{"id":9324,"date":"2026-08-04T22:18:58","date_gmt":"2026-08-04T13:18:58","guid":{"rendered":"https:\/\/now0930.pe.kr\/wordpress\/?p=9324"},"modified":"2026-08-04T22:19:00","modified_gmt":"2026-08-04T13:19:00","slug":"mainternance-control-valve-handbook-8%ec%9e%a5","status":"publish","type":"post","link":"https:\/\/now0930.pe.kr\/wordpress\/mainternance-control-valve-handbook-8%ec%9e%a5\/","title":{"rendered":"Mainternance Control Valve Handbook, 8\uc7a5"},"content":{"rendered":"\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/08\/valve-1-1.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"valve-1\uc758 \uc0bd\uc785.\"><\/object><a id=\"wp-block-file--media-18d6fd6f-90f9-4c41-9587-de2172cd8438\" href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/08\/valve-1-1.pdf\">valve-1<\/a><a href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/08\/valve-1-1.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-18d6fd6f-90f9-4c41-9587-de2172cd8438\">\ub2e4\uc6b4\ub85c\ub4dc<\/a><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code>{\n  \"topic_id\": \"control_valve_chapter8_installation_diagnostics_bench_set_travel\",\n  \"title\": \"Control Valve Handbook Chapter 8 \ud575\uc2ec \uc124\uce58 \ubc0f \uc720\uc9c0\ubcf4\uc218\",\n  \"language\": \"ko\",\n  \"purpose\": &#91;\n    \"\uc0b0\uc5c5\uacc4\uce21\uc81c\uc5b4\uae30\uc220\uc0ac \ub2f5\uc548 \uc791\uc131\",\n    \"\uc81c\uc5b4\ubc38\ube0c \uc124\uce58 \ubc0f \uc2dc\uc6b4\uc804\",\n    \"\uc2a4\ub9c8\ud2b8 \ubc38\ube0c \uc9c4\ub2e8\",\n    \"\uc561\ucd94\uc5d0\uc774\ud130 Bench Set \ubc0f Travel \uac80\uc99d\",\n    \"\uc608\uce21\uc815\ube44\uc640 \uc815\ube44 \ud6c4 Validation\"\n  ],\n  \"source_scope\": {\n    \"primary_source\": \"Emerson Control Valve Handbook, Sixth Edition\",\n    \"chapter\": 8,\n    \"included_sections\": &#91;\n      \"8.2 Proper Installation Techniques\",\n      \"8.3 Control Valve Maintenance\",\n      \"8.3.4 Using Control Valve Diagnostics\",\n      \"8.5.5 Bench Set\",\n      \"8.5.6 Valve Travel\"\n    ],\n    \"minimally_included\": &#91;\n      \"8.5.1 Spring-and-Diaphragm Actuators\",\n      \"8.5.2 Piston Actuators\",\n      \"8.5.3 Stem Packing\",\n      \"8.6 Shutdown Turnaround Outage planning concept\"\n    ],\n    \"excluded_or_reduced\": &#91;\n      \"8.1 detailed storage procedures\",\n      \"8.4 detailed OEM parts and parts-kit discussion\",\n      \"8.5 detailed disassembly and seat-ring replacement procedures\",\n      \"8.6 vendor-specific long-term STO planning stages\"\n    ]\n  },\n  \"core_logic\": {\n    \"statement\": \"\uc81c\uc5b4\ubc38\ube0c\uc758 \uc2e0\ub8b0\uc131\uc740 \uc62c\ubc14\ub978 \uc124\uce58, \uc6b4\uc804 \uc911 \uc0c1\ud0dc\uc9c4\ub2e8, \uc0c1\ud0dc\uae30\ubc18 \uc815\ube44 \ubc0f \uc815\ube44 \ud6c4 \uc131\ub2a5\uac80\uc99d\uc758 \ud3d0\ub8e8\ud504\ub85c \ud655\ubcf4\ud55c\ub2e4.