The research council on structural connections rcsc prepares specifications and documents related to structuralconnections rcscs specification for structural joints using astm a325 or a490 bolts 2000 is a widely used specification which discusses joints, fasteners, limit states, installation, and inspections structural bolting 3. The bolt bolt tightening procedure mechanical engineering general discussion engtips. This method is used to tighten bolts that have diameters greater than 20 mm, as these bolts need an extremely high tightening torque. Grip is the distance from behind the bolt head to the back of the nut or washer. This technical standard covers the procedures for tightening bolts on. There is no recognized quantitative relationship between torque and pretension in a bolt. Just make sure the dti bumps bear against the underside of the bolt head or against a hardened flat washer, never directly against the nut or the steel plates. Is there a simple equation or table to correlate installation tension and torque. Either way the calibration torque is determined on freshly tensioned assemblies which may or may not be what is to be inspected. Torque procedure this document defines general requirements for assembly of flanged joints in piping systems where controlled tightening of stud bolt using torque measurement is mandated. The torque sequence column shows which diagram to use as the specific bolt torquing sequence for your engine. All avco lycoming aircraft engines incorporate bolts and long thru studs that extend through the crankcase halves primarily for holding them together. How much torque is required to achieve 70% of the speci. This method employs a hydraulic ram placed over the nut and a threaded puller which attaches to the ram.
There are several ways of securing parts and components to. Bolting procedures hydraulic, torque, wrenches, pneumatic. Start the tightening procedure by lubricating the nuts and bolts. T the purpose of tightening screws is to fix one object to another object. Apply suitable axial tension it is best to do axial tension control for tightening screw, but actually it is difficult to measure. However with torque tightening the correct tensions can be realised for the ultimate connection for your flange. Breakout torque when loosening bolts a torque value higher than the tightening torque is normally required. Documentation of results the following is a sample bolting procedure using a manual or hydraulic torque wrench. Surface condition torque adjustment factors plain steel, as supplied x 1. Bolt tightening procedure mechanical engineering general. The problem arises when we attempt to generalize the procedure and assume that, since it took 850 foot pounds of torque to bring the 1 a325 bolt at the last job to correct pretension, that the same torque will work at the current job. Guideline for bolted flanged joint assembly in process plants. Cylinder head bolts main bearing bolts rod brearing bolts crankshaft damper bolts flywheel bolts manifold. This pretensioning or snug tightening can be accomplished by.
Just dont make the mistake, one step it says torque to 2 inch lbs. My understanding of whats going on in this bolt tightening procedure. Installation procedure connections with few tcbs 1. Flange joints require proper tightening to avoid the leak of the fluid from the joint. This procedure may be applied to all bolts requiring rotational capacity testing regardless of length. It is recommended to tighten all the bolts equally, and to avoid applying torque to one or several bolts on one side. Engineering fundamentals of threaded fastener design and analysis. Bolt tightening sequence or torque sequence is defined in torque tightening procedure.
Therefore, the target of bolt tightening reliability by the torque method is not to keep the axial tension fixed, but to maintain it within the given dispersion width. This procedure is described in the context of obtaining data for designing, constructing, or maintaining reclamation structures. Torque control and torqueangle control tightening methods. The bolts shall be then tightened torqued to the first torque level shown on the flange torquing table, using the crossbolting sequence marked on the.
This is again a minor aspect of the whole bolting operation, yet one which is often ignored. Always use a torque wrench or other controlledtensioning device for tightening. Shown is the bolt tightening sequences for typical circular flanges. Torque the three bolts previously installed inside camshaft gear cover to 5666 nm 4448 lbft. One of the central problems of using threaded fasteners for. Cylinderhead gasket and cylinderhead bolts all from one.
