{"id":9321,"date":"2026-08-04T21:45:39","date_gmt":"2026-08-04T12:45:39","guid":{"rendered":"https:\/\/now0930.pe.kr\/wordpress\/?p=9321"},"modified":"2026-08-05T23:49:15","modified_gmt":"2026-08-05T14:49:15","slug":"cavitation-flashing-control-valve-handbook-5-11","status":"publish","type":"post","link":"https:\/\/now0930.pe.kr\/wordpress\/cavitation-flashing-control-valve-handbook-5-11\/","title":{"rendered":"Cavitation, Flashing control valve handbook 5.12"},"content":{"rendered":"\n<!-- WordPress\uc758 '\uc0ac\uc6a9\uc790 \uc815\uc758 HTML' \ube14\ub85d\uc5d0 \uadf8\ub300\ub85c \ubd99\uc5ec\ub123\uc73c\uc2ed\uc2dc\uc624.\n<html>, <head>, <body> \ud0dc\uadf8\ub294 \ud3ec\ud568\ud558\uc9c0 \uc54a\uc558\uc2b5\ub2c8\ub2e4. -->\n<style>\n.cv514-wrap{max-width:1100px;margin:0 auto;color:#1f2937;font-family:\"Noto Sans KR\",\"Noto Sans\",Arial,sans-serif;font-size:17px;line-height:1.75;word-break:keep-all}\n.cv514-wrap *{box-sizing:border-box}\n.cv514-wrap h1,.cv514-wrap h2,.cv514-wrap h3{color:#1c497a;line-height:1.35}\n.cv514-wrap h1{margin:0 0 8px;font-size:2.05rem;text-align:center}\n.cv514-wrap h2{margin:46px 0 18px;padding-bottom:8px;border-bottom:2px solid #1c497a;font-size:1.5rem}\n.cv514-wrap h3{margin:28px 0 10px;font-size:1.18rem}\n.cv514-wrap p{margin:10px 0}\n.cv514-meta{margin:0 0 30px;color:#5b6470;text-align:center}\n.cv514-toc{margin:24px 0 34px;padding:18px 24px;background:#f8fafc;border:1px solid #dbe3ec;border-radius:8px}\n.cv514-toc ol{margin:8px 0 0;padding-left:1.3rem;columns:2;column-gap:30px}\n.cv514-toc li{break-inside:avoid;margin:4px 0}\n.cv514-toc a{color:#1c497a;text-decoration:none}\n.cv514-box{margin:20px 0;padding:18px 20px;border:1px solid;border-radius:8px}\n.cv514-box-title{display:block;margin-bottom:8px}\n.cv514-key{background:#ebf3fb;border-color:#1c497a}\n.cv514-solution{background:#edf7ef;border-color:#2f6f45}\n.cv514-note{background:#fff9e0;border-color:#b7791f}\n.cv514-warning{background:#fdeeee;border-color:#c53030}\n.cv514-eq{margin:18px 0;padding:14px 18px;overflow-x:auto;border:1px solid #cbd5e1;border-radius:7px;background:#f8fafc;font-family:\"Times New Roman\",serif;font-size:1.05rem;text-align:center}\n.cv514-eq .line{display:block;margin:4px 0}\n.cv514-flow{padding-left:1.5rem}\n.cv514-flow li{margin:8px 0;padding:9px 12px;border-left:4px solid #1c497a;background:#eef5fb}\n.cv514-table-wrap{width:100%;margin:18px 0 26px;overflow-x:auto}\n.cv514-wrap table{width:100%;min-width:680px;border-collapse:collapse;font-size:.94rem}\n.cv514-wrap th,.cv514-wrap td{padding:10px 12px;border:1px solid #cbd5e1;vertical-align:top;text-align:left}\n.cv514-wrap th{background:#ebf3fb;color:#163b61}\n.cv514-wrap ul,.cv514-wrap ol{padding-left:1.45rem}\n.cv514-wrap li{margin:5px 0}\n.cv514-profile-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:20px 0}\n.cv514-profile{padding:16px;border:1px solid #cbd5e1;border-radius:8px;background:#fff}\n.cv514-profile-title{font-weight:700;color:#1c497a;margin-bottom:8px}\n.cv514-chart{position:relative;height:230px;border-left:2px solid #64748b;border-bottom:2px solid #64748b;margin:18px 18px 28px 38px}\n.cv514-vapor{position:absolute;left:0;right:0;top:55%;border-top:2px dashed #b45309}\n.cv514-vapor-label{position:absolute;right:-5px;top:calc(55% - 14px);font-family:\"Times New Roman\",serif}\n.cv514-curve{position:absolute;inset:0}\n.cv514-curve svg{width:100%;height:100%;overflow:visible}\n.cv514-axis-x{position:absolute;left:50%;bottom:-28px;transform:translateX(-50%);font-size:.88rem}\n.cv514-axis-y{position:absolute;left:-42px;top:50%;transform:rotate(-90deg) translateY(-50%);transform-origin:center;font-size:.88rem}\n.cv514-label{position:absolute;font-family:\"Times New Roman\",serif;font-weight:700}\n.cv514-p1{left:4%;top:5%}.cv514-pvc{left:38%;bottom:6%}.cv514-p2{right:4%;top:26%}\n.cv514-profile.flashing .cv514-p2{top:62%}\n.cv514-caption{text-align:center;font-weight:700}\n@media(max-width:760px){\n  .cv514-wrap{font-size:16px}\n  .cv514-wrap h1{font-size:1.65rem}\n  .cv514-toc ol{columns:1}\n  .cv514-profile-grid{grid-template-columns:1fr}\n}\n<\/style>\n\n<div class=\"cv514-wrap\">\n  <h1>Control Valve Handbook 5.14<br>Cavitation\uacfc Flashing<\/h1>\n  <p class=\"cv514-meta\">\uc561\uccb4 \uc81c\uc5b4\ubc38\ube0c\uc758 \uc0c1\ubcc0\ud654, \uc190\uc0c1 \uba54\ucee4\ub2c8\uc998 \ubc0f \uc120\uc815 \ub300\ucc45<\/p>\n\n  <nav class=\"cv514-toc\" aria-label=\"\ubaa9\ucc28\">\n    <strong>\ubaa9\ucc28<\/strong>\n    <ol>\n      <li><a href=\"#cv514-overview\">\uac1c\uc694<\/a><\/li>\n      <li><a href=\"#cv514-choked\">Choked Flow\uc640 \uae30\ud3ec \ubc1c\uc0dd<\/a><\/li>\n      <li><a href=\"#cv514-profile\">\uc555\ub825 \ud504\ub85c\ud30c\uc77c\uacfc \ud310\ubcc4<\/a><\/li>\n      <li><a href=\"#cv514-compare\">Cavitation\uacfc Flashing \ube44\uad50<\/a><\/li>\n      <li><a href=\"#cv514-recovery\">Pressure Recovery\uc640 \ubc38\ube0c \ud615\uc2dd<\/a><\/li>\n      <li><a href=\"#cv514-flashing\">Flashing Service\uc758 \ubc38\ube0c \uc120\uc815<\/a><\/li>\n      <li><a href=\"#cv514-cavitation\">Cavitation Service\uc758 \ub300\ucc45<\/a><\/li>\n      <li><a href=\"#cv514-procedure\">\uc120\uc815 \ubc0f \uac80\ud1a0 \uc808\ucc28<\/a><\/li>\n      <li><a href=\"#cv514-summary\">\uae30\uc220\uc0ac \ub2f5\uc548\uc6a9 \ud575\uc2ec \uc815\ub9ac<\/a><\/li>\n    <\/ol>\n  <\/nav>\n<h2 id=\"cv514-overview\">\uac1c\uc694<\/h2>\n<p>\uc561\uccb4\uac00 \uc81c\uc5b4\ubc38\ube0c\uc758 \uc81c\ud55c\ubd80\ub97c \ud1b5\uacfc\ud558\uba74 \uc720\ub85c\uac00 \uc218\ucd95\ud558\uace0 \uc720\uc18d\uc774 \uc99d\uac00\ud55c\ub2e4. \uc2e4\uc81c \uc720\uccb4\uc758 \ucd5c\uc18c \ub2e8\uba74\uc801\uc740 \ubb3c\ub9ac\uc801 \uc81c\ud55c\ubd80 \ubc14\ub85c \ud558\ub958\uc758 <strong>Vena Contracta<\/strong>\uc5d0\uc11c \ud615\uc131\ub41c\ub2e4. \uc774 \uc9c0\uc810\uc5d0\uc11c\ub294 \uc720\uc18d\uc774 \ucd5c\ub300\uc774\uace0 \uc815\uc555\uc774 \ucd5c\uc18c\uac00 \ub41c\ub2e4.