\",\n    \"sequence\": &#91;\n      \"proper installation\",\n      \"commissioning\",\n      \"in-service monitoring\",\n      \"fault detection\",\n      \"fault discrimination\",\n      \"process recovery\",\n      \"validation\",\n      \"return to monitoring\"\n    ]\n  },\n  \"installation\": {\n    \"objectives\": &#91;\n      \"\ubc30\uad00 \uc774\ubb3c\uc9c8\uc5d0 \uc758\ud55c \uc2dc\ud2b8 \ubc0f \ud2b8\ub9bc \uc190\uc0c1 \ubc29\uc9c0\",\n      \"\uc720\ub3d9\ubc29\ud5a5 \uc624\ub958 \ubc29\uc9c0\",\n      \"\ubc30\uad00\uc751\ub825\uacfc \uc815\ub82c\ubd88\ub7c9 \ubc29\uc9c0\",\n      \"\ucda9\ubd84\ud55c \uacc4\uc7a5\uacf5\uae30 \uacf5\uae09\",\n      \"\uc815\uc0c1 Travel \ubc0f Fail-Safe \ud655\uc778\"\n    ],\n    \"required_checks\": &#91;\n      \"manufacturer instruction manual\",\n      \"nameplate and design specification\",\n      \"pipeline cleanliness\",\n      \"flow direction\",\n      \"flange alignment\",\n      \"actuator support\",\n      \"instrument air supply\",\n      \"zero and span\",\n      \"rated travel\",\n      \"seat and packing leakage\",\n      \"fail action\"\n    ],\n    \"force_margin_equation\": \"F_margin = F_actuator_available - F_valve_required\",\n    \"required_force_equation\": \"F_valve_required = F_process + F_packing + F_mechanical + F_additional\",\n    \"failure_relation\": \"F_mechanical increases -> F_margin decreases -> travel deviation, stick-slip, insufficient seat load or fail-safe failure\"\n  },\n  \"maintenance_strategies\": {\n    \"reactive\": {\n      \"trigger\": \"after failure\",\n      \"advantage\": \"low initial maintenance cost\",\n      \"disadvantages\": &#91;\n        \"unexpected shutdown\",\n        \"emergency repair\",\n        \"possible misdiagnosis\"\n      ]\n    },\n    \"preventive\": {\n      \"trigger\": \"fixed time or overhaul interval\",\n      \"advantage\": \"repair before some failures occur\",\n      \"disadvantages\": &#91;\n        \"unnecessary disassembly\",\n        \"over-maintenance\",\n        \"degraded valves may remain until scheduled overhaul\"\n      ]\n    },\n    \"predictive\": {\n      \"trigger\": \"condition and degradation trend\",\n      \"advantage\": \"maintenance is applied to the required valve at the required time\",\n      \"recommended_for\": \"critical control valves\"\n    }\n  },\n  \"maintenance_loop\": {\n    \"steps\": &#91;\n      {\n        \"name\": \"Fault Detection\",\n        \"purpose\": \"\uc6b4\uc804 \uc911 \uace0\uc7a5 \ubc1c\uc0dd \uc5ec\ubd80 \ud0d0\uc9c0\"\n      },\n      {\n        \"name\": \"Fault Discrimination\",\n        \"purpose\": \"\ub9c8\ucc30, \ub204\uc124, \uacf5\uae09\uc555\ub825, \ud3ec\uc9c0\uc154\ub108 \ubc0f \ud2b8\ub9bc \ubb38\uc81c \uad6c\ubd84\"\n      },\n      {\n        \"name\": \"Process Recovery\",\n        \"purpose\": \"\uace0\uc7a5 \uc6d0\uc778 \uc870\uc815, \uc138\uc815, \uc218\ub9ac \ub610\ub294 \uad50\uccb4\"\n      },\n      {\n        \"name\": \"Validation\",\n        \"purpose\": \"\ucd08\uae30 \ub610\ub294 \uc9c1\uc804 \uae30\uc900 \uc0c1\ud0dc\uc640 \ube44\uad50\ud558\uc5ec \uc131\ub2a5\ubcf5\uc6d0 \ud655\uc778\"\n      }\n    ]\n  },\n  \"diagnostics\": {\n    \"instrument_air_leakage\": {\n      \"measured_variable\": \"instrument air mass flow\",\n      \"possible_faults\": &#91;\n        \"tubing leakage\",\n        \"fitting leakage\",\n        \"diaphragm damage\",\n        \"piston seal leakage\",\n        \"o-ring damage\"\n      ],\n      \"trend_rule\": \"current air mass flow greater than baseline indicates possible leakage\"\n    },\n    \"supply_pressure\": {\n      \"equation\": \"deltaP_droop = P_supply_static - P_supply_dynamic\",\n      \"possible_faults\": &#91;\n        \"undersized tubing\",\n        \"filter regulator restriction\",\n        \"insufficient air capacity\",\n        \"excessive actuator air consumption\"\n      ]\n    },\n    \"travel_deviation\": {\n      \"equation\": \"e_x(t) = x_command(t) - x_actual(t)\",\n      \"normal_condition\": \"absolute value of e_x is less than or equal to allowable deviation\",\n      \"possible_faults\": &#91;\n        \"packing friction\",\n        \"valve sticking\",\n        \"low supply pressure\",\n        \"actuator leakage\",\n        \"positioner calibration shift\",\n        \"process force increase\",\n        \"trim damage\"\n      ]\n    },\n    \"actuator_air_force\": {\n      \"equation\": \"F_air = P_actuator * A_effective\"\n    },\n    \"friction_estimation\": {\n      \"source_status\": \"engineering interpretation for explaining the handbook diagnostic concept; not a direct handbook formula\",\n      \"opening_equation\": \"F_open(x) = F_0(x) + F_friction(x)\",\n      \"closing_equation\": \"F_close(x) = F_0(x) - F_friction(x)\",\n      \"friction_equation\": \"F_friction(x) approximately equals abs(F_open(x) - F_close(x)) \/ 2\",\n      \"baseline_force_equation\": \"F_0(x) approximately equals (F_open(x) + F_close(x)) \/ 2\",\n      \"pressure_signature_equation\": \"F_friction(x) approximately equals A_effective(x) * abs(P_open(x) - P_close(x)) \/ 2\",\n      \"validity_conditions\": &#91;\n        \"same valve travel\",\n        \"nearly identical process conditions\",\n        \"slow quasi-static movement\",\n        \"seat not in contact\",\n        \"direction reversal points excluded\"\n      ],\n      \"trend_rule\": \"increasing friction over time indicates packing, stem, guide or alignment degradation\"\n    }\n  },\n  \"bench_set\": {\n    \"definition\": \"\uc2a4\ud504\ub9c1 \uc870\uc808\uae30\uc5d0 \uc758\ud574 \uc561\ucd94\uc5d0\uc774\ud130 \uc2a4\ud504\ub9c1\uc5d0 \ubd80\uc5ec\ub418\ub294 \ucd08\uae30 \uc555\ucd95\",\n    \"spring_force_equation\": \"F_spring(x) = F_preload + k*x\",\n    \"air_force_equation\": \"F_air(x) = P_loading(x) * A_effective(x)\",\n    \"net_force_equation\": \"F_net(x) = P_loading(x) * A_effective(x) - (F_preload + k*x)\",\n    \"equivalent_spring_pressure\": \"P_spring(x) = (F_preload + k*x) \/ A_effective(x)\",\n    \"low_preload_effects\": &#91;\n      \"insufficient fail-safe force\",\n      \"insufficient seat load\",\n      \"increased shutoff leakage\"\n    ],\n    \"high_preload_effects\": &#91;\n      \"increased starting pressure\",\n      \"reduced pneumatic force margin\",\n      \"insufficient rated travel\",\n      \"slower response\"\n    ]\n  },\n  \"seat_load\": {\n    \"equation\": \"F_seat_available = F_actuator_net - F_unbalance_resist - F_packing - F_additional\",\n    \"important_note\": \"\uc2dc\ud2b8 \ud558\uc911\uc740 \uc561\ucd94\uc5d0\uc774\ud130 \uc21c \ucd94\ub825\uc5d0\uc11c \ub2e4\ub978 \uc800\ud56d \ud558\uc911\uc744 \uc0c1\uc1c4\ud55c \ud6c4 \ub0a8\ub294 \ud798\uc774\ub2e4.