{"id":14825,"date":"2026-03-17T14:27:59","date_gmt":"2026-03-17T06:27:59","guid":{"rendered":"https:\/\/www.xintaivalves.com\/?page_id=14825"},"modified":"2026-03-17T15:20:53","modified_gmt":"2026-03-17T07:20:53","slug":"valve-cv-calculator-flow-coefficient-for-valve-sizing","status":"publish","type":"page","link":"https:\/\/www.xintaivalves.com\/ar\/valve-cv-calculator-flow-coefficient-for-valve-sizing\/","title":{"rendered":"\u062d\u0627\u0633\u0628\u0629 \u0645\u0639\u0627\u0645\u0644 \u0627\u0644\u062a\u062f\u0641\u0642 \u0644\u0644\u0635\u0645\u0627\u0645\u0627\u062a - \u0645\u0639\u0627\u0645\u0644 \u0627\u0644\u062a\u062f\u0641\u0642 \u0644\u062a\u062d\u062f\u064a\u062f \u062d\u062c\u0645 \u0627\u0644\u0635\u0645\u0627\u0645\u0627\u062a"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"14825\" class=\"elementor elementor-14825\" 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 XINTAI VALVE CV CALCULATOR \u2014 FULL PAGE\r\n   Designed for Elementor Custom HTML embed\r\n   \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 *\/\r\n\r\n:root {\r\n  \/* \u2500\u2500 Xintai Brand Colors \u2500\u2500 *\/\r\n  --navy: #1A1A1A;\r\n  --navy-mid: #2A2A2A;\r\n  --navy-light: #3A3A3A;\r\n  --accent: #C8102E;\r\n  --accent-hover: #E01535;\r\n  --accent-glow: rgba(200, 16, 46, 0.10);\r\n  --steel: #999999;\r\n  --steel-light: #CCCCCC;\r\n  --bg: #F5F5F5;\r\n  --bg-card: #FFFFFF;\r\n  --text: #1A1A1A;\r\n  --text-secondary: #555555;\r\n  --text-muted: #888888;\r\n  --border: #E0E0E0;\r\n  --success: #2ECC71;\r\n  --error: #C8102E;\r\n  --warning: #F39C12;\r\n  --radius: 8px;\r\n  --radius-lg: 12px;\r\n  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);\r\n  --shadow-md: 0 4px 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padding: 12px 6px; }\r\n\r\n  .xv-calc-actions { padding: 20px 16px; flex-direction: column; gap: 12px; }\r\n  .xv-btn-calc, .xv-btn-reset { width: 100%; text-align: center; box-sizing: border-box; }\r\n\r\n  .xv-result-box { margin: 16px; padding: 20px 16px; width: auto; }\r\n  .xv-result-detail { grid-template-columns: 1fr; gap: 10px; }\r\n  \r\n  .xv-content-section { padding: 40px 16px; }\r\n  h1.xv-h1 { font-size: 28px; }\r\n}\r\n\r\n.xv-field label {\r\n  display: block;\r\n  font-size: 13px;\r\n  font-weight: 600;\r\n  color: var(--text-secondary);\r\n  margin-bottom: 6px;\r\n  letter-spacing: 0.3px;\r\n}\r\n.xv-input-wrap {\r\n  display: flex;\r\n  border: 1.5px solid var(--border);\r\n  border-radius: 8px;\r\n  overflow: hidden;\r\n  transition: border-color 0.2s;\r\n}\r\n.xv-input-wrap:focus-within {\r\n  border-color: var(--accent);\r\n  box-shadow: 0 0 0 3px var(--accent-glow);\r\n}\r\n.xv-input-wrap input {\r\n  flex: 1;\r\n  padding: 12px 14px;\r\n  font-size: 15px;\r\n  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1.5px solid var(--border);\r\n  border-radius: 8px;\r\n  cursor: pointer;\r\n  transition: all 0.2s;\r\n}\r\n.xv-btn-reset:hover { border-color: var(--text-muted); color: var(--text-secondary); }\r\n\r\n\/* Result *\/\r\n.xv-result-box {\r\n  margin: 24px 36px 32px;\r\n  padding: 28px 32px;\r\n  border-radius: var(--radius);\r\n  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 100%);\r\n  color: white;\r\n  display: none;\r\n}\r\n.xv-result-box.show { display: block; animation: fadeUp 0.4s ease; }\r\n@keyframes fadeUp { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }\r\n\r\n.xv-result-label {\r\n  font-size: 12px;\r\n  text-transform: uppercase;\r\n  letter-spacing: 1.5px;\r\n  color: var(--steel);\r\n  margin-bottom: 8px;\r\n  font-weight: 600;\r\n}\r\n.xv-result-value {\r\n  font-family: 'JetBrains Mono', monospace;\r\n  font-size: 40px;\r\n  font-weight: 700;\r\n  color: #FFFFFF;\r\n  line-height: 1;\r\n  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\u2500\u2500\u2500 Cv\/Kv CONVERSION MINI-TOOL \u2500\u2500\u2500 *\/\r\n.xv-converter-section {\r\n  padding: 40px 24px 60px;\r\n}\r\n.xv-converter-card {\r\n  max-width: 600px;\r\n  margin: 0 auto;\r\n  background: var(--bg-card);\r\n  border-radius: var(--radius-lg);\r\n  box-shadow: var(--shadow-md);\r\n  border: 1px solid var(--border);\r\n  overflow: hidden;\r\n}\r\n.xv-converter-header {\r\n  padding: 20px 28px;\r\n  background: var(--bg);\r\n  border-bottom: 1px solid var(--border);\r\n}\r\n.xv-converter-header h3 {\r\n  font-family: 'Playfair Display', serif;\r\n  font-size: 18px;\r\n  font-weight: 400;\r\n}\r\n.xv-converter-body {\r\n  padding: 28px;\r\n  display: flex;\r\n  gap: 16px;\r\n  align-items: end;\r\n  flex-wrap: wrap;\r\n}\r\n.xv-converter-body .xv-field { flex: 1; min-width: 140px; }\r\n.xv-convert-arrow {\r\n  width: 40px;\r\n  height: 40px;\r\n  border-radius: 50%;\r\n  background: var(--accent-glow);\r\n  display: flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  flex-shrink: 0;\r\n  color: var(--accent);\r\n  font-weight: 700;\r\n  margin-bottom: 2px;\r\n}\r\n\r\n\/* \u2500\u2500\u2500 SEO CONTENT SECTIONS \u2500\u2500\u2500 *\/\r\n.xv-content-section {\r\n  padding: 60px 24px;\r\n}\r\n.xv-content-section:nth-child(even) {\r\n  background: var(--bg-card);\r\n}\r\n.xv-content-inner {\r\n  max-width: 820px;\r\n  margin: 0 auto;\r\n}\r\n.xv-content-inner h2 {\r\n  font-family: 'Playfair Display', serif;\r\n  font-size: clamp(26px, 4vw, 36px);\r\n  color: var(--navy);\r\n  margin-bottom: 20px;\r\n  line-height: 1.25;\r\n}\r\n.xv-content-inner h3 {\r\n  font-family: 'Playfair Display', serif;\r\n  font-size: 22px;\r\n  color: var(--navy);\r\n  margin: 32px 0 12px;\r\n}\r\n.xv-content-inner p {\r\n  font-size: 16px;\r\n  color: var(--text-secondary);\r\n  margin-bottom: 16px;\r\n  line-height: 1.8;\r\n}\r\n.xv-content-inner strong { color: var(--text); }\r\n\r\n\/* Formula box *\/\r\n.xv-formula-box {\r\n  background: var(--navy);\r\n  color: white;\r\n  padding: 28px 32px;\r\n  border-radius: var(--radius);\r\n  margin: 24px 0;\r\n  text-align: center;\r\n}\r\n.xv-formula-box .formula {\r\n  font-family: 'JetBrains Mono', monospace;\r\n  font-size: clamp(18px, 3vw, 26px);\r\n  color: #FFFFFF;\r\n  margin-bottom: 12px;\r\n}\r\n.xv-formula-box .formula-desc {\r\n  font-size: 13px;\r\n  color: var(--steel);\r\n  line-height: 1.6;\r\n}\r\n.xv-formula-box .formula-desc span {\r\n  display: inline-block;\r\n  margin: 0 6px;\r\n  padding: 2px 8px;\r\n  background: rgba(255,255,255,0.08);\r\n  border-radius: 4px;\r\n  font-family: 'JetBrains Mono', monospace;\r\n  