<\/p>\n<div class=\"cv514-box cv514-key\"><strong class=\"cv514-box-title\">\ud575\uc2ec<\/strong><div class=\"cv514-eq\">\uc720\ub85c \uc218\ucd95 \u2192 \uc720\uc18d \uc99d\uac00 \u2192 P<sub>vc<\/sub> \uac10\uc18c \u2192 \uc99d\uae30 \uae30\ud3ec \ubc1c\uc0dd \uac00\ub2a5<\/div><\/div>\n<p>\ubc38\ube0c \ud558\ub958\uc5d0\uc11c \uc720\ub85c\uac00 \ud655\ub300\ub418\uba74 \uc720\uc18d\uc740 \uac10\uc18c\ud558\uace0 \uc555\ub825\uc740 \uc77c\ubd80 \ud68c\ubcf5\ub41c\ub2e4. \uadf8\ub7ec\ub098 \uc5d0\ub108\uc9c0\uac00 \ubc38\ube0c\uc5d0\uc11c \uc18c\uc0b0\ub418\ubbc0\ub85c \ud558\ub958\uc555\ub825\uc740 \uc785\uad6c\uc555\ub825\uae4c\uc9c0 \uc644\uc804\ud788 \ud68c\ubcf5\ub418\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n<div class=\"cv514-eq\">P<sub>1<\/sub> \u2192 P<sub>vc<\/sub> \u2192 P<sub>2<\/sub>, &nbsp;&nbsp; P<sub>1<\/sub> &gt; P<sub>2<\/sub><\/div>\n<ul><li>P<sub>1<\/sub>: \ubc38\ube0c \uc785\uad6c\uc555\ub825<\/li><li>P<sub>vc<\/sub>: Vena Contracta \uc555\ub825<\/li><li>P<sub>2<\/sub>: \ubc38\ube0c \ucd9c\uad6c\uc555\ub825<\/li><li>P<sub>v<\/sub>: \uc6b4\uc804\uc628\ub3c4\uc5d0\uc11c \uc561\uccb4\uc758 \uc99d\uae30\uc555<\/li><\/ul>\n<h2 id=\"cv514-choked\">Choked Flow\uc640 \uae30\ud3ec \ubc1c\uc0dd<\/h2>\n<p>IEC \uc561\uccb4 \uc0ac\uc774\uc9d5\uc5d0\uc11c\ub294 \uc561\uccb4 \uc720\ub3d9\uc774 \ucd08\ud06c\ub418\ub294 \ud55c\uacc4 \uc555\ub825\uac15\ud558\ub97c \u0394P<sub>choked<\/sub>\ub85c \uacc4\uc0b0\ud55c\ub2e4.<\/p>\n<div class=\"cv514-eq\">\u0394P<sub>actual<\/sub> = P<sub>1<\/sub> \u2212 P<sub>2<\/sub><\/div>\n<div class=\"cv514-box cv514-warning\"><strong class=\"cv514-box-title\">\uacbd\uace0<\/strong><div class=\"cv514-eq\">\u0394P<sub>actual<\/sub> &gt; \u0394P<sub>choked<\/sub> \u21d2 Cavitation \ub610\ub294 Flashing \uac00\ub2a5<\/div><p>\uc774 \uc870\uac74\uc5d0\uc11c\ub294 \ubc38\ube0c\ubfd0 \uc544\ub2c8\ub77c \uc778\uc811 \ud558\ub958 \ubc30\uad00\uc5d0\ub3c4 \uc190\uc0c1\uc774 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.<\/p><\/div>\n<p>\uae30\ud3ec\uac00 \uc0dd\uc131\ub418\ub294 \uc9c1\uc811 \uc870\uac74\uc740 Vena Contracta \uc555\ub825\uc774 \uc99d\uae30\uc555\ubcf4\ub2e4 \ub0ae\uc544\uc9c0\ub294 \uac83\uc774\ub2e4.<\/p>\n<div class=\"cv514-eq\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub><\/div>\n<p>\uc774 \ub2e8\uacc4\uae4c\uc9c0\ub294 Cavitation\uacfc Flashing\uc774 \ub3d9\uc77c\ud558\ub2e4. \ub450 \ud604\uc0c1\uc740 \uc555\ub825\ud68c\ubcf5 \ud6c4 \ucd9c\uad6c\uc555\ub825 P<sub>2<\/sub>\uac00 \uc99d\uae30\uc555 P<sub>v<\/sub>\ubcf4\ub2e4 \ub192\uc740\uc9c0 \ub0ae\uc740\uc9c0\uc5d0 \ub530\ub77c \uad6c\ubd84\ud55c\ub2e4.<\/p>\n<h2 id=\"cv514-profile\">\uc555\ub825 \ud504\ub85c\ud30c\uc77c\uacfc \ud310\ubcc4<\/h2>\n\n<div class=\"cv514-profile-grid\">\n  <div class=\"cv514-profile\">\n    <div class=\"cv514-profile-title\">Cavitation \uc555\ub825 \ud504\ub85c\ud30c\uc77c<\/div>\n    <div class=\"cv514-chart\">\n      <div class=\"cv514-vapor\"><\/div>\n      <div class=\"cv514-vapor-label\">P<sub>v<\/sub><\/div>\n      <div class=\"cv514-curve\">\n        <svg viewBox=\"0 0 100 100\" preserveAspectRatio=\"none\" aria-label=\"Cavitation \uc555\ub825 \uace1\uc120\">\n          <polyline points=\"0,12 20,16 42,82 62,30 100,36\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2.8\"\/>\n          <line x1=\"42\" y1=\"82\" x2=\"42\" y2=\"100\" stroke=\"#94a3b8\" stroke-width=\"1.4\" stroke-dasharray=\"3 3\"\/>\n        <\/svg>\n      <\/div>\n      <span class=\"cv514-label cv514-p1\">P<sub>1<\/sub><\/span>\n      <span class=\"cv514-label cv514-pvc\">P<sub>vc<\/sub><\/span>\n      <span class=\"cv514-label cv514-p2\">P<sub>2<\/sub><\/span>\n      <span class=\"cv514-axis-x\">\ubc38\ube0c \ud1b5\uacfc \uc704\uce58<\/span>\n      <span class=\"cv514-axis-y\">\uc555\ub825<\/span>\n    <\/div>\n    <div class=\"cv514-caption\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub> &lt; P<sub>2<\/sub><\/div>\n  <\/div>\n\n  <div class=\"cv514-profile flashing\">\n    <div class=\"cv514-profile-title\">Flashing \uc555\ub825 \ud504\ub85c\ud30c\uc77c<\/div>\n    <div class=\"cv514-chart\">\n      <div class=\"cv514-vapor\"><\/div>\n      <div class=\"cv514-vapor-label\">P<sub>v<\/sub><\/div>\n      <div class=\"cv514-curve\">\n        <svg viewBox=\"0 0 100 100\" preserveAspectRatio=\"none\" aria-label=\"Flashing \uc555\ub825 \uace1\uc120\">\n          <polyline points=\"0,12 20,16 42,82 62,66 100,70\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2.8\"\/>\n          <line x1=\"42\" y1=\"82\" x2=\"42\" y2=\"100\" stroke=\"#94a3b8\" stroke-width=\"1.4\" stroke-dasharray=\"3 3\"\/>\n        <\/svg>\n      <\/div>\n      <span class=\"cv514-label cv514-p1\">P<sub>1<\/sub><\/span>\n      <span class=\"cv514-label cv514-pvc\">P<sub>vc<\/sub><\/span>\n      <span class=\"cv514-label cv514-p2\">P<sub>2<\/sub><\/span>\n      <span class=\"cv514-axis-x\">\ubc38\ube0c \ud1b5\uacfc \uc704\uce58<\/span>\n      <span class=\"cv514-axis-y\">\uc555\ub825<\/span>\n    <\/div>\n    <div class=\"cv514-caption\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub>, P<sub>2<\/sub> &lt; P<sub>v<\/sub><\/div>\n  <\/div>\n<\/div>\n\n<h3>Cavitation<\/h3>\n<div class=\"cv514-eq\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub> &lt; P<sub>2<\/sub><\/div>\n<p>Vena Contracta\uc5d0\uc11c \uc0dd\uc131\ub41c \uc99d\uae30 \uae30\ud3ec\ub294 \ud558\ub958\uc758 \uc555\ub825\ud68c\ubcf5 \uad6c\uac04\uc5d0\uc11c \ubd95\uad34\ud55c\ub2e4.