Therefore, the target of bolt tightening reliability by the torque method is not to keep the axial. Flanges and their joints gasket parameters and test procedures. Using the shear wrench but only snug tightening assemblies and. Mar 24, 2016 the torque required to return the fastener to its original location is the reference to the original torque applied to the fastener. As per fig 1 insert the bolt into the connection and place the washer, bevelled side outermost, onto the bolt followed by the nut. Repeat steps in procedure 9 increasing the torque to approximately 50% to 60 % of the final appropriate torque value. Procedures for rotational capacity testing of galvanized. Jul 25, 2010 this writeup details the procedure of torquing. In sophisticated tightening processes the angle can also be. We also sell perkins engine parts and subassemblies, order online. With over 25 years of experience our bolt tightening products are used throughout the. It is the sum of the thicknesses of all the parts being joined exclusive of washers.
Pocket guide to tightening technique this booklet provides an introduction to the technique of using threaded fasteners for assembling components, the application of power tools for the assembly and the influence of tool selection on the quality of the joint. An astm a325 or a490 bolt, an astm f1852 twistofftype. Do you verify that all bolt tension calibrators and torque wrenches. Flange bolt torque sequence and torque table a complete bolt. For more information on arp ultra torque visit our website at. Pdf bolt torque tightening procedures mohammed mujahed. Bolt length is the distance from behind the bolt head to the end of the bolt. Fastening errors can never be eliminated if proper torque.
They are performed by the bolt manufacturer and mdot metals lab prior to incorporation and are carried out in accordance with astm a325. Weve just checked a nut that we tightened and its well below what we tightened it to just minutes earlier whats wrong. Scribd is the worlds largest social reading and publishing site. A proper gasket installation, bolts with correct tension, and an evenly divided bolt strength must be adhered to to create a good flange connection. Outline materials divisionss quality assurance procedures for high strength bolts. All diagrams can be found in numerical sequence at the back of this publication.
Detroit diesel series 60 service manual pdf download. Jan 10, 2016 if an air wrench is used make sure the pressure is set to the minimum. Page 20 additional service information is available in the detroit diesel series 60 service manual, 6se483. They can be threaded onto a new or existing bolt, stud, threaded rod or shaft.
Arp ultra torque far surpasses all requirements offered by previous arp lubricants in terms of fastener preload repeatability and performance lubricating properties. Some equipment requires special bolt tightening procedures. The tightening method and the tightening torque or bolt preload must be. Due to short length of existing bolt, torque wrench or hammer wrench will be used for bolting unbolting. It is important not only to improve the reliability of the bolt tightening work. There can be as many as 200 or more factors that affect the tension created in a bolt when tightening torque is applied refer to paragraph 2. Bolts up to 1020 ftlbs torque, but do not exceed 20% of target torque. If an air wrench is used make sure the pressure is set to the minimum. For example, you may have to use a torque wrench to correctly tighten the bolts to the specification, or tighten the bolts in a special order. Do not use these values if a different torque value or tightening procedure is given for specific application.
Engineering fundamentals of threaded fastener design and analysis by ralph s. Consequently always torque nuts in a cross bolt tightening pattern. Only applicable to shaft screws with metric standard and fine threads acc. F is greater than the maximum torque tmax the bolt assembly fails the rotational capacity test. The bolts or the flange shall be numbered with the crossbolting pattern sequence to be used. The objective of this test is to verify that a rock bolt or an anchor has a certain specified. If two washers are being used, ensure the washer under the bolt head is placed. This is due to its simplicity and its widespread understanding by all engineers. Theoretical relationships developed for an installation torque versus installed pretension can be signi. As per fig 1 insert the bolt into the connection and place the washer.
The stretch of a bolt or metal rod loaded in tension is calculated by use of the following equation. The 5 step guide to torque tightening for leakfree flange. Bolt tightening 2 bolt tightening 21 various tightening methods various tightening methods 34 22 screw and torque relation formula between screw and torque 35 23 torque coefficient 1 formula of torque coefficient 36 2 the torque coefficient is not stable 36 3 even when the torque is stable, axial tension may vary 36. Procedures for rotational capacity testing of galvanized astm. Please note it is not the same as tensioning, which requires an altogether different approach. The sequence in which bolts or studs are tightened has a substantial bearing. Specification for structural joints using astm a325 or. Torque curve for 45,000 psi bolt stress torque required. The threaded section of the bolt should extend past the nut for this method to succeed. Shear bolts are designed to fail under predetermined loads.