font-size: 12px;\r\n  color: var(--steel-light);\r\n}\r\n\r\n\/* Reference table *\/\r\n.xv-table-wrap {\r\n  overflow-x: auto;\r\n  margin: 24px 0;\r\n  border-radius: var(--radius);\r\n  border: 1px solid var(--border);\r\n}\r\n.xv-table {\r\n  width: 100%;\r\n  border-collapse: collapse;\r\n  font-size: 14px;\r\n}\r\n.xv-table thead { background: var(--navy); color: white; }\r\n.xv-table th {\r\n  padding: 14px 18px;\r\n  text-align: left;\r\n  font-weight: 600;\r\n  font-size: 13px;\r\n  letter-spacing: 0.5px;\r\n  white-space: nowrap;\r\n}\r\n.xv-table td {\r\n  padding: 12px 18px;\r\n  border-bottom: 1px solid var(--border);\r\n  color: var(--text-secondary);\r\n}\r\n.xv-table tbody tr:last-child td { border-bottom: none; }\r\n.xv-table tbody tr:nth-child(even) { background: var(--bg); }\r\n.xv-table tbody tr:hover { background: var(--accent-glow); }\r\n.xv-table .mono {\r\n  font-family: 'JetBrains Mono', monospace;\r\n  font-weight: 500;\r\n  color: var(--text);\r\n}\r\n\r\n\/* \u2500\u2500\u2500 CTA SECTION \u2500\u2500\u2500 *\/\r\n.xv-cta-section {\r\n  padding: 80px 24px;\r\n  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-mid) 100%);\r\n  color: white;\r\n  text-align: center;\r\n  position: relative;\r\n  overflow: hidden;\r\n}\r\n.xv-cta-section::before {\r\n  content: '';\r\n  position: absolute;\r\n  top: -100px;\r\n  left: 50%;\r\n  transform: translateX(-50%);\r\n  width: 600px;\r\n  height: 600px;\r\n  background: radial-gradient(circle, rgba(200,16,46,0.08) 0%, transparent 60%);\r\n  border-radius: 50%;\r\n}\r\n.xv-cta-inner {\r\n  max-width: 680px;\r\n  margin: 0 auto;\r\n  position: relative;\r\n  z-index: 1;\r\n}\r\n.xv-cta-inner h2 {\r\nfont-family: 'Playfair Display', serif;\r\n  font-size: clamp(32px, 4vw, 44px) !important; \/* \u54cd\u5e94\u5f0f\u5b57\u53f7\uff0c\u968f\u5c4f\u5e55\u5927\u5c0f\u81ea\u52a8\u7f29\u653e *\/\r\n  font-weight: 700 !important;\r\n  color: #FFFFFF !important; \/* \u5f3a\u5236\u5b57\u4f53\u989c\u8272\u4e3a\u767d\u8272 *\/\r\n  margin-bottom: 16px;\r\n}\r\n.xv-cta-inner p {\r\n  font-size: 17px;\r\n  color: var(--steel-light);\r\n  margin-bottom: 32px;\r\n  line-height: 1.7;\r\n}\r\n.xv-btn-cta {\r\n  display: inline-block;\r\n  padding: 16px 44px;\r\n  font-size: 16px;\r\n  font-weight: 700;\r\n  font-family: 'Inter', sans-serif;\r\n  background: var(--accent);\r\n  color: #FFFFFF;\r\n  border: none;\r\n  border-radius: 8px;\r\n  cursor: pointer;\r\n  transition: all 0.2s;\r\n  text-decoration: none;\r\n  letter-spacing: 0.3px;\r\n}\r\n.xv-btn-cta:hover {\r\n  background: var(--accent-hover);\r\n  box-shadow: var(--shadow-glow);\r\n  transform: translateY(-2px);\r\n}\r\n.xv-cta-trust {\r\n  margin-top: 28px;\r\n  display: flex;\r\n  justify-content: center;\r\n  gap: 32px;\r\n  flex-wrap: wrap;\r\n  font-size: 13px;\r\n  color: var(--steel);\r\n}\r\n.xv-cta-trust span {\r\n  display: flex;\r\n  align-items: center;\r\n  gap: 6px;\r\n}\r\n\r\n\/* \u2500\u2500\u2500 FAQ \/ Schema \u2500\u2500\u2500 *\/\r\n.xv-faq-section {\r\n  padding: 60px 24px;\r\n  background: var(--bg-card);\r\n}\r\n.xv-faq-inner {\r\n  max-width: 820px;\r\n  margin: 0 auto;\r\n}\r\n.xv-faq-inner h2 {\r\n  font-family: 'Playfair Display', serif;\r\n  font-size: clamp(26px, 4vw, 36px);\r\n  color: var(--navy);\r\n  margin-bottom: 32px;\r\n  text-align: center;\r\n}\r\n.xv-faq-item {\r\n  border: 1px solid var(--border);\r\n  border-radius: var(--radius);\r\n  margin-bottom: 12px;\r\n  overflow: hidden;\r\n  transition: box-shadow 0.2s;\r\n}\r\n.xv-faq-item:hover { box-shadow: var(--shadow-sm); }\r\n.xv-faq-q {\r\n  padding: 18px 24px;\r\n  font-size: 16px;\r\n  font-weight: 600;\r\n  color: var(--text);\r\n  cursor: pointer;\r\n  display: flex;\r\n  justify-content: space-between;\r\n  align-items: center;\r\n  background: white;\r\n  border: none;\r\n  width: 100%;\r\n  text-align: left;\r\n  font-family: 'Inter', sans-serif;\r\n  line-height: 1.5;\r\n}\r\n.xv-faq-q::after {\r\n  content: '+';\r\n  font-size: 22px;\r\n  color: var(--accent);\r\n  font-weight: 300;\r\n  flex-shrink: 0;\r\n  margin-left: 16px;\r\n  transition: transform 0.2s;\r\n}\r\n.xv-faq-q.open::after { content: '\u2212'; }\r\n.xv-faq-a {\r\n  padding: 0 24px;\r\n  max-height: 0;\r\n  overflow: hidden;\r\n  transition: all 0.3s ease;\r\n}\r\n.xv-faq-a.open {\r\n  padding: 0 24px 20px;\r\n  max-height: 400px;\r\n}\r\n.xv-faq-a p {\r\n  font-size: 15px;\r\n  color: var(--text-secondary);\r\n  line-height: 1.8;\r\n}\r\n\r\n\/* \u2500\u2500\u2500 FOOTER NOTE \u2500\u2500\u2500 *\/\r\n.xv-disclaimer {\r\n  padding: 24px;\r\n  text-align: center;\r\n  font-size: 12px;\r\n  color: var(--text-muted);\r\n  border-top: 1px solid var(--border);\r\n}\r\n<\/style>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b22dcf7 e-con-full e-flex e-con e-parent\" data-id=\"b22dcf7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d261cae elementor-widget__width-inherit elementor-widget elementor-widget-html\" data-id=\"d261cae\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"xv-page\">\r\n\r\n<section class=\"xv-hero\">\r\n  <div class=\"xv-hero-inner\">\r\n    <h1 class=\"xv-h1\">Valve <em>Cv Calculator<\/em> \u2014 Flow Coefficient for Valve Sizing<\/h1>\r\n    <p class=\"xv-hero-desc\">Calculate valve flow coefficient (Cv) or flow rate for liquid and gas applications. Use our free tool to properly size control valves, ball valves, gate valves, and butterfly valves \u2014 then get a quote from our factory.