{"id":31593,"date":"2025-09-10T11:08:00","date_gmt":"2025-09-10T03:08:00","guid":{"rendered":"https:\/\/stark-water.com\/?p=31593"},"modified":"2026-04-01T16:00:15","modified_gmt":"2026-04-01T08:00:15","slug":"ro-membrane","status":"publish","type":"post","link":"https:\/\/stark-water.com\/ko\/%eb%b8%94%eb%a1%9c%ea%b7%b8\/ro-membrane\/","title":{"rendered":"RO \uba64\ube0c\ub808\uc778 \ubb38\uc81c \ud574\uacb0: \ub0ae\uc740 \uc720\ub7c9, \ub192\uc740 TDS, \ub192\uc740 \u0394P"},"content":{"rendered":"<p><strong>ro membrane troubleshooting<\/strong>&nbsp;starts with data: normalized permeate flow, salt rejection, and differential pressure. This guide shows the fastest checks, a symptom-to-cause matrix, and exact tests and fixes for 1812\/4040\/8040 systems.<\/p>\n\n\n\n<p><a href=\"\/ko\/ro-membrane-cleaning\/\">CIP and Cleaning Guide<\/a>&nbsp;<a href=\"\/ko\/%eb%a1%9c-%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8-%ea%b5%90%ec%b2%b4\/\">\uad50\uccb4 \uccb4\ud06c\ub9ac\uc2a4\ud2b8<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Quick Checks<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Confirm valves and orientation: feed open, concentrate partially throttled, permeate to drain during start-up.<\/li>\n\n\n\n<li>Bypass tanks and post-filters during testing to remove backpressure effects.<\/li>\n\n\n\n<li>Replace clogged cartridges and verify dechlorination before TFC membranes.<\/li>\n\n\n\n<li>Record temperature, pressure at feed\/concentrate\/permeate, and TDS of feed and permeate.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">ro membrane troubleshooting \u2014 key causes and thresholds<\/h2>\n\n\n\n<p>\ud6a8\uacfc\uc801 <strong>ro membrane troubleshooting<\/strong> focuses on three signals: normalized permeate flow, salt rejection, and differential pressure. Clean when normalized flow drops about 10\u201315% or when \u0394P exceeds supplier limits. Replace when rejection or flow cannot be restored to 90\u201395% of the clean baseline, or when oxidation damage or leakage is confirmed at end caps or interconnectors.<\/p>\n\n\n\n<p>Always compare data at similar temperature and recovery. Many \u201clow-flow\u201d complaints are seasonal temperature effects; many \u201chigh-TDS\u201d cases are actually backpressure from tanks or valves. Normalize first, then diagnose.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-1024x683.webp\" alt=\"ro-plant-technician-inspecting-gauges\" class=\"wp-image-31615\" title=\"\" srcset=\"https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-1024x683.webp 1024w, https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-300x200.webp 300w, https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-768x512.webp 768w, https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-18x12.webp 18w, https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges-600x400.webp 600w, https:\/\/stark-water.com\/wp-content\/uploads\/2025\/09\/ro-plant-technician-inspecting-gauges.webp 1536w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">ro-plant-technician-inspecting-gauges<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Symptom-to-Cause Troubleshooting Matrix<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\uc99d\uc0c1<\/th><th>Likely Causes<\/th><th>Tests<\/th><th>Fix<\/th><\/tr><\/thead><tbody><tr><td>Low permeate flow<\/td><td>Fouled membrane; clogged cartridges; low feed pressure; cold water; recovery too high<\/td><td>Normalized flow vs baseline; \u0394P per stage; check pump curve and temp<\/td><td>CIP for the fouling type; replace cartridges; raise pressure within limits; reduce recovery<\/td><\/tr><tr><td>High permeate TDS \/ poor rejection<\/td><td>Oxidation damage; membrane end-cap leak; interconnector issue; extreme recovery<\/td><td>Salt rejection test; check chlorine upstream; pressure hold test; inspect seals<\/td><td>Replace damaged elements; fix leaks and orientation; correct recovery and backpressure<\/td><\/tr><tr><td>High differential pressure (\u0394P)<\/td><td>Particulate\/colloidal fouling; biofouling; iron\/manganese scale<\/td><td>SDI\/NTU; ATP\/biological