<\/p>\n<p>\uae30\ud3ec \ubd95\uad34 \uc5d0\ub108\uc9c0\uac00 \ubc38\ube0c \ud45c\uba74 \uac00\uae4c\uc774\uc5d0\uc11c \ubc29\ucd9c\ub418\uba74 \uc7ac\ub8cc\uac00 \uad6d\ubd80\uc801\uc73c\ub85c \ud0c8\ub77d\ud55c\ub2e4.<\/p>\n<h3>Flashing<\/h3>\n<div class=\"cv514-eq\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub>, &nbsp;&nbsp; P<sub>2<\/sub> &lt; P<sub>v<\/sub><\/div>\n<p>\ucd9c\uad6c\uc555\ub825\uc774 \uc99d\uae30\uc555\ubcf4\ub2e4 \ub0ae\uc73c\ubbc0\ub85c \uc0dd\uc131\ub41c \uae30\ud3ec\uac00 \ubd95\uad34\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n<p>\ud558\ub958 \uc720\ub3d9\uc740 \uc561\uccb4\uc640 \uc99d\uae30\uac00 \ud63c\uc7ac\ub41c \uace0\uc18d 2\uc0c1 \uc720\ub3d9\uc774 \ub41c\ub2e4.<\/p>\n<h2 id=\"cv514-compare\">Cavitation\uacfc Flashing \ube44\uad50<\/h2>\n<div class=\"cv514-table-wrap\"><table><thead><tr><th>\ud56d\ubaa9<\/th><th>Cavitation<\/th><th>Flashing<\/th><\/tr><\/thead><tbody><tr><td>\uae30\ud3ec \ubc1c\uc0dd<\/td><td>P<sub>vc<\/sub> &lt; P<sub>v<\/sub><\/td><td>P<sub>vc<\/sub> &lt; P<sub>v<\/sub><\/td><\/tr><tr><td>\ucd9c\uad6c\uc555\ub825<\/td><td>P<sub>2<\/sub> &gt; P<sub>v<\/sub><\/td><td>P<sub>2<\/sub> &lt; P<sub>v<\/sub><\/td><\/tr><tr><td>\uae30\ud3ec \uac70\ub3d9<\/td><td>\uc555\ub825\ud68c\ubcf5 \ud6c4 \ubd95\uad34<\/td><td>\ud558\ub958\uae4c\uc9c0 \uc9c0\uc18d<\/td><\/tr><tr><td>\uc720\ub3d9\uc0c1\ud0dc<\/td><td>\uae30\ud3ec \uc0dd\uc131 \ud6c4 \uc7ac\uc751\ucd95<\/td><td>\uc561\uccb4\u2013\uc99d\uae30 2\uc0c1 \uc720\ub3d9<\/td><\/tr><tr><td>\uc8fc\uc694 \uc190\uc0c1\uc6d0\ub9ac<\/td><td>\uae30\ud3ec \ubd95\uad34 \uc5d0\ub108\uc9c0<\/td><td>\uace0\uc18d \uc561\uc801 \ubc0f 2\uc0c1 \uc720\ub3d9\uc758 \uce68\uc2dd<\/td><\/tr><tr><td>\uc190\uc0c1 \ud45c\uba74<\/td><td>\uac70\uce60\uace0 \ub2e4\uacf5\uc9c8\uc778 cinder-like \ud615\uc0c1<\/td><td>\ub9e4\ub044\ub7fd\uace0 \uad11\ud0dd\uc774 \uc788\ub294 polished \ud615\uc0c1<\/td><\/tr><tr><td>\ub300\ud45c \uc18c\uc74c<\/td><td>\uc790\uac08\uc774 \ud750\ub974\ub294 \uac83\uacfc \uc720\uc0ac\ud55c \uc18c\uc74c<\/td><td>5.14\uc5d0\uc11c\ub294 \uace0\uc720\ud55c \uc18c\uc74c \ud615\ud0dc\ub97c \ubcc4\ub3c4\ub85c \uc81c\uc2dc\ud558\uc9c0 \uc54a\uc74c<\/td><\/tr><tr><td>\uc190\uc0c1 \uc704\uce58<\/td><td>\ud2b8\ub9bc, \ubc14\ub514 \ubc0f \uc555\ub825\ud68c\ubcf5\uc774 \uc77c\uc5b4\ub098\ub294 \ud558\ub958 \ubc30\uad00<\/td><td>\ucd5c\uace0 \uc720\uc18d\ubd80, \uc8fc\ub85c \ud50c\ub7ec\uadf8\uc640 \uc2dc\ud2b8\ub9c1\uc758 seat line \ubd80\uadfc<\/td><\/tr><tr><td>\ubc38\ube0c\uc5d0 \uc758\ud55c \uadfc\ubcf8 \uc608\ubc29<\/td><td>\uac00\ub2a5: \uc555\ub825\uac15\ud558 \ubd84\ud560 \ub4f1<\/td><td>\ubd88\uac00\ub2a5: P<sub>2<\/sub>\uc640 P<sub>v<\/sub>\uac00 \uacf5\uc815\uc870\uac74\uc73c\ub85c \uacb0\uc815\ub428<\/td><\/tr><\/tbody><\/table><\/div>\n<h2 id=\"cv514-recovery\">Pressure Recovery\uc640 \ubc38\ube0c \ud615\uc2dd<\/h2>\n<p>\ubc38\ube0c \ud615\uc0c1\uc5d0 \ub530\ub77c Vena Contracta \uc774\ud6c4\uc758 \uc555\ub825\ud68c\ubcf5 \uc815\ub3c4\uac00 \ub2ec\ub77c\uc9c4\ub2e4.<\/p>\n<ul><li><strong>High-recovery valve<\/strong>: P<sub>vc<\/sub>\uac00 \ub354 \ub0ae\uc544\uc9c8 \uc218 \uc788\uc5b4 Cavitation\uc5d0 \ub354 \ucde8\uc57d\ud558\ub2e4.<\/li><li><strong>Low-recovery valve<\/strong>: \ub0b4\ubd80 \ub09c\ub958\uc640 \uc5d0\ub108\uc9c0 \uc18c\uc0b0\uc774 \ucee4 \uc555\ub825\ud68c\ubcf5\ub7c9\uc774 \uc0c1\ub300\uc801\uc73c\ub85c \uc791\ub2e4.<\/li><\/ul>\n<div class=\"cv514-box cv514-note\"><strong class=\"cv514-box-title\">\uc8fc\uc758<\/strong><p>High recovery\ub77c\ub294 \ud45c\ud604\uc740 \ub2e8\uc21c\ud788 \uc555\ub825 \uc190\uc2e4\uc774 \uc791\ub2e4\ub294 \uc758\ubbf8\ub9cc\uc740 \uc544\ub2c8\ub2e4.<\/p><p>Vena Contracta \uc555\ub825\uc774 \ub354 \ub0ae\uc544\uc9c8 \uc218 \uc788\uc73c\ubbc0\ub85c \uc561\uccb4\uc758 \uc99d\uae30\uc555 \uc774\ud558\ub85c \ub0b4\ub824\uac08 \uac00\ub2a5\uc131\uc774 \ucee4\uc9c4\ub2e4.<\/p><\/div>\n<h2 id=\"cv514-flashing\">Flashing Service\uc758 \ubc38\ube0c \uc120\uc815<\/h2>\n<p>Flashing\uc740 P<sub>2<\/sub> &lt; P<sub>v<\/sub>\uc778 \uacf5\uc815\uc870\uac74\uc5d0\uc11c \ubc1c\uc0dd\ud55c\ub2e4.<\/p>\n<p>P<sub>2<\/sub>\ub294 \ud558\ub958 \uacf5\uc815\uacfc \ubc30\uad00\uc774 \uacb0\uc815\ud558\uace0, P<sub>v<\/sub>\ub294 \uc720\uccb4\uc640 \uc6b4\uc804\uc628\ub3c4\uac00 \uacb0\uc815\ud55c\ub2e4. \ub530\ub77c\uc11c \uc81c\uc5b4\ubc38\ube0c \uc790\uccb4\ub85c Flashing\uc744 \uc81c\uac70\ud560 \uc218 \uc5c6\ub2e4.<\/p>\n<div class=\"cv514-box cv514-warning\"><strong class=\"cv514-box-title\">\uacbd\uace0<\/strong><div class=\"cv514-eq\">Flashing\uc740 \ubc38\ube0c\ub85c \ubc29\uc9c0\ud558\ub294 \ubb38\uc81c\uac00 \uc544\ub2c8\ub77c \uce68\uc2dd \uc190\uc0c1\uc744 \ucd5c\uc18c\ud654\ud558\ub294 \ubb38\uc81c\uc774\ub2e4.