<\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-calc-section\" id=\"calculator\">\r\n  <div class=\"xv-calc-card\">\r\n    <div class=\"xv-calc-header\">\r\n      <div class=\"xv-calc-icon\">\r\n        <svg viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M4 4h16v16H4z\"\/><path d=\"M4 10h16\"\/><path d=\"M10 4v16\"\/><\/svg>\r\n      <\/div>\r\n      <div>\r\n        <h2>Valve Cv \/ Flow Rate Calculator<\/h2>\r\n        <p>For liquid and gas flow \u2014 supports imperial &amp; metric units<\/p>\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-toggle-row\">\r\n      <div>\r\n        <label>Calculate<\/label>\r\n        <div class=\"xv-toggle-group\" id=\"calcTypeGroup\">\r\n          <button class=\"xv-toggle-btn active\" data-value=\"cv\" onclick=\"setCalcType('cv')\">Cv Value<\/button>\r\n          <button class=\"xv-toggle-btn\" data-value=\"flow\" onclick=\"setCalcType('flow')\">Flow Rate<\/button>\r\n        <\/div>\r\n      <\/div>\r\n      <div>\r\n        <label>Medium Type<\/label>\r\n        <div class=\"xv-toggle-group\" id=\"mediumTypeGroup\">\r\n          <button class=\"xv-toggle-btn active\" data-value=\"liquid\" onclick=\"setMediumType('liquid')\">Liquid<\/button>\r\n          <button class=\"xv-toggle-btn\" data-value=\"gas\" onclick=\"setMediumType('gas')\">Gas<\/button>\r\n        <\/div>\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-calc-body\">\r\n      <div class=\"xv-form-grid\">\r\n        <div class=\"xv-field\">\r\n          <label>Inlet Pressure (P\u2081)<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"p1\" placeholder=\"e.g. 100\" step=\"any\">\r\n            <select id=\"p1Unit\">\r\n              <option value=\"psi\">psi<\/option>\r\n              <option value=\"bar\">bar<\/option>\r\n              <option value=\"kpa\">kPa<\/option>\r\n              <option value=\"mpa\">MPa<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\">\r\n          <label>Outlet Pressure (P\u2082)<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"p2\" placeholder=\"e.g. 80\" step=\"any\">\r\n            <select id=\"p2Unit\">\r\n              <option value=\"psi\">psi<\/option>\r\n              <option value=\"bar\">bar<\/option>\r\n              <option value=\"kpa\">kPa<\/option>\r\n              <option value=\"mpa\">MPa<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"flowField\">\r\n          <label>Flow Rate (Q)<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"flowRate\" placeholder=\"e.g. 50\" step=\"any\">\r\n            <select id=\"flowUnit\">\r\n              <option value=\"gpm\">GPM<\/option>\r\n              <option value=\"lpm\">L\/min<\/option>\r\n              <option value=\"m3h\">m\u00b3\/h<\/option>\r\n              <option value=\"scfm\">SCFM<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"cvField\" style=\"display:none;\">\r\n          <label>Known Cv Value<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"cvInput\" placeholder=\"e.g. 12\" step=\"any\">\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"mediumField\">\r\n          <label>System Medium<\/label>\r\n          <div class=\"xv-select-wrap\">\r\n            <select id=\"medium\" onchange=\"updateSG()\">\r\n              <option value=\"1.00\">Water (SG = 1.00)<\/option>\r\n              <option value=\"0.79\">Alcohol, Ethyl (SG = 0.79)<\/option>\r\n              <option value=\"0.79\">Alcohol, Methyl (SG = 0.79)<\/option>\r\n              <option value=\"0.88\">Benzene (SG = 0.88)<\/option>\r\n              <option value=\"0.75\">Gasoline (SG = 0.75)<\/option>\r\n              <option value=\"0.82\">Kerosene (SG = 0.82)<\/option>\r\n              <option value=\"1.03\">Sea Water (SG = 1.03)<\/option>\r\n              <option value=\"custom\">Other \u2014 enter SG manually<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"gasMediumField\" style=\"display:none;\">\r\n          <label>System Medium<\/label>\r\n          <div class=\"xv-select-wrap\">\r\n            <select id=\"gasMedium\" onchange=\"updateGasSG()\">\r\n              <option value=\"1.00\">Air (SG = 1.00)<\/option>\r\n              <option value=\"0.97\">Nitrogen (SG = 0.97)<\/option>\r\n              <option value=\"0.07\">Hydrogen (SG = 0.07)<\/option>\r\n              <option value=\"1.52\">Carbon Dioxide (SG = 1.52)<\/option>\r\n              <option value=\"0.55\">Methane (SG = 0.55)<\/option>\r\n              <option value=\"1.38\">Argon (SG = 1.38)<\/option>\r\n              <option value=\"0.14\">Helium (SG = 0.14)<\/option>\r\n              <option value=\"0.59\">Ammonia (SG = 0.59)<\/option>\r\n              <option value=\"0.91\">Acetylene (SG = 0.91)<\/option>\r\n              <option value=\"2.01\">Butane (SG = 2.01)<\/option>\r\n              <option value=\"custom\">Other \u2014 enter SG manually<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"sgField\" style=\"display:none;\">\r\n          <label>Specific Gravity (relative to water\/air)<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"sgInput\" placeholder=\"e.g. 1.0\" step=\"any\" value=\"1.0\">\r\n          <\/div>\r\n        <\/div>\r\n        <div class=\"xv-field\" id=\"tempField\" style=\"display:none;\">\r\n          <label>Temperature<\/label>\r\n          <div class=\"xv-input-wrap\">\r\n            <input type=\"number\" id=\"temp\" placeholder=\"e.g. 68\" step=\"any\" value=\"68\">\r\n            <select id=\"tempUnit\">\r\n              <option value=\"F\">\u00b0F<\/option>\r\n              <option value=\"C\">\u00b0C<\/option>\r\n            <\/select>\r\n          <\/div>\r\n        <\/div>\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-error-msg\" id=\"errorMsg\"><\/div>\r\n\r\n    <div class=\"xv-calc-actions\">\r\n      <button class=\"xv-btn-calc\" onclick=\"calculate()\">Calculate<\/button>\r\n      <button class=\"xv-btn-reset\" onclick=\"resetCalc()\">Reset<\/button>\r\n    <\/div>\r\n\r\n    <div class=\"xv-result-box\" id=\"resultBox\">\r\n      <div class=\"xv-result-label\" id=\"resultLabel\">CALCULATED Cv VALUE<\/div>\r\n      <div class=\"xv-result-value\" id=\"resultValue\">\u2014<\/div>\r\n      <div class=\"xv-result-unit\" id=\"resultUnit\"><\/div>\r\n      <div class=\"xv-result-detail\" id=\"resultDetail\"><\/div>\r\n    <\/div>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-converter-section\">\r\n  <div class=\"xv-converter-card\">\r\n    <div class=\"xv-converter-header\">\r\n      <h3>Cv \u2194 Kv Quick Converter<\/h3>\r\n    <\/div>\r\n    <div class=\"xv-converter-body\">\r\n      <div class=\"xv-field\">\r\n        <label>Cv Value<\/label>\r\n        <div class=\"xv-input-wrap\">\r\n          <input type=\"number\" id=\"convCv\" placeholder=\"Enter Cv\" step=\"any\" oninput=\"convertCvKv('cv')\">\r\n        <\/div>\r\n      <\/div>\r\n      <div class=\"xv-convert-arrow\">\u21c4<\/div>\r\n      <div class=\"xv-field\">\r\n        <label>Kv Value<\/label>\r\n        <div class=\"xv-input-wrap\">\r\n          <input type=\"number\" id=\"convKv\" placeholder=\"Enter Kv\" step=\"any\" oninput=\"convertCvKv('kv')\">\r\n        <\/div>\r\n      <\/div>\r\n    <\/div>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-content-section\">\r\n  <div class=\"xv-content-inner\">\r\n    <h2>What Is Valve Flow Coefficient (Cv)?