\"\n  },\n  \"fail_safe\": {\n    \"fail_close_equation\": \"F_spring_fail >= F_unbalance_resist + F_packing + F_additional + F_seat_min\",\n    \"direction_note\": \"\ubd88\ud3c9\ud615\ub825\uc774 Fail-Safe \ubc29\ud5a5\uc744 \ub3d5\ub294 \uacbd\uc6b0\uc5d0\ub294 \ubcf4\uc870\ub825\uc73c\ub85c \ubc18\uc601\ud55c\ub2e4.\"\n  },\n  \"valve_travel\": {\n    \"undertravel\": {\n      \"condition\": \"x_max &lt; x_rated\",\n      \"result\": \"Cv(x_max) &lt; Cv_rated and design flow cannot be achieved\"\n    },\n    \"overtravel\": {\n      \"condition\": \"x_max > x_rated\",\n      \"possible_results\": &#91;\n        \"reduced actuator seat load\",\n        \"plug and bonnet interference\",\n        \"stem or plug connection damage\",\n        \"trim damage\",\n        \"positioner calibration range deviation\"\n      ]\n    },\n    \"verification\": &#91;\n      \"x_actual_min = x_seat\",\n      \"x_actual_max = x_rated\"\n    ]\n  },\n  \"validation\": {\n    \"comparison_basis\": &#91;\n      \"as-new condition\",\n      \"last established baseline\",\n      \"initial valve signature\"\n    ],\n    \"required_checks\": &#91;\n      \"zero and span\",\n      \"rated travel\",\n      \"opening and closing response\",\n      \"packing friction\",\n      \"deadband\",\n      \"instrument air leakage\",\n      \"supply pressure droop\",\n      \"seat leakage\",\n      \"fail-open or fail-close action\"\n    ],\n    \"success_definition\": \"fault removal plus baseline performance recovery plus fail-safe verification\"\n  },\n  \"exam_answer_structure\": &#91;\n    \"\uc124\uce58 \ubd88\ub7c9\uc774 \uc694\uad6c \ucd94\ub825\uacfc \uc81c\uc5b4\uc131\ub2a5\uc5d0 \ubbf8\uce58\ub294 \uc601\ud5a5\uc744 \uc124\uba85\ud55c\ub2e4.\",\n    \"\ubc18\uc751\ud615, \uc608\ubc29\ud615 \ubc0f \uc608\uce21\ud615 \uc720\uc9c0\ubcf4\uc218\ub97c \ube44\uad50\ud55c\ub2e4.\",\n    \"Detection, Discrimination, Recovery, Validation\uc758 \ud3d0\ub8e8\ud504\ub97c \uc81c\uc2dc\ud55c\ub2e4.\",\n    \"\uacf5\uae30 \ub204\uc124, \uacf5\uae09\uc555\ub825, Travel Deviation \ubc0f \ub9c8\ucc30 \uc9c4\ub2e8\uc744 \uc124\uba85\ud55c\ub2e4.\",\n    \"Bench Set\uacfc \uc2a4\ud504\ub9c1\u00b7\uacf5\uc555\ub825\uc758 \uad00\uacc4\ub97c \uc218\uc2dd\uc73c\ub85c \uc81c\uc2dc\ud55c\ub2e4.\",\n    \"Undertravel\uacfc Overtravel\uc758 \uc601\ud5a5\uc744 \uc124\uba85\ud55c\ub2e4.\",\n    \"\uc815\ube44 \ud6c4 \uae30\uc900 \uc0c1\ud0dc\uc640 Fail-Safe \uae30\ub2a5\uc744 \uac80\uc99d\ud55c\ub2e4.\"\n  ],\n  \"keytags\": &#91;\n    \"Control Valve Diagnostics\",\n    \"Predictive Maintenance\",\n    \"Bench Set\",\n    \"Travel Deviation\",\n    \"Friction Trending\"\n  ]\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center 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