<\/div><\/div>\n<p>\uce68\uc2dd \uc800\uac10\uc758 \uae30\ubcf8 \uc6d0\uce59\uc740 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n<ol class=\"\"><li>\uc561\uc801\uc774 \ubc38\ube0c \ud45c\uba74\uc5d0 \ucda9\ub3cc\ud558\ub294 \ud69f\uc218\ub97c \uc904\uc778\ub2e4.<\/li><li>\ucda9\ub3cc\ud558\ub294 \ud45c\uba74\uc5d0 \uac00\ub2a5\ud55c \ud55c \ub2e8\ub2e8\ud55c \uc7ac\ub8cc\ub97c \uc801\uc6a9\ud55c\ub2e4.<\/li><li>\uc2a4\ub85c\ud2c0\ub9c1 \ud558\ub958\uc758 \uc720\ub85c \uba74\uc801\uc744 \ud655\ub300\ud558\uc5ec 2\uc0c1 \uc720\ub3d9 \uc18d\ub3c4\ub97c \ub0ae\ucd98\ub2e4.<\/li><li>\uc720\ub3d9 \ubc29\ud5a5 \ubcc0\ud654\uac00 \uc801\uc740 \ubc38\ube0c \ud615\uc0c1\uc744 \uc120\uc815\ud55c\ub2e4.<\/li><\/ol>\n<p>\uad8c\uc7a5\ub418\ub294 \ud615\uc0c1\uc740 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n<ul><li>Sliding-stem angle valve<\/li><li>Eccentric rotary plug valve<\/li><li>Segmented ball valve<\/li><li>Expanded outlet \ub610\ub294 \ud655\ub300\ub41c \ud558\ub958 \uc720\ub85c\ub97c \uac00\uc9c4 \ubc38\ube0c<\/li><\/ul>\n<p>Flashing\uacfc \ubd80\uc2dd\uc774 \ub3d9\uc2dc\uc5d0 \uc874\uc7ac\ud558\uba74 \uc190\uc0c1\uc774 \uc0c1\uc2b9\uc791\uc6a9\uc744 \uc77c\uc73c\ud0a8\ub2e4.<\/p>\n<p>\uc608\ub97c \ub4e4\uc5b4 \ubb3c\uacfc \ud0c4\uc18c\uac15\uc758 \uc870\ud569\uc5d0\uc11c\ub294 \ubd80\uc2dd\uc73c\ub85c \ud615\uc131\ub41c \uc5f0\ud55c \uc0b0\ud654\uce35\uc744 Flashing \uc720\ub3d9\uc774 \ubc18\ubcf5\uc801\uc73c\ub85c \uc81c\uac70\ud560 \uc218 \uc788\ub2e4. \uc774 \uacbd\uc6b0 \ubd80\uc2dd \uc5b5\uc81c\ub97c \uace0\ub824\ud55c \uc7ac\uc9c8 \uc120\uc815\uc774 \ud544\uc694\ud558\ub2e4.<\/p>\n<h2 id=\"cv514-cavitation\">Cavitation Service\uc758 \ub300\ucc45<\/h2>\n<p>Cavitation\uc740 \ub2e4\uc74c \uc138 \uac00\uc9c0 \ubc29\ubc95\uc73c\ub85c \ub300\uc751\ud55c\ub2e4.<\/p>\n<h3>\ubc29\ubc95 1: Cavitation \uc81c\uac70<\/h3>\n<p>\uc804\uccb4 \uc555\ub825\uac15\ud558\ub97c \ub2e4\ub2e8 \ud2b8\ub9bc\uc73c\ub85c \uc5ec\ub7ec \ub2e8\uacc4\uc5d0 \ubd84\ubc30\ud55c\ub2e4.<\/p>\n<div class=\"cv514-eq\">\u0394P<sub>total<\/sub> = \u0394P<sub>1<\/sub> + \u0394P<sub>2<\/sub> + \u00b7\u00b7\u00b7 + \u0394P<sub>n<\/sub><\/div>\n<p>\uac01 \ub2e8\uacc4\uc758 \uad6d\ubd80 \ucd5c\uc800\uc555\ub825\uc774 \uc99d\uae30\uc555\ubcf4\ub2e4 \ub192\ub3c4\ub85d \uc720\uc9c0\ud55c\ub2e4.<\/p>\n<div class=\"cv514-eq\">P<sub>vc,i<\/sub> &gt; P<sub>v<\/sub> &nbsp;&nbsp; for all stages i<\/div>\n<p>\uadf8\ub7ec\uba74 \uc99d\uae30 \uae30\ud3ec\uac00 \uc0dd\uc131\ub418\uc9c0 \uc54a\uc73c\ubbc0\ub85c \ubd95\uad34\ub3c4 \ubc1c\uc0dd\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n<h3>\ubc29\ubc95 2: \uc190\uc0c1 \uaca9\ub9ac \ubc0f \ucd5c\uc18c\ud654<\/h3>\n<p>Cavitation \uc790\uccb4\ub97c \uc644\uc804\ud788 \uc81c\uac70\ud558\uc9c0 \ubabb\ud558\uba74 \ub2e4\uc74c \ubc29\ubc95\uc744 \uc801\uc6a9\ud55c\ub2e4.<\/p>\n<ul><li>\uae30\ud3ec \ubd95\uad34 \uc601\uc5ed\uc744 \ubc38\ube0c\uc758 \uc8fc\uc694 \ud45c\uba74\uc5d0\uc11c \uaca9\ub9ac\ud55c\ub2e4.<\/li><li>Cavitation\uc758 \uc601\ud5a5\uc744 \ubc1b\ub294 \ud45c\uba74\uc744 \uacbd\ud654\ud55c\ub2e4.<\/li><li>\ubc38\ube0c \ud45c\uba74\uc5d0 \uc804\ub2ec\ub418\ub294 \ubd95\uad34 \ucda9\uaca9\uc744 \ucd5c\uc18c\ud654\ud55c\ub2e4.<\/li><\/ul>\n<h3>\ubc29\ubc95 3: \uc2dc\uc2a4\ud15c \uc870\uac74 \ubcc0\uacbd<\/h3>\n<p>\ud558\ub958\uc555\ub825 P<sub>2<\/sub>\ub97c \ub192\uc5ec Vena Contracta \uc555\ub825\uc774 \uc99d\uae30\uc555 \uc774\ud558\ub85c \ub0b4\ub824\uac00\uc9c0 \uc54a\ub3c4\ub85d \ud55c\ub2e4.<\/p>\n<ul><li>\ubc38\ube0c\ub97c \ud558\ub958 \uc815\uc555\uc218\ub450\uac00 \ub354 \ud070 \uc704\uce58\ub85c \uc774\ub3d9\ud55c\ub2e4.<\/li><li>\uc624\ub9ac\ud53c\uc2a4 \ud50c\ub808\uc774\ud2b8 \ub610\ub294 Backpressure Device\ub97c \uc801\uc6a9\ud55c\ub2e4.<\/li><li>\ubc30\uad00\uacfc \uacf5\uc815\uc870\uac74\uc744 \ubcc0\uacbd\ud558\uc5ec \ubc38\ube0c \uc555\ub825\uac15\ud558\ub97c \uc904\uc778\ub2e4.<\/li><\/ul>\n<div class=\"cv514-box cv514-note\"><strong class=\"cv514-box-title\">\uc8fc\uc758<\/strong><p>Backpressure Device\ub97c \uc801\uc6a9\ud558\uba74 \ubc38\ube0c\uc758 Cavitation\uc740 \uc904\uc5b4\ub4e4 \uc218 \uc788\ub2e4.<\/p><p>\uadf8\ub7ec\ub098 Cavitation \uc704\uce58\uac00 \uc624\ub9ac\ud53c\uc2a4\uc640 \uac19\uc740 \ud558\ub958 \uc81c\ud55c\uc7a5\uce58\ub85c \uc774\ub3d9\ud560 \uc218 \uc788\uc73c\ubbc0\ub85c \uc2dc\uc2a4\ud15c \uc804\uccb4\ub97c \uac80\ud1a0\ud574\uc57c \ud55c\ub2e4.<\/p><\/div>\n<h2 id=\"cv514-procedure\">\uc120\uc815 \ubc0f \uac80\ud1a0 \uc808\ucc28<\/h2>\n<ol class=\"\"><li>\uc785\uad6c\uc555\ub825 P<sub>1<\/sub>, \ucd9c\uad6c\uc555\ub825 P<sub>2<\/sub>, \uc6b4\uc804\uc628\ub3c4 \ubc0f \uc99d\uae30\uc555 P<sub>v<\/sub>\ub97c \ud655\uc778\ud55c\ub2e4.<\/li><li>\uc2e4\uc81c \uc555\ub825\uac15\ud558\ub97c \uacc4\uc0b0\ud55c\ub2e4: \u0394P<sub>actual<\/sub> = P<sub>1<\/sub> \u2212 P<sub>2<\/sub>.<\/li><li>IEC \uc561\uccb4 \uc0ac\uc774\uc9d5\uc73c\ub85c \u0394P<sub>choked<\/sub>\ub97c \ud655\uc778\ud55c\ub2e4.<\/li><li>\u0394P<sub>actual<\/sub> &gt; \u0394P<sub>choked<\/sub>\uc774\uba74 \ucd08\ud06c \uc720\ub3d9\uacfc \uc0c1\ubcc0\ud654 \uac00\ub2a5\uc131\uc744 \uac80\ud1a0\ud55c\ub2e4.<\/li><li>P<sub>vc<\/sub> &lt; P<sub>v<\/sub>\uc778\uc9c0 \ud655\uc778\ud558\uc5ec \uae30\ud3ec \ubc1c\uc0dd \uac00\ub2a5\uc131\uc744 \ud310\ub2e8\ud55c\ub2e4.