<\/h2>\r\n    <p>The <strong>valve flow coefficient (Cv)<\/strong> is a standardized measure of a valve's ability to pass fluid. It represents the volume of water at 60\u00b0F (15.6\u00b0C), in US gallons per minute (GPM), that will flow through a fully open valve when there is a pressure drop of 1 psi across it.<\/p>\r\n    <p>In practical terms, a valve with a Cv of 10 will allow 10 GPM of water to pass through at a 1 psi pressure differential. The higher the Cv value, the greater the valve's flow capacity. Engineers and procurement professionals rely on this coefficient to properly size valves in industrial piping systems \u2014 an undersized valve restricts flow, while an oversized valve causes poor control, energy waste, and potential instability.<\/p>\r\n\r\n    <h3>Cv vs. Kv \u2014 What's the Difference?<\/h3>\r\n    <p>The <strong>Kv value<\/strong> is the metric equivalent of Cv. It is defined as the flow of water in m\u00b3\/h at a temperature of 5\u201330\u00b0C with a pressure drop of 1 bar across the valve. The two coefficients relate to each other through the conversion factor:<\/p>\r\n\r\n    <div class=\"xv-formula-box\">\r\n      <div class=\"formula\">Cv = 1.156 \u00d7 Kv<\/div>\r\n      <div class=\"formula-desc\">\r\n        <span>Cv<\/span> imperial (GPM, psi) &nbsp;\u27f7&nbsp; <span>Kv<\/span> metric (m\u00b3\/h, bar)\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <p>Cv is predominantly used in North America, while Kv is standard throughout Europe and Asia. When sourcing valves internationally, always confirm which coefficient the manufacturer has specified to avoid sizing errors.<\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-content-section\">\r\n  <div class=\"xv-content-inner\">\r\n    <h2>How to Calculate Cv for Valve Sizing<\/h2>\r\n\r\n    <h3>For Liquids<\/h3>\r\n    <p>The standard formula for calculating Cv with incompressible fluids (liquids) is:<\/p>\r\n    <div class=\"xv-formula-box\">\r\n      <div class=\"formula\">Cv = Q \u00d7 \u221a(SG \/ \u0394P)<\/div>\r\n      <div class=\"formula-desc\">\r\n        <span>Q<\/span> = flow rate (GPM) &emsp; <span>SG<\/span> = specific gravity &emsp; <span>\u0394P<\/span> = P\u2081 \u2212 P\u2082 (psi)\r\n      <\/div>\r\n    <\/div>\r\n    <p>Specific gravity (SG) is the ratio of the fluid's density to the density of water. For water at 60\u00b0F, SG = 1.00. Heavier fluids like sea water (SG \u2248 1.03) require a slightly higher Cv, while lighter fluids like gasoline (SG \u2248 0.75) require less.<\/p>\r\n\r\n    <h3>For Gases<\/h3>\r\n    <p>Gas calculations are more complex because gases are compressible. The formula depends on whether the flow is in a sub-critical or critical (choked) condition:<\/p>\r\n    <div class=\"xv-formula-box\">\r\n      <div class=\"formula\" style=\"font-size:clamp(14px,2.5vw,20px);\">Sub-critical: Cv = Q \/ (16.05 \u00d7 \u221a((P\u2081\u00b2 \u2212 P\u2082\u00b2) \/ (SG \u00d7 T)))<\/div>\r\n      <div class=\"formula-desc\" style=\"margin-top: 12px;\">\r\n        <span>T<\/span> = absolute temp (\u00b0R = \u00b0F + 460) &emsp; Applies when P\u2081 &lt; 2 \u00d7 P\u2082\r\n      <\/div>\r\n    <\/div>\r\n    <div class=\"xv-formula-box\" style=\"margin-top: 12px;\">\r\n      <div class=\"formula\" style=\"font-size:clamp(14px,2.5vw,20px);\">Critical: Cv = Q \/ (6.95 \u00d7 P\u2081 \u00d7 \u221a(1 \/ (SG \u00d7 T)))<\/div>\r\n      <div class=\"formula-desc\" style=\"margin-top: 12px;\">\r\n        Applies when P\u2081 \u2265 2 \u00d7 P\u2082 (choked flow)\r\n      <\/div>\r\n    <\/div>\r\n    <p>In the critical (choked) flow regime, increasing pressure differential no longer increases flow \u2014 the gas has reached sonic velocity at the valve's minimum cross section. Our calculator above automatically detects which formula to use based on your pressure inputs.<\/p>\r\n\r\n    <h3>Step-by-Step Calculation Example<\/h3>\r\n    <p><strong>Scenario:<\/strong> You need to pass 25 GPM of water through a control valve. The upstream pressure is 80 psi and the downstream is 60 psi.<\/p>\r\n    <p>Step 1: \u0394P = 80 \u2212 60 = 20 psi. Step 2: SG for water = 1.00. Step 3: Cv = 25 \u00d7 \u221a(1.00 \/ 20) = 25 \u00d7 0.2236 = <strong>5.59<\/strong>. You would then select a valve with a rated Cv of at least 5.59 \u2014 typically rounding up to the next standard size to provide a safety margin.<\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-content-section\">\r\n  <div class=\"xv-content-inner\">\r\n    <h2>Typical Cv Values by Valve Type and Size<\/h2>\r\n    <p>The table below provides representative Cv values for common industrial valve types at full open position. Actual values vary by manufacturer, design, and trim \u2014 always consult the specific valve datasheet for precise Cv data.<\/p>\r\n\r\n    <div class=\"xv-table-wrap\">\r\n      <table class=\"xv-table\">\r\n        <thead>\r\n          <tr>\r\n            <th>Valve Type<\/th>\r\n            <th>\u00bd\u2033<\/th>\r\n            <th>1\u2033<\/th>\r\n            <th>2\u2033<\/th>\r\n            <th>4\u2033<\/th>\r\n            <th>6\u2033<\/th>\r\n            <th>8\u2033<\/th>\r\n          <\/tr>\r\n        <\/thead>\r\n        <tbody>\r\n          <tr>\r\n            <td><strong>Ball Valve<\/strong> (Full Bore)<\/td>\r\n            <td class=\"mono\">30<\/td>\r\n            <td class=\"mono\">100<\/td>\r\n            <td class=\"mono\">400<\/td>\r\n            <td class=\"mono\">1,600<\/td>\r\n            <td class=\"mono\">3,500<\/td>\r\n            <td class=\"mono\">6,500<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Ball Valve<\/strong> (Reduced Bore)<\/td>\r\n            <td class=\"mono\">15<\/td>\r\n            <td class=\"mono\">50<\/td>\r\n            <td class=\"mono\">180<\/td>\r\n            <td class=\"mono\">750<\/td>\r\n            <td class=\"mono\">1,600<\/td>\r\n            <td class=\"mono\">3,200<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Gate Valve<\/strong><\/td>\r\n            <td class=\"mono\">8<\/td>\r\n            <td class=\"mono\">35<\/td>\r\n            <td class=\"mono\">160<\/td>\r\n            <td class=\"mono\">640<\/td>\r\n            <td class=\"mono\">1,400<\/td>\r\n            <td class=\"mono\">2,800<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Globe Valve<\/strong><\/td>\r\n            <td class=\"mono\">4<\/td>\r\n            <td class=\"mono\">14<\/td>\r\n            <td class=\"mono\">55<\/td>\r\n            <td class=\"mono\">200<\/td>\r\n            <td class=\"mono\">450<\/td>\r\n            <td class=\"mono\">800<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Butterfly Valve<\/strong><\/td>\r\n            <td class=\"mono\">\u2014<\/td>\r\n            <td class=\"mono\">\u2014<\/td>\r\n            <td class=\"mono\">110<\/td>\r\n            <td class=\"mono\">680<\/td>\r\n            <td class=\"mono\">1,800<\/td>\r\n            <td class=\"mono\">3,800<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Check Valve<\/strong> (Swing)<\/td>\r\n            <td class=\"mono\">5<\/td>\r\n            <td class=\"mono\">25<\/td>\r\n            <td class=\"mono\">120<\/td>\r\n            <td class=\"mono\">500<\/td>\r\n            <td class=\"mono\">1,100<\/td>\r\n            <td class=\"mono\">2,200<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td><strong>Plug Valve<\/strong><\/td>\r\n            <td class=\"mono\">10<\/td>\r\n            <td class=\"mono\">40<\/td>\r\n            <td class=\"mono\">170<\/td>\r\n            <td class=\"mono\">700<\/td>\r\n            <td class=\"mono\">1,500<\/td>\r\n            <td class=\"mono\">3,000<\/td>\r\n          <\/tr>\r\n        <\/tbody>\r\n      <\/table>\r\n    <\/div>\r\n\r\n    <p><em>Note: Values are approximate and based on typical industrial-grade valves. For critical applications, always reference the manufacturer's published Cv data. Xintai Valves provides Cv data for every valve in our catalog \u2014 <a href=\"https:\/\/www.xintaivalves.com\/contact\/\" style=\"color:var(--accent);\">contact us<\/a> for specific product datasheets.<\/em><\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-content-section\">\r\n  <div class=\"xv-content-inner\">\r\n    <h2>Factors That Affect Valve Flow Coefficient<\/h2>\r\n    <p>Understanding the variables that influence Cv helps engineers and procurement teams make better valve selection decisions:<\/p>\r\n    <p><strong>Valve Type and Design:<\/strong> Full-bore ball valves provide near-zero flow restriction and the highest Cv values relative to their size. Globe valves, by contrast, force fluid through a tortuous path and have significantly lower Cv \u2014 but they offer superior throttling control. Butterfly valves and plug valves fall between these extremes.<\/p>\r\n    <p><strong>Valve Opening Percentage:<\/strong> Published Cv values are typically for a fully open valve. At partial openings, the effective Cv decreases according to the valve's inherent flow characteristic curve \u2014 linear, equal-percentage, or quick-opening. Control valve selection must account for Cv at the normal operating position, not just fully open.<\/p>\r\n    <p><strong>Port Size and Bore Geometry:<\/strong> A reduced-bore ball valve may have 50% or less of the Cv of a full-bore version in the same pipe size. When pressure drop is critical, specifying full-bore construction preserves system flow capacity.<\/p>\r\n    <p><strong>Fluid Properties:<\/strong> Viscous fluids (heavy oils, slurries) experience greater resistance than water, effectively reducing the useful flow through a given Cv. For highly viscous fluids (Re &lt; 10,000), a viscosity correction factor should be applied to the standard Cv calculation.<\/p>\r\n    <p><strong>Cavitation and Flashing:<\/strong> In liquid service, if the pressure at the valve vena contracta drops below the fluid's vapor pressure, cavitation or flashing can occur \u2014 reducing effective Cv and potentially causing severe valve damage. Proper valve sizing must include a cavitation analysis for critical applications.<\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-content-section\">\r\n  <div class=\"xv-content-inner\">\r\n    <h2>How to Select the Right Valve Using Cv<\/h2>\r\n    <p>Once you've calculated the required Cv for your application using the tool above, follow these steps for proper valve selection:<\/p>\r\n    <p><strong>1. Match Cv with a safety margin.<\/strong> Select a valve whose rated Cv exceeds your calculated value by 15\u201325%. This margin accommodates flow variations, fouling, and manufacturing tolerances. However, avoid excessive oversizing \u2014 a valve constantly operating at less than 20% of its Cv range provides poor control.<\/p>\r\n    <p><strong>2. Check the operating Cv range.<\/strong> For control valves, ensure the required Cv at minimum and maximum flow conditions falls within the valve's controllable range (typically 50:1 for modern globe valves). The valve should operate between 20% and 80% open for optimal control.<\/p>\r\n    <p><strong>3. Consider process conditions.<\/strong> Beyond Cv, verify the valve's pressure rating (ANSI class), temperature rating, material compatibility with your media, and end connections match your piping specifications.<\/p>\r\n    <p><strong>4. Evaluate the total cost of ownership.<\/strong> A properly sized valve reduces energy costs (lower pumping power), extends valve life (less wear from cavitation or throttling at extremes), and minimizes maintenance downtime. Investing in the correct valve specification from the start saves significantly over the life of the system.<\/p>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-cta-section\">\r\n  <div class=\"xv-cta-inner\">\r\n    <h2>Need Valves with Verified Cv Data?<\/h2>\r\n    <p>Xintai Valves manufactures ball valves, gate valves, globe valves, butterfly valves, and check valves with certified flow coefficient data. Share your Cv requirements and our engineers will recommend the optimal valve specification \u2014 delivered factory-direct at competitive pricing.<\/p>\r\n    <a href=\"https:\/\/www.xintaivalves.com\/contact\/\" class=\"xv-btn-cta\">Request a Quote \u2192<\/a>\r\n    <div class=\"xv-cta-trust\">\r\n      <span>\u2713 ISO 9001 Certified<\/span>\r\n      <span>\u2713 API 600 \/ API 6D<\/span>\r\n      <span>\u2713 CE \/ PED Compliant<\/span>\r\n      <span>\u2713 Factory-Direct Pricing<\/span>\r\n    <\/div>\r\n  <\/div>\r\n<\/section>\r\n\r\n<section class=\"xv-faq-section\" id=\"faq\">\r\n  <div class=\"xv-faq-inner\">\r\n    <h2>Frequently Asked Questions<\/h2>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">What is a good Cv value for a valve?