defective workmanship & faulty material. This warranty is limited to replacement without charge, of parts found to be defective in material or workmanship and does not extend to claims for labour expense, or other loss or damage occasioned by such defect of material or workmanship. No unauthorized back charges will be accepted. This warranty does not cover deterioration by corrosion, erosion, or any cause of failure other than defect of material or Workmanship. This warranty however does not cover loss or damage in transit or any other factor beyond our control. TORCUP MIDDLE EAST FZE A4-80, SAIF Zone, P. O. Box 8911, Sharjah, UAE. Phone: +971.6.5573478 Fax: +971.6.5573479 Website: www.torcup.ae email: sales@torcup.ae 8