[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”3_5,2_5″ _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”3_5″ _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n
How do the hydraulic forces generated at the wear rings make your pump more reliable?<\/h2>\n
Next time you are working on a pump in your repair shop, consider the role of the wear rings and\u00a0<\/span>throttle bushings<\/a>. They create stabilizing forces in the pump due to the Lomakin Effect. When you reduce your wear ring clearance using DuPont\u2122\u00a0<\/span>Vespel\u00ae CR-6100<\/a>\u00a0or\u00a0<\/span>Boulden B-Series Composite materials<\/a>, you can maximize these forces and make your pump more reliable.<\/p>\n The Lomakin Effekt is a force created at the\u00a0wear rings<\/a>\u00a0and\u00a0throttle bushings<\/a>\u00a0within a centrifugal pump. The force is a result of unequal pressure distribution around the circumference of the component during periods of rotor eccentricity or shaft deflection. [\/et_pb_text][\/et_pb_column][et_pb_column type=”2_5″ _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/bouldencompany.com\/wp-content\/uploads\/2021\/12\/lomakin-effect.jpg” alt=”The Lomakin Effect” title_text=”lomakin-effect” _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.17.3″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n In other words, when your pump experiences shaft deflection, there is a hydraulic \u201cstiffness\u201d (Lomakin Stiffness) which is generated to counteract the shaft deflection. The Lomakin stiffness coefficient (kLomakin)\u00a0for a wear ring or\u00a0throttle bushing<\/a>\u00a0is represented by the following equation:<\/p>\n kLomakin<\/em>\u00a0= (RL\u2206P\/c)K\u00a0(N\/mm) Dupont\u2122 Vespel\u00ae Machined Parts<\/a> B-835<\/a> Boulden has a\u00a0large inventory of standard sizes<\/a>\u00a0of Vespel\u00ae CR-6100 in the U.S., Europe, and Singapore to help you make the upgrade today.\u00a0 Vespel\u00ae CR-6100 or one of our\u00a0B-Series composite materials<\/a>\u00a0can be used in almost all chemicals and temperatures from cryogenic to 500F (260C). Sign up for our\u00a0newsletter<\/a>\u00a0or visit our\u00a0blog<\/a>\u00a0to stay up to date about our materials and components.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":" THE LOMAKIN EFFECTHow do the hydraulic forces generated at the wear rings make your pump more reliable? Next time you are working on a pump in your repair shop, consider the role of the wear rings and\u00a0throttle bushings. They create stabilizing forces in the pump due to the Lomakin Effect. When you reduce your wear ring clearance using DuPont\u2122\u00a0Vespel\u00ae CR-6100\u00a0or\u00a0Boulden B-Series Composite materials, you can maximize these forces and make your pump more reliable. What is the Lomakin Effect? The Lomakin Effekt is a force created at the\u00a0wear rings\u00a0and\u00a0throttle bushings\u00a0within a centrifugal pump. The force is a result of unequal pressure distribution around the circumference of the component during periods of rotor eccentricity or shaft deflection.Figure 1\u00a0shows how shaft deflection creates the unequal pressure distribution. As the fluid enters the clearance between the rotor and wear component, it accelerates as it passes from the high pressure end to the low pressure end. Due to the eccentricity of the rotor, there is more clearance on one side of the wear ring than the other. There will be more flow and a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"custom-template.php","meta":{"_acf_changed":false,"_et_pb_use_builder":"on","_et_pb_old_content":"What is the Lomakin Effect?<\/h2>\n
Figure 1<\/strong>\u00a0<\/span>shows how shaft deflection creates the unequal pressure distribution. As the fluid enters the clearance between the rotor and wear component, it accelerates as it passes from the high pressure end to the low pressure end. Due to the eccentricity of the rotor, there is more clearance on one side of the wear ring than the other. There will be more flow and a locally higher velocity on the side with more clearance and lower velocity on the side with less clearance. Higher velocity results in lower pressure; lower velocity results in higher pressure, creating a net corrective force which acts in the direction opposite of the shaft deflection.<\/p>\n
R = Wear Ring Radius (mm)
L = Wear Ring Length (mm)
\u2206P = Differential Pressure(MPa)
c = Radial Clearance (mm)
K = non-dimensional stiffness coefficient
The lone variable you can easily manipulate in this equation is the clearance. If you reduce the\u00a0wear ring clearance<\/a>\u00a0by 50%, you double the Lomakin stiffness.