<\/button>\r\n      <div class=\"xv-faq-a\"><p>There is no universal \"good\" Cv \u2014 the right value depends entirely on your application's required flow rate, allowable pressure drop, and fluid properties. A 2-inch ball valve may have a Cv of 400, while a 2-inch globe valve may only offer a Cv of 55. The key is calculating the Cv your system needs (using the calculator above) and then selecting a valve with a matching or slightly higher rated Cv.<\/p><\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">How do I convert Cv to Kv?<\/button>\r\n      <div class=\"xv-faq-a\"><p>The conversion is straightforward: Kv = Cv \u00f7 1.156 (or equivalently, Cv = Kv \u00d7 1.156). Cv is the imperial standard used in North America (flow in GPM with 1 psi drop), while Kv is the metric standard used in Europe and Asia (flow in m\u00b3\/h with 1 bar drop). Use our Cv-Kv converter above for instant conversion.<\/p><\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">Why is my valve's actual flow less than the calculated Cv suggests?<\/button>\r\n      <div class=\"xv-faq-a\"><p>Several factors can reduce actual flow below theoretical Cv predictions: the valve may not be fully open, upstream piping may introduce additional pressure losses, the fluid viscosity may be higher than water (reducing effective Cv), or the system may be experiencing cavitation. Pipe fittings, reducers, and bends near the valve also affect the real pressure drop. Always consider the entire system \u2014 not just the valve \u2014 when analyzing flow performance.<\/p><\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">What is the difference between Cv and Av flow coefficients?<\/button>\r\n      <div class=\"xv-faq-a\"><p>Av is another flow coefficient that uses SI units (flow in m\u00b3\/s, density in kg\/m\u00b3). The relationship is: Cv = Av \u00d7 10\u207b\u00b2 \/ 79, or equivalently Av = Kv \u00d7 10\u2076 \/ 28. In practice, Cv and Kv are far more commonly used in valve specifications. If you encounter an Av value, convert it to Cv or Kv for easier comparison across manufacturer catalogs.<\/p><\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">Does valve position affect Cv?<\/button>\r\n      <div class=\"xv-faq-a\"><p>Yes. The published Cv is for a fully open valve. At partial openings, the effective Cv follows the valve's inherent flow characteristic curve. Linear-characteristic valves have a Cv that decreases proportionally with closure. Equal-percentage valves (common in globe valves) have a Cv that changes logarithmically. This is critical for control valve sizing \u2014 engineers must ensure the Cv at the expected operating position (not just fully open) meets the system requirements.<\/p><\/div>\r\n    <\/div>\r\n\r\n    <div class=\"xv-faq-item\">\r\n      <button class=\"xv-faq-q\" onclick=\"toggleFaq(this)\">Can I use the Cv calculator for steam applications?<\/button>\r\n      <div class=\"xv-faq-a\"><p>Steam is a special case. Saturated steam can be sized using gas flow equations with appropriate specific gravity (approximately 0.6 relative to air, depending on pressure). However, for superheated steam or two-phase flow, the standard Cv formulas require additional correction factors. For critical steam applications, we recommend consulting with our engineering team for a detailed sizing analysis specific to your conditions.<\/p><\/div>\r\n    <\/div>\r\n  <\/div>\r\n<\/section>\r\n\r\n<div class=\"xv-disclaimer\">\r\n  <p>This calculator provides estimated values for preliminary valve sizing. For critical applications, consult a qualified engineer. Results stroke should be verified against manufacturer-specific data before final valve selection.<\/p>\r\n<\/div>\r\n\r\n<script type=\"application\/ld+json\">\r\n{\r\n  \"@context\": \"https:\/\/schema.org\",\r\n  \"@type\": \"FAQPage\",\r\n  \"mainEntity\": [\r\n    {\r\n      \"@type\": \"Question\",\r\n      \"name\": \"What is a good Cv value for a valve?\",\r\n      \"acceptedAnswer\": {\r\n        \"@type\": \"Answer\",\r\n        \"text\": \"There is no universal good Cv \u2014 the right value depends on your application's required flow rate, allowable pressure drop, and fluid properties. A 2-inch ball valve may have a Cv of 400, while a 2-inch globe valve may only offer a Cv of 55. Calculate the Cv your system needs and then select a valve with a matching or slightly higher rated Cv.\"\r\n      }\r\n    },\r\n    {\r\n      \"@type\": \"Question\",\r\n      \"name\": \"How do I convert Cv to Kv?\",\r\n      \"acceptedAnswer\": {\r\n        \"@type\": \"Answer\",\r\n        \"text\": \"Kv = Cv \u00f7 1.156 (or Cv = Kv \u00d7 1.156). Cv is the imperial standard (GPM with 1 psi drop), while Kv is the metric standard (m\u00b3\/h with 1 bar drop).\"\r\n      }\r\n    },\r\n    {\r\n      \"@type\": \"Question\",\r\n      \"name\": \"Why is my valve's actual flow less than the calculated Cv suggests?\",\r\n      \"acceptedAnswer\": {\r\n        \"@type\": \"Answer\",\r\n        \"text\": \"Factors that reduce actual flow include: valve not fully open, upstream piping pressure losses, higher fluid viscosity, cavitation, and nearby pipe fittings or reducers. 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Control valve sizing must ensure Cv at the expected operating position meets system requirements.\"\r\n      }\r\n    },\r\n    {\r\n      \"@type\": \"Question\",\r\n      \"name\": \"Can I use the Cv calculator for steam applications?\",\r\n      \"acceptedAnswer\": {\r\n        \"@type\": \"Answer\",\r\n        \"text\": \"Saturated steam can be sized using gas flow equations with appropriate specific gravity (approximately 0.6 relative to air). For superheated steam or two-phase flow, additional correction factors are needed. Consult a qualified engineer for critical steam sizing.\"\r\n      }\r\n    }\r\n  ]\r\n}\r\n<\/script>\r\n\r\n<script type=\"application\/ld+json\">\r\n{\r\n  \"@context\": \"https:\/\/schema.org\",\r\n  \"@type\": \"HowTo\",\r\n  \"name\": \"How to Calculate Valve Cv (Flow Coefficient)\",\r\n  \"description\": \"Step-by-step guide to calculate the valve flow coefficient for proper valve sizing in liquid applications.\",\r\n  \"step\": [\r\n    {\r\n      \"@type\": \"HowToStep\",\r\n      \"name\": \"Determine pressure drop\",\r\n      \"text\": \"Measure or calculate the inlet pressure (P1) and outlet pressure (P2). The pressure drop \u0394P = P1 \u2212 P2.\"\r\n    },\r\n    {\r\n      \"@type\": \"HowToStep\",\r\n      \"name\": \"Identify fluid specific gravity\",\r\n      \"text\": \"Determine the specific gravity (SG) of your fluid relative to water. Water = 1.00 at 60\u00b0F.