tests; Fe\/Mn tests; visual sludge<\/td><td>Alkaline CIP for organics\/bio; dispersant; reducing agent for iron; improve pretreatment<\/td><\/tr><tr><td>Frequent cleanings but no recovery<\/td><td>Wrong chemistry\/temperature; irreversible damage; persistent upstream issue<\/td><td>Post-CIP rejection\/flow vs baseline; inspect for oxidation; review antiscalant dosing<\/td><td>Switch chemistry and temp; repair root cause; schedule replacement<\/td><\/tr><tr><td>Noisy pump \/ cavitation<\/td><td>Starved suction; blocked strainers; air ingress<\/td><td>NPSH check; suction pressure; inspect for air leaks<\/td><td>Open valves; clean strainers; fix suction plumbing and priming<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Key Tests: Rejection and Normalized Flow<\/h2>\n\n\n\n<h2 class=\"wp-block-heading\">Acceptance criteria and baselines<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Set a clean baseline for each stage: normalized permeate flow, rejection, and \u0394P at reference temperature.<\/li>\n\n\n\n<li>Use the same meters and units to avoid false trends; document every CIP and changeout.<\/li>\n\n\n\n<li>During <strong>ro membrane troubleshooting<\/strong>, test with permeate to drain so backpressure does not distort readings.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Salt Rejection (single-pass)<\/h3>\n\n\n\n<p>Rejection (%) = (1 \u2212 permeate TDS \/ feed TDS) \u00d7 100. Compare to your new-element baseline under similar temperature.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Normalized Permeate Flow<\/h3>\n\n\n\n<p>Correct flow to a reference temperature and pressure so day-to-day results are comparable. Most suppliers provide a correction factor table or equation. Track normalized flow per stage and compare with the clean baseline.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">ro membrane troubleshooting \u2014 step-by-step rejection test<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Flush to stable operation; divert permeate to drain for several minutes.<\/li>\n\n\n\n<li>Measure feed and permeate TDS and temperature with calibrated meters.<\/li>\n\n\n\n<li>Compute rejection and record alongside pressure and flow.<\/li>\n\n\n\n<li>If rejection falls beyond acceptance criteria and does not improve after CIP, schedule replacement.<\/li>\n<\/ol>\n\n\n\n<p>See the full cleaning procedure in&nbsp;<a href=\"\/ko\/ro-membrane-cleaning\/\">RO \uba64\ube0c\ub808\uc778 \uccad\uc18c<\/a>.<\/p>\n\n\n\n<p>This checklist shortens <strong>ro membrane troubleshooting<\/strong> by confirming valves, removing backpressure, and normalizing data before deeper tests.<\/p>\n\n\n\n<p>Log results after every <strong>ro membrane troubleshooting<\/strong> session so future drift is obvious and preventive actions can be scheduled.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Sensor and Setup Errors<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Miscalibrated TDS or conductivity meters cause false rejection alarms; calibrate regularly.<\/li>\n\n\n\n<li>Permeate backpressure from tanks or valves inflates TDS and reduces flow; test to drain.<\/li>\n\n\n\n<li>Mixed units or wrong temperature input during normalization leads to false trends.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Clean or Replace?<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Clean<\/strong>\u00a0when normalized flow drops about 10\u201315 percent or \u0394P exceeds limits.<\/li>\n\n\n\n<li><strong>Replace<\/strong>\u00a0when rejection or flow cannot be restored to 90\u201395 percent of baseline or oxidation\/leakage is found.<\/li>\n<\/ul>\n\n\n\n<p>Follow the&nbsp;<a href=\"\/ko\/%eb%a1%9c-%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8-%ea%b5%90%ec%b2%b4\/\">RO \uba64\ube0c\ub808\uc778 \uad50\uccb4<\/a>&nbsp;checklist for safe changeout.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Preventive Maintenance<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Maintain SDI \u2264 supplier limit and change cartridges on pressure drop, not just on calendar.<\/li>\n\n\n\n<li>Verify antiscalant dosage and pH; dechlorinate upstream of TFC membranes.