<\/li><li>P<sub>2<\/sub> &gt; P<sub>v<\/sub>\uc774\uba74 Cavitation, P<sub>2<\/sub> &lt; P<sub>v<\/sub>\uc774\uba74 Flashing\uc73c\ub85c \uad6c\ubd84\ud55c\ub2e4.<\/li><li>Cavitation\uc774\uba74 \ub2e4\ub2e8 \uac10\uc555, \uc190\uc0c1 \uaca9\ub9ac \ub610\ub294 P<sub>2<\/sub> \uc0c1\uc2b9 \ubc29\uc548\uc744 \uac80\ud1a0\ud55c\ub2e4.<\/li><li>Flashing\uc774\uba74 \uc9c1\uc120 \uc720\ub85c, \ud655\ub300 \ucd9c\uad6c, \uc18d\ub3c4 \uc800\uac10 \ubc0f \uacbd\uc9c8\uc7ac\ub8cc\ub97c \uc801\uc6a9\ud55c\ub2e4.<\/li><li>\ud2b8\ub9bc\ubfd0 \uc544\ub2c8\ub77c \ubc38\ube0c \ubc14\ub514\uc640 \uc778\uc811 \ud558\ub958 \ubc30\uad00\uc758 \uc190\uc0c1 \uac00\ub2a5\uc131\uc744 \ud655\uc778\ud55c\ub2e4.<\/li><li>\ubd80\uc2dd\uacfc \uce68\uc2dd\uc758 \ubcf5\ud569\uc791\uc6a9\uc744 \uace0\ub824\ud558\uc5ec \ubc14\ub514\uc640 \ud2b8\ub9bc \uc7ac\uc9c8\uc744 \uc120\uc815\ud55c\ub2e4.<\/li><\/ol>\n<h2 id=\"cv514-summary\">\uae30\uc220\uc0ac \ub2f5\uc548\uc6a9 \ud575\uc2ec \uc815\ub9ac<\/h2>\n<div class=\"cv514-box cv514-key\"><strong class=\"cv514-box-title\">\ud575\uc2ec<\/strong><p>\uc561\uccb4\uac00 \uc81c\uc5b4\ubc38\ube0c\uc758 \uc81c\ud55c\ubd80\ub97c \ud1b5\uacfc\ud558\uba74 Vena Contracta\uc5d0\uc11c \uc720\uc18d\uc774 \ucd5c\ub300\uac00 \ub418\uace0 \uc555\ub825\uc774 \ucd5c\uc18c\uac00 \ub41c\ub2e4.<\/p><p>P<sub>vc<\/sub> &lt; P<sub>v<\/sub>\uac00 \ub418\uba74 \uc99d\uae30 \uae30\ud3ec\uac00 \ubc1c\uc0dd\ud55c\ub2e4.<\/p><p>\uc774\ud6c4 \ucd9c\uad6c\uc555\ub825\uc774 \uc99d\uae30\uc555\ubcf4\ub2e4 \ub192\uc544 \uae30\ud3ec\uac00 \ubd95\uad34\ud558\uba74 Cavitation\uc774\uace0, \ucd9c\uad6c\uc555\ub825\uc774 \uc99d\uae30\uc555\ubcf4\ub2e4 \ub0ae\uc544 \uae30\ud3ec\uac00 \ud558\ub958\uae4c\uc9c0 \uc720\uc9c0\ub418\uba74 Flashing\uc774\ub2e4.<\/p><\/div>\n<div class=\"cv514-eq\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub> &lt; P<sub>2<\/sub> \u21d2 Cavitation<\/div>\n<div class=\"cv514-eq\">P<sub>vc<\/sub> &lt; P<sub>v<\/sub>, &nbsp;&nbsp; P<sub>2<\/sub> &lt; P<sub>v<\/sub> \u21d2 Flashing<\/div>\n<div class=\"cv514-box cv514-solution\"><strong class=\"cv514-box-title\">\uacb0\ub860<\/strong><p>Cavitation\uc740 \uc804\uccb4 \uc555\ub825\uac15\ud558\ub97c \ub2e4\ub2e8 \ud2b8\ub9bc\uc73c\ub85c \ubd84\ud560\ud558\uc5ec \uac01 \ub2e8\uacc4\uc758 \ucd5c\uc800\uc555\ub825\uc744 \uc99d\uae30\uc555 \uc774\uc0c1\uc73c\ub85c \uc720\uc9c0\ud558\uba74 \ubc29\uc9c0\ud560 \uc218 \uc788\ub2e4.<\/p><p>\ubc18\uba74 Flashing\uc740 \ud558\ub958\uc555\ub825\uacfc \uc99d\uae30\uc555\uc774 \uacb0\uc815\ud558\ub294 \uacf5\uc815\ud604\uc0c1\uc774\ubbc0\ub85c \ubc38\ube0c \uc790\uccb4\ub85c \uc81c\uac70\ud560 \uc218 \uc5c6\ub2e4.<\/p><p>\ub530\ub77c\uc11c \uc9c1\uc120 \uc720\ub85c, \ud655\ub300\ub41c \ud558\ub958 \uc720\ub85c, \uc18d\ub3c4 \uc800\uac10 \ubc0f \uacbd\uc9c8\uc7ac\ub8cc\ub97c \uc801\uc6a9\ud558\uc5ec \uce68\uc2dd \uc190\uc0c1\uc744 \ucd5c\uc18c\ud654\ud574\uc57c \ud55c\ub2e4.<\/p><\/div>\n<h2 id=\"cv514-reference\">\ucc38\uace0\uc790\ub8cc<\/h2>\n<ul><li>Emerson, <em>Control Valve Handbook<\/em>, Sixth Edition, Section 5.14.<\/li><\/ul>\n<\/div>\n\n\n\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-2.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"valve\uc758 \uc0bd\uc785.\"><\/object><a id=\"wp-block-file--media-68d9b3a4-ce01-4e48-8c23-d5c274668dfe\" href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/08\/valve-2.pdf\">valve<\/a><a href=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2026\/08\/valve-2.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-68d9b3a4-ce01-4e48-8c23-d5c274668dfe\">\ub2e4\uc6b4\ub85c\ub4dc<\/a><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code>{\n  \"topic_id\": \"control_valve_cavitation_flashing_vena_contracta_choked_flow_selection\",\n  \"title\": \"Control Valve Handbook 5.14 Cavitation and Flashing\",\n  \"language\": \"ko\",\n  \"document_purpose\": &#91;\n    \"\uc0b0\uc5c5\uacc4\uce21\uc81c\uc5b4\uae30\uc220\uc0ac \ub2f5\uc548 \uc791\uc131\",\n    \"\uc81c\uc5b4\ubc38\ube0c \uc561\uccb4 \uc11c\ube44\uc2a4 \uc120\uc815\",\n    \"Cavitation\uacfc Flashing\uc758 \ud310\ubcc4\",\n    \"\uc190\uc0c1 \ud615\ud0dc\uc640 \ub300\ucc45\uc758 \uad6c\uc870\ud654\"\n  ],\n  \"source_scope\": {\n    \"primary_source\": \"Emerson Control Valve Handbook, Sixth Edition\",\n    \"chapter\": 5,\n    \"sections\": &#91;\n      \"5.14 Cavitation and Flashing\",\n      \"5.14.1 Choked Flow Causes Flashing and Cavitation\",\n      \"5.14.2 Valve Selection for Flashing Service\",\n      \"5.14.3 Valve Selection for Cavitation Service\"\n    ]\n  },\n  \"symbols\": {\n    \"P1\": {\n      \"meaning\": \"\ubc38\ube0c \uc785\uad6c\uc555\ub825\",\n      \"location\": \"valve inlet\"\n    },\n    \"Pvc\": {\n      \"meaning\": \"Vena Contracta\uc758 \uc555\ub825\",\n      \"location\": \"minimum flow-area region immediately downstream of the restriction\"\n    },\n    \"P2\": {\n      \"meaning\": \"\ubc38\ube0c \ucd9c\uad6c\uc555\ub825\",\n      \"location\": \"valve outlet\"\n    },\n    \"Pv\": {\n      \"meaning\": \"\uc6b4\uc804\uc628\ub3c4\uc5d0\uc11c \uc561\uccb4\uc758 \uc99d\uae30\uc555\",\n      \"dependency\": &#91;\n        \"fluid type\",\n        \"operating temperature\"\n      ]\n    },\n    \"deltaP_actual\": {\n      \"meaning\": \"\ubc38\ube0c \uc591\ub2e8\uc758 \uc2e4\uc81c \uc555\ub825\uac15\ud558\",\n      \"equation\": \"deltaP_actual = P1 - P2\"\n    },\n    \"deltaP_choked\": {\n      \"meaning\": \"IEC \uc561\uccb4 \uc0ac\uc774\uc9d5\uc73c\ub85c \uacc4\uc0b0\ud558\ub294 \ucd08\ud06c \uc555\ub825\uac15\ud558\"\n    }\n  },\n  \"core_mechanism\": &#91;\n    {\n      \"sequence\": 1,\n      \"event\": \"\uc561\uccb4\uac00 \ubc38\ube0c \uc81c\ud55c\ubd80\ub97c \ud1b5\uacfc\ud55c\ub2e4.