Hp horsepower is the actual or transmitted power required by the application if unknown, use the motor or turbine. S trade association for the oil and natural gas industry, representing about 400 corporations involved in production, refinement, distribution, and many other. Explanation about the pump configurations within the api 610. Rough align the machine horizontally using a scale. Piping stress considerations and practical remedies to overcome. The 10 steps outlined in this article reflect modifications. Api 686 practices shaft alignment free download as pdf file. Nema sm23, steam turbines for mechanical drive service, national electrical manufacturers association, washington, d. Api recommended practice 686 machinery installation and installation designlast update. In its first 100 years, api has developed more than 700 standards to enhance operational safety, environmental protection. Our handson laser alignment course runs for two or three days. Recommended practice for machinery installation and installation design march 2012 supplement to pip reie686 api rp686 process industry practices page 2 of 29 introduction purpose this practice supplements pip reie686 api rp686, recommended practice for machinery installation and installation design. Besides his work, alan enjoys spending time with his family and numismatics. Main engine shaft alignment comprehension check conditions.
Main engine shaft alignment comprehension check conditions items tolerance docking undocking bearing loads or reactions jackup curve understanding this content is password protected. A good static alignment is required for troublefree dynamic operation of the propulsion shafting. Changes in the temperature of machines from off line to running can have a significant impact on the shaft alignment. The course covers from the fundamentals in laser alignment techniques, to performing a proper dynamic movement study thermal growth. Rotate the shaft until the dial gauge reaches a maximum or a minimum reading. Alignment check methodology for rotary equipment using caesar. Shaft misalignment is responsible for as much as 50 percent of all costs related to rotating machinery breakdowns. Api standard 617, centrifugal pumps for general refinery services, american petroleum institute, washington, d. It is a major cause of repeatability problems in shaft alignment measurements.
I would like to have clarification with regards to shaft alignment tolerances mentioned in api 686 second edition dec 2009 clause 5. Recommended practice for machinery installation and installation design march 2012 supplement to pip reie686 api rp686 process industry practices page 2 of 29 introduction purpose this practice supplements pip reie686 api rp686, recommended practice. Once the step shimming task is complete and the alignment of the machines has been rechecked with all anchor bolts tight, do not neglect to trim off the excess part of the shims protruding out from under the edge of the machines foot to prevent possible injury. In addition to alignment quality and repeatability problems, it can be a cause of machinery vibration, reduce life in electric motors, and cause internal clearance problems in gearboxes and pumps. Care has been taken by the authors, pruftechnik ltd, in the preparation of this publication. Mauricio, the american petroleum institute api has shaft alignment standards api 610 that are used in the petrochemical industry, and i believe the hydraulic institute has developed shaft alignment standards as well. Compressors, fans, blowers api std edition year published. There are two types of misalignment, offset and angular see figure 2. Our handson laser alignment, vibration analysis and dynamic balancing of rotor courses run for two or three days. Api rp 686 recommended practice for machinery installation. Pipe strain, and its effect on shaft alignment empowering. Recommended practice for machinery installation and installation. Api 686 best practice for installation empowering pumps.
Shaft misalignment occurs when the center lines of coupled shafts do not. Process measurement instrumentdescripcion completa. Api standard 617, centrifugal pumps for general refinery services, american petroleum institute. If a manufacturer of a machine or coupling requires tighter alignment tolerances, those should be used. Acquip laser alignment training courses and seminars. The aligning of two adjacent machinery shafts after the measurement of. To take an example, a machine running at 6000 rpm with a 300mm spacer shaft installed would allow a maximum offset of. Shaft alignment laser measuring resolution down to 0. We provide shaft alignment api 686 compliance certification for your plant maintenance staff.
Shaft alignment chapter 8 lubrication systems chapter 9 commissioning. With a loadonpad design, figure 1 the shaft is free to laterally within bearing clearance, and alignment data is difficult to obtain without temporary bearing shims to stabilize the sham with a loadbetweenpad design, figure 1 b, the shaft remains stable during the alignment procedure. Only disc couplings and diaphragm couplings can be used in api 671 applications. Api was formed in 1919 as a standardssetting organization and is the global leader in convening subject matter experts across segments to establish, maintain, and distribute consensus standards for the oil and gas industry.
For spacer shafts, the table gives the maximum allowable offset for each 100 mm or inch of spacer shaft length. The main purpose of shaft alignment is to make sure that the center line of the motor rotor shaft coincides with the center line of the driven machinery i. Rough align rough align the machine vertically using a scale. Standards referenced by this book show below hide below api 618. Applying one of the balancing quality grades such as iso 1940 and api 617. Api 686 only gives a recommended angular tolerance and nothing for offset alignment. Process industry practices recommended practice for machinery installation and installation design api recommended practice 686 second edition, december 2009. Api 686 chapter 4, piping alignment notes that the basic method of verifying pipe strain and its effect on the machinery is to monitor shaft alignment with dial indicators or lasers thru the machine flange torquing procedure. Aim to have all soft foot readings within 2 mils thou.