\"\r\n    },\r\n    {\r\n      \"@type\": \"HowToStep\",\r\n      \"name\": \"Determine required flow rate\",\r\n      \"text\": \"Establish the required volumetric flow rate (Q) in GPM for your system.\"\r\n    },\r\n    {\r\n      \"@type\": \"HowToStep\",\r\n      \"name\": \"Apply the Cv formula\",\r\n      \"text\": \"Calculate Cv = Q \u00d7 \u221a(SG \/ \u0394P). For gases, use the compressible flow formula with temperature correction.\"\r\n    },\r\n    {\r\n      \"@type\": \"HowToStep\",\r\n      \"name\": \"Select a valve\",\r\n      \"text\": \"Choose a valve with a rated Cv that exceeds your calculated value by 15-25% for a safety margin.\"\r\n    }\r\n  ]\r\n}\r\n<\/script>\r\n\r\n<\/div>\r\n\r\n<script>\r\n(function() {\r\n  \/\/ State\r\n  let calcType = 'cv';\r\n  let mediumType = 'liquid';\r\n\r\n  \/\/ Unit conversions \u2192 all to psi\r\n  const toPsi = { psi: 1, bar: 14.5038, kpa: 0.145038, mpa: 145.038 };\r\n  \/\/ Flow conversions \u2192 all to GPM (liquid) or SCFM (gas)\r\n  const toGPM = { gpm: 1, lpm: 0.264172, m3h: 4.40287 };\r\n  const toSCFM = { scfm: 1, 'stdl\/min': 0.0353147, 'stdm3\/h': 0.588578 };\r\n\r\n  window.setCalcType = function(type) {\r\n    calcType = type;\r\n    document.querySelectorAll('#calcTypeGroup .xv-toggle-btn').forEach(b => {\r\n      b.classList.toggle('active', b.dataset.value === type);\r\n    });\r\n    document.getElementById('flowField').style.display = type === 'cv' ? 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'' : 'none';\r\n    document.getElementById('sgField').style.display = 'none';\r\n    updateFlowUnits();\r\n    hideResult();\r\n  };\r\n\r\n  function updateFlowUnits() {\r\n    const sel = document.getElementById('flowUnit');\r\n    sel.innerHTML = '';\r\n    if (mediumType === 'liquid') {\r\n      [['gpm','GPM'],['lpm','L\/min'],['m3h','m\u00b3\/h']].forEach(([v,t]) => {\r\n        const o = document.createElement('option'); o.value = v; o.textContent = t; sel.appendChild(o);\r\n      });\r\n    } else {\r\n      [['scfm','SCFM'],['stdl\/min','std L\/min'],['stdm3\/h','std m\u00b3\/h']].forEach(([v,t]) => {\r\n        const o = document.createElement('option'); o.value = v; o.textContent = t; sel.appendChild(o);\r\n      });\r\n    }\r\n  }\r\n\r\n  window.updateSG = function() {\r\n    const val = document.getElementById('medium').value;\r\n    document.getElementById('sgField').style.display = val === 'custom' ? '' : 'none';\r\n    if (val !== 'custom') document.getElementById('sgInput').value = val;\r\n  };\r\n  window.updateGasSG = function() {\r\n    const val = document.getElementById('gasMedium').value;\r\n    document.getElementById('sgField').style.display = val === 'custom' ? '' : 'none';\r\n    if (val !== 'custom') document.getElementById('sgInput').value = val;\r\n  };\r\n\r\n  function getSG() {\r\n    if (mediumType === 'liquid') {\r\n      const v = document.getElementById('medium').value;\r\n      return v === 'custom' ? parseFloat(document.getElementById('sgInput').value) : parseFloat(v);\r\n    } else {\r\n      const v = document.getElementById('gasMedium').value;\r\n      return v === 'custom' ? parseFloat(document.getElementById('sgInput').value) : parseFloat(v);\r\n    }\r\n  }\r\n\r\n  function showError(msg) {\r\n    const el = document.getElementById('errorMsg');\r\n    el.textContent = msg;\r\n    el.classList.add('show');\r\n  }\r\n  function hideError() {\r\n    document.getElementById('errorMsg').classList.remove('show');\r\n    document.getElementById('errorMsg').textContent = '';\r\n  }\r\n  function hideResult() {\r\n    document.getElementById('resultBox').classList.remove('show');\r\n  }\r\n\r\n  window.calculate = function() {\r\n    hideError();\r\n    hideResult();\r\n\r\n    const p1raw = parseFloat(document.getElementById('p1').value);\r\n    const p2raw = parseFloat(document.getElementById('p2').value);\r\n    const p1unit = document.getElementById('p1Unit').value;\r\n    const p2unit = document.getElementById('p2Unit').value;\r\n\r\n    if (isNaN(p1raw) || isNaN(p2raw)) { showError('Please enter valid values for both P\u2081 and P\u2082.'); return; }\r\n\r\n    const p1 = p1raw * toPsi[p1unit];\r\n    const p2 = p2raw * toPsi[p2unit];\r\n\r\n    if (p1 <= p2) { showError('Inlet pressure (P\u2081) must be greater than outlet pressure (P\u2082).'); return; }\r\n\r\n    const sg = getSG();\r\n    if (isNaN(sg) || sg <= 0) { showError('Please enter a valid specific gravity.'); return; }\r\n\r\n    let result, resultLabel, resultVal, resultUnitText, details;\r\n\r\n    if (mediumType === 'liquid') {\r\n      const dp = p1 - p2;\r\n\r\n      if (calcType === 'cv') {\r\n        const qRaw = parseFloat(document.getElementById('flowRate').value);\r\n        if (isNaN(qRaw) || qRaw <= 0) { showError('Please enter a valid flow rate.'); return; }\r\n        const fUnit = document.getElementById('flowUnit').value;\r\n        const q = qRaw * toGPM[fUnit];\r\n        const cv = q * Math.sqrt(sg \/ dp);\r\n        const kv = cv \/ 1.156;\r\n\r\n        resultLabel = 'CALCULATED Cv VALUE';\r\n        resultVal = cv.toFixed(2);\r\n        resultUnitText = 'Cv (Kv = ' + kv.toFixed(2) + ')';\r\n        details = `\r\n          <div class=\"xv-result-item\">\u0394P (pressure drop)<strong>${dp.toFixed(2)} psi<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Flow rate<strong>${q.toFixed(2)} GPM<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Specific gravity<strong>${sg}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Kv equivalent<strong>${kv.toFixed(2)}<\/strong><\/div>\r\n          <div class=\"xv-result-note\">\ud83d\udca1 Select a valve with a rated Cv \u2265 <strong>${(cv * 1.2).toFixed(1)}<\/strong> (includes 20% safety margin) for reliable performance.