\"\n    },\n    {\n      \"sequence\": 2,\n      \"event\": \"\uc720\uccb4 \ud750\ub984\uc758 \ub2e8\uba74\uc801\uc774 \uac10\uc18c\ud55c\ub2e4.\"\n    },\n    {\n      \"sequence\": 3,\n      \"event\": \"Vena Contracta\uc5d0\uc11c \uc720\uc18d\uc774 \ucd5c\ub300\uac00 \ub41c\ub2e4.\"\n    },\n    {\n      \"sequence\": 4,\n      \"event\": \"\uc6b4\ub3d9\uc5d0\ub108\uc9c0 \uc99d\uac00\uc5d0 \ub530\ub77c \uc815\uc555\uc774 \ucd5c\uc18c\uac00 \ub41c\ub2e4.\"\n    },\n    {\n      \"sequence\": 5,\n      \"event\": \"Pvc\uac00 Pv\ubcf4\ub2e4 \ub0ae\uc544\uc9c0\uba74 \uc99d\uae30 \uae30\ud3ec\uac00 \uc0dd\uc131\ub41c\ub2e4.\"\n    },\n    {\n      \"sequence\": 6,\n      \"event\": \"\ud558\ub958 \uc555\ub825\ud68c\ubcf5 \ud6c4 \uae30\ud3ec\uac00 \ubd95\uad34\ud558\ub294\uc9c0 \uc720\uc9c0\ub418\ub294\uc9c0\uc5d0 \ub530\ub77c Cavitation\uacfc Flashing\uc744 \uad6c\ubd84\ud55c\ub2e4.\"\n    }\n  ],\n  \"choked_flow_relation\": {\n    \"warning_condition\": \"deltaP_actual &gt; deltaP_choked\",\n    \"meaning\": \"Cavitation \ub610\ub294 Flashing\uc774 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\",\n    \"possible_consequence\": &#91;\n      \"control valve structural damage\",\n      \"trim damage\",\n      \"adjacent downstream piping damage\"\n    ],\n    \"important_note\": \"Choked flow, Cavitation \ubc0f Flashing\uc740 \uad00\ub828\ub418\uc5b4 \uc788\uc73c\ub098 \ub3d9\uc77c\ud55c \uc6a9\uc5b4\uac00 \uc544\ub2c8\ub2e4.\"\n  },\n  \"bubble_formation\": {\n    \"condition\": \"Pvc &lt; Pv\",\n    \"result\": \"liquid vapor bubbles form\",\n    \"shared_stage\": \"\uc774 \ub2e8\uacc4\uae4c\uc9c0\ub294 Cavitation\uacfc Flashing\uc774 \ub3d9\uc77c\ud558\ub2e4.\"\n  },\n  \"decision_logic\": {\n    \"no_vapor_bubble\": {\n      \"condition\": \"Pvc &gt;= Pv\",\n      \"classification\": \"no vapor bubble formation\"\n    },\n    \"cavitation\": {\n      \"condition\": \"Pvc &lt; Pv and P2 &gt; Pv\",\n      \"compact_equation\": \"Pvc &lt; Pv &lt; P2\",\n      \"bubble_behavior\": \"\uc99d\uae30 \uae30\ud3ec\uac00 \ud558\ub958 \uc555\ub825\ud68c\ubcf5 \uad6c\uac04\uc5d0\uc11c \ubd95\uad34\ud55c\ub2e4.\"\n    },\n    \"flashing\": {\n      \"condition\": \"Pvc &lt; Pv and P2 &lt; Pv\",\n      \"compact_equation\": \"Pvc &lt; Pv, P2 &lt; Pv\",\n      \"bubble_behavior\": \"\uc99d\uae30 \uae30\ud3ec\uac00 \ubd95\uad34\ud558\uc9c0 \uc54a\uace0 \ud558\ub958\ub85c \uc9c0\uc18d\ub41c\ub2e4.\"\n    }\n  },\n  \"cavitation\": {\n    \"definition\": \"Vena Contracta\uc5d0\uc11c \ubc1c\uc0dd\ud55c \uc99d\uae30 \uae30\ud3ec\uac00 \ud558\ub958\uc758 \uc555\ub825\ud68c\ubcf5 \uad6c\uac04\uc5d0\uc11c \ubd95\uad34\ud558\ub294 \ud604\uc0c1\",\n    \"pressure_condition\": \"Pvc &lt; Pv &lt; P2\",\n    \"damage_mechanism\": \"\uae30\ud3ec \ubd95\uad34 \uc2dc \ubc29\ucd9c\ub418\ub294 \uc5d0\ub108\uc9c0\uac00 \ubc38\ube0c\uc758 \uace0\uccb4 \ud45c\uba74\uc5d0\uc11c \uc7ac\ub8cc\ub97c \uad6d\ubd80\uc801\uc73c\ub85c \uc81c\uac70\ud55c\ub2e4.\",\n    \"damage_appearance\": \"rough and cinder-like surface\",\n    \"noise_signature\": \"gravel flowing through the valve\uc640 \uc720\uc0ac\ud55c \uc18c\uc74c\",\n    \"damage_locations\": &#91;\n      \"valve trim\",\n      \"valve body\",\n      \"adjacent downstream piping where pressure recovery and bubble collapse occur\"\n    ],\n    \"recovery_relation\": {\n      \"high_recovery_valve\": \"Vena Contracta \uc555\ub825\uc774 \ub354 \ub0ae\uc544\uc9c8 \uc218 \uc788\uc5b4 Cavitation\uc5d0 \ub354 \ucde8\uc57d\ud558\ub2e4.\",\n      \"low_recovery_valve\": \"\ub0b4\ubd80 \ub09c\ub958\uc640 \uc5d0\ub108\uc9c0 \uc18c\uc0b0\uc774 \ucee4 \uc555\ub825\ud68c\ubcf5\ub7c9\uc774 \uc0c1\ub300\uc801\uc73c\ub85c \uc791\ub2e4.\"\n    },\n    \"treatment_methods\": &#91;\n      {\n        \"method\": \"eliminate cavitation\",\n        \"principle\": \"\uc804\uccb4 \uc555\ub825\uac15\ud558\ub97c \ub2e4\ub2e8 \ud2b8\ub9bc\uc73c\ub85c \uc5ec\ub7ec \ub2e8\uacc4\uc5d0 \ubd84\ud560\ud55c\ub2e4.\",\n        \"design_condition\": \"Pvc_i &gt; Pv for every stage\",\n        \"result\": \"\uc99d\uae30 \uae30\ud3ec\uac00 \uc0dd\uc131\ub418\uc9c0 \uc54a\uc73c\ubbc0\ub85c Cavitation\uc774 \ubc1c\uc0dd\ud558\uc9c0 \uc54a\ub294\ub2e4.\"\n      },\n      {\n        \"method\": \"minimize or isolate damage\",\n        \"principle\": \"Cavitation\uc744 \ubc38\ube0c \ud45c\uba74\uc5d0\uc11c \uaca9\ub9ac\ud558\uace0 \uc601\ud5a5\uc744 \ubc1b\ub294 \ud45c\uba74\uc744 \uacbd\ud654\ud55c\ub2e4.\",\n        \"result\": \"Cavitation \uc790\uccb4\ub97c \ubc18\ub4dc\uc2dc \uc81c\uac70\ud558\uc9c0\ub294 \uc54a\uc9c0\ub9cc \uc190\uc0c1\uc744 \uc904\uc778\ub2e4.\"\n      },\n      {\n        \"method\": \"change system conditions\",\n        \"principle\": \"P2\ub97c \ub192\uc5ec Vena Contracta \uc555\ub825\uc774 Pv \uc774\ud558\ub85c \ub0b4\ub824\uac00\uc9c0 \uc54a\uac8c \ud55c\ub2e4.