Flange bolt torque sequence and torque table a complete. Torque tensioners shall be calibrated and used within the dates of validity for. Superbolt tensioners are designed as direct replacements for standard bolting. With our products, bolting is fast, safe, easy and accurate. Nut markings should be outermost to ensure quality assurance is visible. At fourth stage again use 70 percentage of the final torque value. Lubricated refers to fasteners in the as received condition, which is normally a light preservative oil coating on unplated fasteners and no oil coating on plated fasteners. The bolt is stressed up to the proofload value, and if there is no deformation, elongation, or fracture, then the bolt is deemed to have passed. Flange bolt torque sequence and torque table a complete bolt tightening procedure flange joints require proper tightening to avoid the leak of the fluid from the joint. Correct tightening of a bolt means making the best use of the bolts elastic properties. The guide to design criteria for bolted and riveted joints,2nd edition kulak et al. If the turntotension procedure is used to establish clamping load, it is necessary to know both the spring rate of the bolt and the spring rate of the clamped components, since turning the bolt stretches the. Failure of the rotational capacity test does not necessarily mean that the bolts, nuts, and washers.
The first time around tighten to approximately 12 of the final torque, and then repeat the sequence, tightening to the suggested torque limit. A new approach to the tightness checking of bolts bill eccles, bolt science a frequent question that is asked relating to bolting is. Then hand tighten till they are snug against the flanges. A separate procedure is provided for long and short bolts. For bolting specifications that do not have a published proofload, it is usually calculated at 92% of minimum yield strength. Fortunately, torque angle signature curves can be obtained for. Torque is the force used to tighten fasteners or the amount of rotational force that a fastener must be able to withstand before failure. Bolt tightening solutions no matter what your preference for bolt tightening, atlas copco have it covered. Do not fully tighten the bolts the first time around as this can tilt the flange out of parallel. Torque control and torque angle control tightening methods using torque to indirectly control a bolts preload is by far the most popular controlled tightening method.
Bolt tightening table table 14 table 15 figure 21 1. This assembly torque is designed to achieve a preloading in the bolt expressed in. Visually examine and clean flanges, bolts, nuts and washers. Increase the torque to full torque following the pattern shown above. How to conduct the marking torque test method youtube. While tightening the bolt with torque wrenches for pipe manway flanges ensure that tightening load to each bolt is applied as uniformly as possible. One final time clockwise or counter clockwise sequentially around the flange. Engineering fundamentals of threaded fastener design and. Bolt tightening sequence or torque sequence is key to achieve this. A procedure for bolting should include specific instructions for. The american society of mechanical engineers or asme provides standards for how much torque fasteners should withstand and proper torquing during assembly. This assembly torque is designed to achieve a preloading in the bolt expressed in percentage of the bolt yield stress. Determining rock bolt or anchor tension using a torque wrench.
Always replace shear bolts with identical property class. First round 30% of final torque flange sequential order second round 60% of final torque flange sequential order third round 100% of final torque flange sequential. The total thickness of the plies of a joint through which the bolt passes, exclusive of washers or directtension indicators. Keystone rv recommends this maintenance procedure to ensure proper torque has been applied to lug nuts before heading out on the road. Figure 2 shows the main parts of the bolt assembly. Perform one final pass on each bolt working clockwise from bolt 1, at the full final torque. Continue torquing all studs in the sequence of figure 1, using the specified appropriate torque setting 100%, until there is no further rotation of nuts. When tightening, always use the correct sequential bolt order for the flange. Year engine displacement liters engine idvin cylinder head bolts. Attachment is from a procedure regarding conrod bolts, torque to yield type. Tightening procedures for crankcase thrustuds and bolts all avco lycoming piston engines.
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