Alignment check methodology for rotary equipment using. Experimental method which can be used for mass production. Api 671 couplings are typically specified in critical applications that operate for extended periods of time, are often nonspared, have high torque andor speed requirements. Astm, iso, apipick an acronym, they all have specifications on. Machinery alignment tolerance tables the suggested alignment tolerances shown here are general values based upon experience and general industry standards and should not be exceeded. Moreover, as the name suggests, the main purpose of shaft alignment is to make sure that the center line of the motor rotor shaft coincides with the center line of the driven machinery i.
Oct 15, 2014 gear and quill shaft type couplings are permitted in the api 671 standard but are not common. The goal and purpose of the pre alignment steps is to control unintended movement that might occur during the alignment process and maximize repeatability. These changes in the shaft alignment can be accommodated in a few different ways. A static condition observed at the bearings supporting the propulsion shafts. Soft foot is a common issue when aligning rotating equipment. Api recommended practice 686 process industry practices. A catalog of api publications and materials is published annually and updated quarterly by api, 1220 l street, n. Table of contents a what is alignment b what is misalignment c types of misalignment d method of alignment e symptoms of misalignment f pre alignment checks g tools required for alignment h alignment tolerances. It is calculated, conducted and verified when the system is at rest. When shafts are aligned, the offset and the angular must be aligned. Shaft centerline alignment is the positioning of the rotational centers of two or more shafts such that they are colinear when the machines operate under normal conditions. Save api rp 686 recommended practice for machinery installation for later. The purpose of this article is to give you a explanation about the pump configurations within the api 610.
As per the code if the vertical and horizontal deviation of piping flange and rotary equipment flange centerline is within 1. Hello members i would like to have clarification with regards to shaft alignment tolerances mentioned in api 686 second edition dec 2009. The courses covers from the fundamentals in laser alignment techniques, to performing a proper dynamic movement study thermal growth. Theprocess of reducing the misalignment of two adjacent shafts connected by a coupling so that the center of rotation for each shaft as near is. American petroleum institute code api rp 686 provides the data for acceptable deviation from the ideal perfect alignment. I am not the absolute know everything about everything when it comes to the installation of process equipment. This recommended practice rp is intended to provide recommended procedures, practices, and checklists for the installation and precommissioning of new, existing, and reapplied machinery and to assist with the installation design of such machinery for petroleum, chemical, and gas industry services facilities. Api 686 shaft alignment tolerances api american petroleum. The initial version of this procedure was published several years ago by me. Metallic flexibleelement couplings are the primary type permitted for api 671 applications. Soft footwhat it is and how to minimize it vibralign.
With feeler gauge find obvious gaps and fill them with shims, taking care of any rough soft foot condition. Pdf process industry practices recommended practice for. Take a normal set of shaft alignment measurements with the piping connected. Api standard 610, centrifugal pumps for general refinery services. Recommendations for checking rotating machinery installation. Chapter 6 provides guidelines for piping alignment as. It can be resolved into a parallel offset at a given point along the fixed machine centerline and angular misalignment in both the horizontal and vertical planes. In the past i have represented the end users or have done the construction myself. Api standards are available for purchase at the api publications store at. Physical space limitations special bore or finish information and type of fit. Fixturlaser alignment tools display angular misalignment as a slope rise over run in mils1 the 0. A similar process can also easily be done with laser shaft alignment tools.
Alignment of the shaft is necessary when the motor or driven machinery is new or when it is dismantled due to improper running. Laser alignment is an essential component of a viable. Recommended practice for machinery installation and. The api is an abbreviation for american petroleum institute. However, i do want to share some knowledge and create conversation about this topic. The laser method will not tell you how much the flanges have moved, but will tell you if that movement is sufficient to cause a change of shaft alignment between the machines. I cant see anything in api 610 or api 617 for pump or. Api standard 610, centrifugal pumps for general refinery services, american petroleum institute, washington, d. How to do the alignment of shafts, compressors and. Shaft alignment methods explained bright hub engineering.
Hello members i would like to have clarification with regards to shaft alignment tolerances mentioned in api 686 second edition dec 2009 clause 5. It is not intended as a comprehensive guide to alignment of process machinery, nor is it a substitute for seeking professional advice or. Api 686 is written such that it can be used as a contractual document. Chapter 7 shaft alignment chapter 8 lubrication systems. It is not intended as a comprehensive guide to alignment of process machinery, nor is it a substitute for seeking professional advice or reference to the manufacturers of the machinery. Shaft centerline alignment is the positioning of the rotational centers of two.
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