Which pumps benefit the most? Any pump where the shaft is long and thin. Typical examples are older overhung pumps with high\u00a0L3\/D4 ratios\u00a0and multi-stage horizontal pumps like\u00a0boiler feed water pumps\u00a0and product shipping pumps. Also, any pump where clearance was increased in the past to avoid\u00a0pump seizure<\/a>. When you upgrade to\u00a0Vespel\u00ae CR-6100 or one of the\u00a0B-Series composites<\/a>, you minimize the risk of pump seizure and can confidently run tighter clearances, which also\u00a0improves the pump efficiency<\/a>.<\/p>\nAdditional DuPont\u2122 Vespel\u00ae CR-6100 Resources<\/h2>\n
Vespel\u00ae CR-6100 Applications<\/a>
Problems Vespel\u00ae CR-6100 Solves \/Case Studies<\/a>
Industries Vespel\u00ae CR-6100 Serves<\/a>
Vespel\u00ae CR-6100 Resources<\/a><\/p>\nAdditional B-Series Resources<\/h3>\n
B-920<\/a>
B-1050<\/a><\/p>\nLearn more about Our Composite Materials and Components<\/h2>\n
\n \t
The Lomakin Effect<\/h1>\n\n
How do the hydraulic forces generated at the wear rings make your pump more reliable?<\/h2>\nNext time you are working on a pump in your repair shop, consider the role of the wear rings and throttle bushings<\/a>. They create stabilizing forces in the pump due to the Lomakin Effect. When you reduce your wear ring clearance using DuPont\u2122 Vespel\u00ae CR-6100<\/a> or Boulden B-Series Composite materials<\/a>, you can maximize these forces and make your pump more reliable.\n
What is the Lomakin Effect?<\/h2>\nThe Lomakin Effekt is a force created at the wear rings<\/a> and throttle bushings<\/a> within a centrifugal pump. The force is a result of unequal pressure distribution around the circumference of the component during periods of rotor eccentricity or shaft deflection.\nFigure 1<\/strong> shows how shaft deflection creates the unequal pressure distribution. As the fluid enters the clearance between the rotor and wear component, it accelerates as it passes from the high pressure end to the low pressure end. Due to the eccentricity of the rotor, there is more clearance on one side of the wear ring than the other. There will be more flow and a locally higher velocity on the side with more clearance and lower velocity on the side with less clearance. Higher velocity results in lower pressure; lower velocity results in higher pressure, creating a net corrective force which acts in the direction opposite of the shaft deflection.\nClick Here for the Vespel\u00ae CR-6100 INSTALL GUIDE<\/a><\/strong>\n
![\"Lomakin](\"https:\/\/bouldencompany.com\/wp-content\/uploads\/2021\/12\/lomakin-effect.jpg\" "\\"Lomakin")
\n\nIn other words, when your pump experiences shaft deflection, there is a hydraulic \"stiffness\" (Lomakin Stiffness) which is generated to counteract the shaft deflection. The Lomakin stiffness coefficient (kLomakin) for a wear ring or throttle bushing<\/a> is represented by the following equation:\n\nkLomakin<\/em> = (RL\u2206P\/c)K (N\/mm)\nR = Wear Ring Radius (mm)\nL = Wear Ring Length (mm)\n\u2206P = Differential Pressure(MPa)\nc = Radial Clearance (mm)\nK = non-dimensional stiffness coefficient\nThe lone variable you can easily manipulate in this equation is the clearance. If you reduce the wear ring clearance<\/a> by 50%, you double the Lomakin stiffness.\nWhich pumps benefit the most? Any pump where the shaft is long and thin. Typical examples are older overhung pumps with high L3\/D4 ratios and multi-stage horizontal pumps like boiler feed water pumps and product shipping pumps. Also, any pump where clearance was increased in the past to avoid pump seizure<\/a>. When you upgrade to Vespel\u00ae CR-6100 or one of the B-Series composites<\/a>, you minimize the risk of pump seizure and can confidently run tighter clearances, which also improves the pump efficiency<\/a>.\nAdditional DuPont\u2122 Vespel\u00ae CR-6100 Resources<\/h3>\nDupont\u2122 Vespel\u00ae Machined Parts<\/a>\nVespel\u00ae CR-6100 Applications<\/a>\nProblems Vespel\u00ae CR-6100 Solves \/Case Studies<\/a>\nIndustries Vespel\u00ae CR-6100 Serves<\/a>\nVespel\u00ae CR-6100 Resources<\/a>\n
Additional B-Series Resources<\/h3>\nB-835<\/a>\nB-920<\/a>\nB-1050<\/a>\n
Learn more about Our Composite Materials and Components<\/h3>\nBoulden has a large inventory of standard sizes<\/a> of Vespel\u00ae CR-6100 in the U.S., Europe, and Singapore to help you make the upgrade today. Vespel\u00ae CR-6100 or one of our B-Series composite materials<\/a> can be used in almost all chemicals and temperatures from cryogenic to 500F (260C). Sign up for our newsletter<\/a> or visit our blog<\/a> to stay up to date about our materials and components.","_et_gb_content_width":"","om_disable_all_campaigns":false,"_analytify_skip_tracking":false,"footnotes":""},"acf":{"content_type":["Success Stories"],"associated_material":["Vespel CR-6100","B-835"],"industry_application":["Refinery","Petrochemical","Midstream Oil & Gas","Fertilizer"],"component":["Pump Wear Rings"]},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/pages\/1034"}],"collection":[{"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/comments?post=1034"}],"version-history":[{"count":18,"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/pages\/1034\/revisions"}],"predecessor-version":[{"id":5370,"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/pages\/1034\/revisions\/5370"}],"wp:attachment":[{"href":"https:\/\/bouldencompany.com\/wp-json\/wp\/v2\/media?parent=1034"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}