\",\n        \"examples\": &#91;\n          \"\ubc38\ube0c\ub97c \ub354 \ud070 \ud558\ub958 \uc815\uc555\uc218\ub450\uac00 \uc874\uc7ac\ud558\ub294 \uc704\uce58\ub85c \uc774\ub3d9\",\n          \"orifice plate \uc801\uc6a9\",\n          \"backpressure device \uc801\uc6a9\"\n        ],\n        \"caution\": \"Cavitation\uc774 \ubc38\ube0c\uc5d0\uc11c \uc624\ub9ac\ud53c\uc2a4 \ub610\ub294 \ud558\ub958 \uc81c\ud55c\uc7a5\uce58\ub85c \uc774\ub3d9\ud560 \uc218 \uc788\ub2e4.\"\n      }\n    ]\n  },\n  \"flashing\": {\n    \"definition\": \"Vena Contracta\uc5d0\uc11c \ubc1c\uc0dd\ud55c \uc99d\uae30 \uae30\ud3ec\uac00 \ubc38\ube0c \ucd9c\uad6c \uc774\ud6c4\uc5d0\ub3c4 \ubd95\uad34\ud558\uc9c0 \uc54a\uace0 \uc720\uc9c0\ub418\ub294 \ud604\uc0c1\",\n    \"pressure_condition\": \"Pvc &lt; Pv and P2 &lt; Pv\",\n    \"downstream_state\": \"liquid-vapor two-phase flow\",\n    \"damage_mechanism\": \"\uace0\uc18d \uc561\uc801\uacfc 2\uc0c1 \uc720\ub3d9\uc774 \ubc38\ube0c \ud45c\uba74\uc5d0 \ucda9\ub3cc\ud558\uc5ec \uce68\uc2dd\uc744 \ubc1c\uc0dd\uc2dc\ud0a8\ub2e4.\",\n    \"damage_appearance\": \"smooth and polished erosion\",\n    \"primary_damage_location\": \"highest velocity region, commonly at or near the plug and seat-ring seat line\",\n    \"preventability\": {\n      \"can_control_valve_prevent_flashing\": false,\n      \"reason\": &#91;\n        \"P2\ub294 \ud558\ub958 \uacf5\uc815\uacfc \ubc30\uad00\uc5d0 \uc758\ud574 \uacb0\uc815\ub41c\ub2e4.\",\n        \"Pv\ub294 \uc720\uccb4\uc640 \uc6b4\uc804\uc628\ub3c4\uc5d0 \uc758\ud574 \uacb0\uc815\ub41c\ub2e4.\",\n        \"\ub450 \ubcc0\uc218\ub294 \uc81c\uc5b4\ubc38\ube0c\uac00 \uc9c1\uc811 \uc81c\uc5b4\ud558\uc9c0 \uc54a\ub294\ub2e4.\"\n      ]\n    },\n    \"selection_principles\": &#91;\n      {\n        \"principle\": \"reduce particle impact\",\n        \"description\": \"\uc561\uc801\uc774 \ubc38\ube0c \ud45c\uba74\uc5d0 \ucda9\ub3cc\ud558\ub294 \ud69f\uc218\ub97c \uc904\uc778\ub2e4.\"\n      },\n      {\n        \"principle\": \"use hard materials\",\n        \"description\": \"\uc561\uc801 \ucda9\ub3cc\uc774 \ubd88\uac00\ud53c\ud55c \ud45c\uba74\uc5d0 \uac00\ub2a5\ud55c \ud55c \ub2e8\ub2e8\ud55c \uc7ac\ub8cc\ub97c \uc801\uc6a9\ud55c\ub2e4.\"\n      },\n      {\n        \"principle\": \"reduce erosive velocity\",\n        \"description\": \"\uc2a4\ub85c\ud2c0\ub9c1 \uc9c0\uc810 \ud558\ub958\uc758 \uc720\ub85c \uba74\uc801\uc744 \ud655\ub300\ud558\uc5ec 2\uc0c1 \uc720\ub3d9 \uc18d\ub3c4\ub97c \ub0ae\ucd98\ub2e4.\"\n      },\n      {\n        \"principle\": \"reduce flow-direction changes\",\n        \"description\": \"\uc720\ub3d9 \ubc29\ud5a5 \ubcc0\ud654\uac00 \uc801\uc740 \ubc38\ube0c \ud615\uc0c1\uc744 \uc120\uc815\ud55c\ub2e4.\"\n      }\n    ],\n    \"recommended_valve_geometries\": &#91;\n      \"sliding-stem angle valve\",\n      \"eccentric rotary plug valve\",\n      \"segmented ball valve\",\n      \"valve with expanded downstream flow area\"\n    ],\n    \"corrosion_erosion_synergy\": {\n      \"description\": \"\ubd80\uc2dd\uacfc Flashing \uce68\uc2dd\uc774 \ud568\uaed8 \ubc1c\uc0dd\ud558\uba74 \uac01\uac01\uc758 \ub2e8\ub3c5 \uc190\uc0c1\ubcf4\ub2e4 \ub354 \uc2ec\ud55c \uc190\uc0c1\uc774 \ubc1c\uc0dd\ud560 \uc218 \uc788\ub2e4.\",\n      \"handbook_example\": \"\ubb3c\uacfc \ud0c4\uc18c\uac15 \ubc38\ube0c\uc5d0\uc11c \ubd80\uc2dd\uc73c\ub85c \ud615\uc131\ub41c \uc5f0\ud55c \uc0b0\ud654\uce35\uc744 Flashing \uc720\ub3d9\uc774 \ubc18\ubcf5\uc801\uc73c\ub85c \uc81c\uac70\ud55c\ub2e4.\",\n      \"response\": \"\ubd80\uc2dd \uc5b5\uc81c\ub97c \uace0\ub824\ud55c \ubc38\ube0c \ubc14\ub514 \ubc0f \ud2b8\ub9bc \uc7ac\uc9c8\uc744 \uc120\uc815\ud55c\ub2e4.\"\n    }\n  },\n  \"comparison\": &#91;\n    {\n      \"attribute\": \"bubble generation\",\n      \"cavitation\": \"Pvc &lt; Pv\",\n      \"flashing\": \"Pvc &lt; Pv\"\n    },\n    {\n      \"attribute\": \"outlet pressure\",\n      \"cavitation\": \"P2 &gt; Pv\",\n      \"flashing\": \"P2 &lt; Pv\"\n    },\n    {\n      \"attribute\": \"bubble behavior\",\n      \"cavitation\": \"collapse after pressure recovery\",\n      \"flashing\": \"remain in downstream flow\"\n    },\n    {\n      \"attribute\": \"damage mechanism\",\n      \"cavitation\": \"bubble-collapse energy\",\n      \"flashing\": \"high-velocity two-phase erosion\"\n    },\n    {\n      \"attribute\": \"damage appearance\",\n      \"cavitation\": \"rough and cinder-like\",\n      \"flashing\": \"smooth and polished\"\n    },\n    {\n      \"attribute\": \"fundamental prevention by valve\",\n      \"cavitation\": \"possible by pressure-drop management\",\n      \"flashing\": \"not possible by the valve alone\"\n    }\n  ],\n  \"selection_workflow\": &#91;\n    \"P1, P2, operating temperature \ubc0f Pv\ub97c \ud655\uc778\ud55c\ub2e4.\",\n    \"deltaP_actual = P1 - P2\ub97c \uacc4\uc0b0\ud55c\ub2e4.\",\n    \"IEC \uc561\uccb4 \uc0ac\uc774\uc9d5\uc73c\ub85c deltaP_choked\ub97c \uacc4\uc0b0\ud55c\ub2e4.\",\n    \"deltaP_actual &gt; deltaP_choked\uc774\uba74 \ucd08\ud06c \uc720\ub3d9\uacfc \uc0c1\ubcc0\ud654 \uac00\ub2a5\uc131\uc744 \uac80\ud1a0\ud55c\ub2e4.\",\n    \"Pvc &lt; Pv\uc778\uc9c0 \ud655\uc778\ud558\uc5ec \uae30\ud3ec \uc0dd\uc131 \uc5ec\ubd80\ub97c \ud310\ub2e8\ud55c\ub2e4.\",\n    \"P2 &gt; Pv\uc774\uba74 Cavitation\uc73c\ub85c \ubd84\ub958\ud55c\ub2e4.\",\n    \"P2 &lt; Pv\uc774\uba74 Flashing\uc73c\ub85c \ubd84\ub958\ud55c\ub2e4.\",\n    \"Cavitation\uc774\uba74 \ub2e4\ub2e8 \uac10\uc555, \uc190\uc0c1 \uaca9\ub9ac \ub610\ub294 P2 \uc0c1\uc2b9\uc744 \uac80\ud1a0\ud55c\ub2e4.