<\/div>\r\n        `;\r\n      } else {\r\n        const cvIn = parseFloat(document.getElementById('cvInput').value);\r\n        if (isNaN(cvIn) || cvIn <= 0) { showError('Please enter a valid Cv value.'); return; }\r\n        const q = cvIn * Math.sqrt(dp \/ sg);\r\n        resultLabel = 'CALCULATED FLOW RATE';\r\n        resultVal = q.toFixed(2);\r\n        resultUnitText = 'GPM';\r\n        details = `\r\n          <div class=\"xv-result-item\">\u0394P (pressure drop)<strong>${dp.toFixed(2)} psi<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Cv used<strong>${cvIn}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">L\/min equivalent<strong>${(q \/ 0.264172).toFixed(1)}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">m\u00b3\/h equivalent<strong>${(q \/ 4.40287).toFixed(2)}<\/strong><\/div>\r\n        `;\r\n      }\r\n    } else {\r\n      \/\/ Gas\r\n      let tempF;\r\n      const tempRaw = parseFloat(document.getElementById('temp').value);\r\n      if (isNaN(tempRaw)) { showError('Please enter a valid temperature.'); return; }\r\n      const tempUnit = document.getElementById('tempUnit').value;\r\n      tempF = tempUnit === 'C' ? (tempRaw * 9\/5) + 32 : tempRaw;\r\n      const T = tempF + 460; \/\/ Rankine\r\n\r\n      const isCritical = p1 >= 2 * p2;\r\n\r\n      if (calcType === 'cv') {\r\n        const qRaw = parseFloat(document.getElementById('flowRate').value);\r\n        if (isNaN(qRaw) || qRaw <= 0) { showError('Please enter a valid flow rate.'); return; }\r\n        const fUnit = document.getElementById('flowUnit').value;\r\n        \/\/ Convert to SCFM\r\n        let q;\r\n        if (fUnit === 'scfm') q = qRaw;\r\n        else if (fUnit === 'stdl\/min') q = qRaw * 0.0353147;\r\n        else if (fUnit === 'stdm3\/h') q = qRaw * 0.588578;\r\n        else q = qRaw; \/\/ fallback\r\n\r\n        let cv;\r\n        if (isCritical) {\r\n          cv = q \/ (6.95 * p1 * Math.sqrt(1 \/ (sg * T)));\r\n        } else {\r\n          cv = q \/ (16.05 * Math.sqrt((p1*p1 - p2*p2) \/ (sg * T)));\r\n        }\r\n        const kv = cv \/ 1.156;\r\n\r\n        resultLabel = 'CALCULATED Cv VALUE (GAS)';\r\n        resultVal = cv.toFixed(2);\r\n        resultUnitText = 'Cv (Kv = ' + kv.toFixed(2) + ')';\r\n        details = `\r\n          <div class=\"xv-result-item\">Flow regime<strong>${isCritical ? 'Critical (choked)' : 'Sub-critical'}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Temperature<strong>${tempF.toFixed(0)}\u00b0F (${T.toFixed(0)}\u00b0R)<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Flow rate<strong>${q.toFixed(2)} SCFM<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Kv equivalent<strong>${kv.toFixed(2)}<\/strong><\/div>\r\n          <div class=\"xv-result-note\">\ud83d\udca1 Gas flow is ${isCritical ? '<strong>choked<\/strong> \u2014 increasing \u0394P will not increase flow beyond this point' : '<strong>sub-critical<\/strong> \u2014 flow increases with larger pressure differential'}. Select a valve with rated Cv \u2265 <strong>${(cv * 1.2).toFixed(1)}<\/strong>.<\/div>\r\n        `;\r\n      } else {\r\n        const cvIn = parseFloat(document.getElementById('cvInput').value);\r\n        if (isNaN(cvIn) || cvIn <= 0) { showError('Please enter a valid Cv value.'); return; }\r\n\r\n        let q;\r\n        if (isCritical) {\r\n          q = 6.95 * cvIn * p1 * Math.sqrt(1 \/ (sg * T));\r\n        } else {\r\n          q = 16.05 * cvIn * Math.sqrt((p1*p1 - p2*p2) \/ (sg * T));\r\n        }\r\n\r\n        resultLabel = 'CALCULATED FLOW RATE (GAS)';\r\n        resultVal = q.toFixed(2);\r\n        resultUnitText = 'SCFM';\r\n        details = `\r\n          <div class=\"xv-result-item\">Flow regime<strong>${isCritical ? 'Critical (choked)' : 'Sub-critical'}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Temperature<strong>${tempF.toFixed(0)}\u00b0F (${T.toFixed(0)}\u00b0R)<\/strong><\/div>\r\n          <div class=\"xv-result-item\">Cv used<strong>${cvIn}<\/strong><\/div>\r\n          <div class=\"xv-result-item\">std L\/min equivalent<strong>${(q \/ 0.0353147).toFixed(1)}<\/strong><\/div>\r\n        `;\r\n      }\r\n    }\r\n\r\n    \/\/ Show result\r\n    const box = document.getElementById('resultBox');\r\n    document.getElementById('resultLabel').textContent = resultLabel;\r\n    document.getElementById('resultValue').textContent = resultVal;\r\n    document.getElementById('resultUnit').textContent = resultUnitText;\r\n    document.getElementById('resultDetail').innerHTML = details;\r\n    box.classList.add('show');\r\n    box.scrollIntoView({ behavior: 'smooth', block: 'center' });\r\n  };\r\n\r\n  window.resetCalc = function() {\r\n    hideError(); hideResult();\r\n    document.querySelectorAll('.xv-calc-card input[type=number]').forEach(i => i.value = '');\r\n    document.getElementById('medium').selectedIndex = 0;\r\n    document.getElementById('gasMedium').selectedIndex = 0;\r\n    document.getElementById('sgInput').value = '1.0';\r\n    document.getElementById('temp').value = '68';\r\n  };\r\n\r\n  \/\/ Cv \u2194 Kv converter\r\n  window.convertCvKv = function(from) {\r\n    if (from === 'cv') {\r\n      const cv = parseFloat(document.getElementById('convCv').value);\r\n      document.getElementById('convKv').value = isNaN(cv) ? '' : (cv \/ 1.156).toFixed(4);\r\n    } else {\r\n      const kv = parseFloat(document.getElementById('convKv').value);\r\n      document.getElementById('convCv').value = isNaN(kv) ? '' : (kv * 1.156).toFixed(4);\r\n    }\r\n  };\r\n\r\n  \/\/ FAQ toggle\r\n  window.toggleFaq = function(btn) {\r\n    const a = btn.nextElementSibling;\r\n    const isOpen = a.classList.contains('open');\r\n    document.querySelectorAll('.xv-faq-a').forEach(el => el.classList.remove('open'));\r\n    document.querySelectorAll('.xv-faq-q').forEach(el => el.classList.remove('open'));\r\n    if (!isOpen) { a.classList.add('open'); btn.classList.add('open'); }\r\n  };\r\n})();\r\n<\/script>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Home\u203a Resources\u203a Valve Cv Calculator Valve Cv Calculator \u2014 Flow Coefficient for Valve Sizing Calculate valve flow coefficient (Cv) or flow rate for liquid and gas applications. Use our free tool to properly size control valves, ball valves, gate valves, and butterfly valves \u2014 then get a quote from our factory. Valve Cv \/ Flow [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-14825","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/pages\/14825","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/comments?post=14825"}],"version-history":[{"count":35,"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/pages\/14825\/revisions"}],"predecessor-version":[{"id":14862,"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/pages\/14825\/revisions\/14862"}],"wp:attachment":[{"href":"https:\/\/www.xintaivalves.com\/ar\/wp-json\/wp\/v2\/media?parent=14825"}],"curies":[{"name":"\u0648\u0648\u0631\u062f\u0628\u0631\u064a\u0633","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}