<\/li>\n\n\n\n<li>Log normalized flow, rejection, and \u0394P per stage; trend weekly to catch drift early.<\/li>\n<\/ul>\n\n\n\n<p>For element format and vessel interfaces, see&nbsp;<a href=\"\/ko\/4040-%eb%8c%80-8040-ro-%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8\/\">4040 \ub300 8040 RO \uba64\ube0c\ub808\uc778<\/a>&nbsp;\uadf8\ub9ac\uace0&nbsp;<a href=\"\/ko\/bwro-%eb%8c%80-swro-%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8\/\">BWRO \ub300 SWRO \uba64\ube0c\ub808\uc778<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Common mistakes that waste time<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Comparing raw (unnormalized) flow from winter to summer and calling it a failure.<\/li>\n\n\n\n<li>Running TFC membranes with residual chlorine; rejection will never recover after oxidation.<\/li>\n\n\n\n<li>Testing through tanks and post-filters; permeate backpressure inflates TDS and reduces flow.<\/li>\n\n\n\n<li>Cleaning with the wrong chemistry or too cold; organics\/bio need warm alkaline with surfactant before acid.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\ucc38\uc870<\/h2>\n\n\n\n<p><a href=\"https:\/\/www.dupont.com\/content\/dam\/water\/amer\/us\/en\/water\/public\/documents\/en\/RO-NF-FilmTec-Manual-45-D01504-en.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">\ub4c0\ud3f0 \ud544\ub984\ud14d RO\/NF \uae30\uc220 \ub9e4\ub274\uc5bc<\/a>&nbsp;|&nbsp;<a href=\"https:\/\/www.amtaorg.com\/wp-content\/uploads\/28_Cleaning_in_Place.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">AMTA \ud329\ud2b8 \uc2dc\ud2b8 - \uc81c\uc790\ub9ac \uccad\uc18c(CIP)<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\uc790\uc8fc \ubb3b\ub294 \uc9c8\ubb38<\/h2>\n\n\n\n<p>What is an acceptable salt rejection for a new element?My flow is fine but TDS is high. What should I check?\u0394P climbs within days after cleaning. Why?<\/p>\n\n\n\n<p>For a complete changeout workflow after <strong>ro membrane troubleshooting<\/strong>, see our <a href=\"\/ko\/%eb%a1%9c-%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8-%ea%b5%90%ec%b2%b4\/\">RO \uba64\ube0c\ub808\uc778 \uad50\uccb4<\/a> guide.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Need Help with a Live Issue?<\/h3>\n\n\n\n<p>Send feed TDS\/temperature, stage pressures, normalized flow, and recent CIP history. Our engineer will suggest tests and a corrective plan.<\/p>\n\n\n\n<p><a href=\"\/ko\/product-category\/%ec%88%98%ec%b2%98%eb%a6%ac-%ec%95%a1%ec%84%b8%ec%84%9c%eb%a6%ac\/%eb%a9%a4%eb%b8%8c%eb%a0%88%ec%9d%b8\/\">Order Replacement Membranes<\/a>&nbsp;<a href=\"\/ko\/%ec%88%98%ec%b2%98%eb%a6%ac-%ea%b3%84%ec%82%b0%ea%b8%b0\/ro-sizing\/\">RO \uc0ac\uc774\uc9d5 \uacc4\uc0b0\uae30 \uc0ac\uc6a9<\/a><\/p>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>ro membrane troubleshooting&nbsp;starts with data: normalized permeate flow, salt rejection, and differential pressure. This guide shows the fastest checks, a [&hellip;]<\/p>","protected":false},"author":1,"featured_media":31612,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_joinchat":[],"footnotes":""},"categories":[1],"tags":[236],"class_list":["post-31593","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-water-treatment-industry-information","tag-ro-membrane"],"acf":[],"_links":{"self":[{"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/posts\/31593","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/comments?post=31593"}],"version-history":[{"count":2,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/posts\/31593\/revisions"}],"predecessor-version":[{"id":31616,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/posts\/31593\/revisions\/31616"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/media\/31612"}],"wp:attachment":[{"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/media?parent=31593"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/categories?post=31593"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stark-water.com\/ko\/wp-json\/wp\/v2\/tags?post=31593"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}