\",\n    \"Flashing\uc774\uba74 \uc9c1\uc120\ud615 \uc720\ub85c, \ud655\ub300\ub41c \ud558\ub958 \uc720\ub85c, \uc18d\ub3c4 \uc800\uac10 \ubc0f \uacbd\uc9c8\uc7ac\ub8cc\ub97c \uc801\uc6a9\ud55c\ub2e4.\",\n    \"\ubc38\ube0c \ud2b8\ub9bc, \ubc14\ub514 \ubc0f \uc778\uc811 \ud558\ub958 \ubc30\uad00\uc758 \uc190\uc0c1 \uac00\ub2a5\uc131\uc744 \uac80\ud1a0\ud55c\ub2e4.\",\n    \"\ubd80\uc2dd\uacfc \uce68\uc2dd\uc758 \ubcf5\ud569\uc791\uc6a9\uc744 \uace0\ub824\ud558\uc5ec \uc7ac\uc9c8\uc744 \uc120\uc815\ud55c\ub2e4.\"\n  ],\n  \"common_misconceptions\": &#91;\n    {\n      \"incorrect\": \"Cavitation\uacfc Flashing\uc740 \uae30\ud3ec\uac00 \ubc1c\uc0dd\ud558\ub294 \uc21c\uac04\ubd80\ud130 \uc11c\ub85c \ub2e4\ub978 \ud604\uc0c1\uc774\ub2e4.\",\n      \"correct\": \"\ub450 \ud604\uc0c1 \ubaa8\ub450 Pvc &lt; Pv\uc5d0\uc11c \uae30\ud3ec\uac00 \ubc1c\uc0dd\ud558\uba70, \ud558\ub958 \uc555\ub825\ud68c\ubcf5 \ud6c4 \uae30\ud3ec \uac70\ub3d9\uc73c\ub85c \uad6c\ubd84\ud55c\ub2e4.\"\n    },\n    {\n      \"incorrect\": \"P2\uac00 Pv\ubcf4\ub2e4 \ub0ae\uc73c\uba74 Cavitation\uc774 \ubc1c\uc0dd\ud55c\ub2e4.\",\n      \"correct\": \"P2 &lt; Pv\uc774\uba74 \uae30\ud3ec\uac00 \ubd95\uad34\ud558\uc9c0 \uc54a\uc73c\ubbc0\ub85c Flashing\uc774\ub2e4.\"\n    },\n    {\n      \"incorrect\": \"Anti-cavitation trim\uc73c\ub85c Flashing\uc744 \uc81c\uac70\ud560 \uc218 \uc788\ub2e4.\",\n      \"correct\": \"Flashing\uc740 P2\uc640 Pv\uac00 \uacb0\uc815\ud558\ub294 \uacf5\uc815\ud604\uc0c1\uc774\ubbc0\ub85c \ubc38\ube0c \uc790\uccb4\ub85c \uc81c\uac70\ud560 \uc218 \uc5c6\ub2e4.\"\n    },\n    {\n      \"incorrect\": \"High-recovery valve\ub294 \ubaa8\ub4e0 \uc561\uccb4 \uace0\uc555\uac15\ud558 \uc11c\ube44\uc2a4\uc5d0 \uc720\ub9ac\ud558\ub2e4.\",\n      \"correct\": \"High-recovery valve\ub294 Vena Contracta \uc555\ub825\uc774 \ub354 \ub0ae\uc544\uc838 Cavitation\uc5d0 \ucde8\uc57d\ud560 \uc218 \uc788\ub2e4.\"\n    },\n    {\n      \"incorrect\": \"Backpressure device\ub294 Cavitation\uc744 \uc2dc\uc2a4\ud15c \uc804\uccb4\uc5d0\uc11c \ubc18\ub4dc\uc2dc \uc81c\uac70\ud55c\ub2e4.\",\n      \"correct\": \"Cavitation \uc704\uce58\uac00 \ud558\ub958 \uc81c\ud55c\uc7a5\uce58\ub85c \uc774\ub3d9\ud560 \uc218 \uc788\uc73c\ubbc0\ub85c \uc804\uccb4 \uc2dc\uc2a4\ud15c\uc744 \uac80\ud1a0\ud574\uc57c \ud55c\ub2e4.\"\n    }\n  ],\n  \"exam_core_answer\": {\n    \"definition\": \"\uc81c\uc5b4\ubc38\ube0c \uc81c\ud55c\ubd80\ub97c \ud1b5\uacfc\ud55c \uc561\uccb4\ub294 Vena Contracta\uc5d0\uc11c \uc720\uc18d\uc774 \ucd5c\ub300\uac00 \ub418\uace0 \uc555\ub825\uc774 \ucd5c\uc18c\uac00 \ub41c\ub2e4. Pvc\uac00 Pv\ubcf4\ub2e4 \ub0ae\uc544\uc9c0\uba74 \uc99d\uae30 \uae30\ud3ec\uac00 \ubc1c\uc0dd\ud55c\ub2e4.\",\n    \"cavitation_statement\": \"Pvc &lt; Pv &lt; P2\uc774\uba74 \ud558\ub958 \uc555\ub825\ud68c\ubcf5 \uacfc\uc815\uc5d0\uc11c \uae30\ud3ec\uac00 \ubd95\uad34\ud558\uc5ec Cavitation\uc774 \ubc1c\uc0dd\ud55c\ub2e4.\",\n    \"flashing_statement\": \"Pvc &lt; Pv\uc774\uace0 P2 &lt; Pv\uc774\uba74 \uae30\ud3ec\uac00 \ud558\ub958\uae4c\uc9c0 \uc720\uc9c0\ub418\uc5b4 Flashing\uc774 \ubc1c\uc0dd\ud55c\ub2e4.\",\n    \"cavitation_countermeasure\": \"\uc804\uccb4 \uc555\ub825\uac15\ud558\ub97c \ub2e4\ub2e8 \ud2b8\ub9bc\uc73c\ub85c \ubd84\ud560\ud558\uc5ec \uac01 \ub2e8\uacc4\uc758 \ucd5c\uc800\uc555\ub825\uc744 Pv \uc774\uc0c1\uc73c\ub85c \uc720\uc9c0\ud55c\ub2e4.\",\n    \"flashing_countermeasure\": \"\uc9c1\uc120 \uc720\ub85c, \ud655\ub300\ub41c \ud558\ub958 \uc720\ub85c, \uc18d\ub3c4 \uc800\uac10 \ubc0f \uacbd\uc9c8\uc7ac\ub8cc\ub85c \uce68\uc2dd \uc190\uc0c1\uc744 \ucd5c\uc18c\ud654\ud55c\ub2e4.\"\n  },\n  \"keytags\": &#91;\n    \"Cavitation\",\n    \"Flashing\",\n    \"Vena Contracta\",\n    \"Choked Flow\",\n    \"Multi-stage Trim\"\n  ]\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\uc81c\uc5b4\ubc38\ube0c \ud578\ub4dc\ubd81 5.14\uc5d0\uc11c\ub294 Cavitation\uacfc Flashing\uc758 \uac1c\ub150, \ubc1c\uc0dd \uc870\uac74 \ubc0f \uc190\uc0c1 \uba54\ucee4\ub2c8\uc998\uc744 \uc124\uba85\ud558\uace0 \uc788\uc2b5\ub2c8\ub2e4. \ub450 \ud604\uc0c1\uc740 \ubaa8\ub450 Pvc < Pv\uc5d0\uc11c \uae30\ud3ec\uac00 \ubc1c\uc0dd\ud558\uc9c0\ub9cc, \ud558\ub958 \uc555\ub825 \ud68c\ubcf5 \ud6c4 \uae30\ud3ec \uac70\ub3d9\uc5d0 \ub530\ub77c Cavitation \ub610\ub294 Flashing\uc73c\ub85c \uad6c\ubd84\ub429\ub2c8\ub2e4. \uc801\uc808\ud55c \uc120\ud0dd \ubc0f \ub300\ucc45\uc774 \ud544\uc694\ud569\ub2c8\ub2e4.\n<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1185],"tags":[1353,1614,2068],"class_list":["post-9321","post","type-post","status-publish","format-standard","hentry","category-1185","tag-cavitation","tag-flashing","tag-multi-stage-trim"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9321","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/comments?post=9321"}],"version-history":[{"count":4,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9321\/revisions"}],"predecessor-version":[{"id":9348,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/9321\/revisions\/9348"}],"wp:attachment":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/media?parent=9321"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/categories?post=9321"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/tags?post=9321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}