{"id":14,"date":"2026-08-31T08:49:11","date_gmt":"2026-08-31T08:49:11","guid":{"rendered":"https:\/\/vas.co.th\/?page_id=14"},"modified":"2026-08-31T10:00:39","modified_gmt":"2026-08-31T10:00:39","slug":"how-to-select-a-pump","status":"publish","type":"page","link":"https:\/\/vas.co.th\/?page_id=14","title":{"rendered":"How to Select a Pump"},"content":{"rendered":"\n<div class=\"vas-page vas-knowledge-article\">\n<section class=\"vas-article-hero vas-section\">\n<div class=\"vas-container vas-article-shell\">\n<nav class=\"vas-breadcrumbs\" aria-label=\"Breadcrumb\"><a href=\"https:\/\/vas.co.th\/\">Home<\/a><span>\/<\/span><a href=\"https:\/\/vas.co.th\/?page_id=9\">Knowledge Center<\/a><span>\/<\/span><span aria-current=\"page\">How to Select a Pump<\/span><\/nav>\n<p class=\"vas-eyebrow\">Water Pumps<\/p>\n<h1>How to Select a Pump<\/h1>\n<p class=\"vas-lead\">Good selection starts with the required duty rather than the motor size or connection diameter alone.<\/p>\n<\/div>\n<\/section>\n<section class=\"vas-section vas-section--white\">\n<div class=\"vas-container vas-article-shell\">\n<article class=\"vas-article-body\">\n<figure class=\"vas-subject-visual vas-local-technical-figure\"><figcaption>\n<p class=\"vas-eyebrow\">Selection guide<\/p>\n<h2>How to Select the Right Water Pump<\/h2>\n<\/figcaption><div class=\"vas-local-technical-figure__viewport\"><a href=\"https:\/\/vas.co.th\/wp-content\/plugins\/vas-site-prototype-plugin\/assets\/technical\/Pump%20selection%20(how%20to%20select%20a%20pump).png\" target=\"_blank\" rel=\"noopener\" aria-label=\"Open How to Select the Right Water Pump at full size\"><img decoding=\"async\" src=\"https:\/\/vas.co.th\/wp-content\/plugins\/vas-site-prototype-plugin\/assets\/technical\/Pump%20selection%20(how%20to%20select%20a%20pump).png\" alt=\"Pump-selection guide covering the duty point, system and pump curves, best efficiency point, and oversized, matched, and undersized pump comparisons.\" loading=\"lazy\"><\/a><\/div>\n<p class=\"vas-photo-credit\">Use this guide as a starting point. Confirm the duty point and final selection with manufacturer performance data.<\/p>\n<\/figure>\n<section class=\"vas-article-lessons\" aria-labelledby=\"vas-article-lessons-title\">\n<header>\n<p class=\"vas-eyebrow\">Key takeaways<\/p>\n<h2 id=\"vas-article-lessons-title\">What to Know<\/h2>\n<p>Scan the main ideas first. Open \u201cKey points\u201d only when you want the supporting details.<\/p>\n<\/header>\n<p class=\"vas-article-lessons__hint\">Swipe the cards to continue <span aria-hidden=\"true\">\u2192<\/span><\/p>\n<div class=\"vas-article-lessons__grid\" role=\"list\" aria-label=\"Article key takeaways\">\n<article class=\"vas-article-lesson\" role=\"listitem\"><span class=\"vas-article-lesson__number\">01<\/span><\/p>\n<h3>Define the Required Duty Point<\/h3>\n<p>The first panel combines required flow and total dynamic head into one target operating point. Flow states how much water must be delivered, while head includes elevation, required outlet pressure, and friction through the complete system.<\/p>\n<details>\n<summary>Key points <span>3<\/span><\/summary>\n<ul>\n<li>Record one flow value and its matching head value<\/li>\n<li>Describe temperature, solids, corrosiveness, and other water conditions<\/li>\n<li>Choose materials compatible with the liquid and environment<\/li>\n<\/ul>\n<\/details>\n<\/article>\n<article class=\"vas-article-lesson\" role=\"listitem\"><span class=\"vas-article-lesson__number\">02<\/span><\/p>\n<h3>Compare the Pump and System Curves<\/h3>\n<p>The system curve rises as flow increases because pipe and equipment losses grow. The pump head curve normally falls as flow increases. Their intersection is the expected operating point for that pump in that system.<\/p>\n<details>\n<summary>Key points <span>3<\/span><\/summary>\n<ul>\n<li>Do not compare pumps using maximum flow or shut-off head alone<\/li>\n<li>Use the manufacturer\u2019s curve for the actual speed, impeller diameter, and liquid<\/li>\n<li>Check motor power and available net positive suction head across the operating range<\/li>\n<\/ul>\n<\/details>\n<\/article>\n<article class=\"vas-article-lesson\" role=\"listitem\"><span class=\"vas-article-lesson__number\">03<\/span><\/p>\n<h3>Understand the Best Efficiency Point<\/h3>\n<p>The BEP shown in the picture is the point of best hydraulic efficiency on the pump curve. A good selection places the required duty within the manufacturer\u2019s preferred operating range near that point, not simply anywhere the curves cross.<\/p>\n<details>\n<summary>Key points <span>3<\/span><\/summary>\n<ul>\n<li>Operation far from BEP can increase vibration, internal recirculation, noise, and wear<\/li>\n<li>The permitted range varies by pump design and manufacturer<\/li>\n<li>Variable-speed control changes the pump curve and should be evaluated as part of the system<\/li>\n<\/ul>\n<\/details>\n<\/article>\n<article class=\"vas-article-lesson\" role=\"listitem\"><span class=\"vas-article-lesson__number\">04<\/span><\/p>\n<h3>Avoid Oversizing and Undersizing<\/h3>\n<p>An oversized pump may operate too far left of its BEP, waste energy, require throttling, and experience higher mechanical stress. An undersized pump may run too far right, fail to deliver the required head, overload the motor, or face cavitation risk.<\/p>\n<details>\n<summary>Key points <span>3<\/span><\/summary>\n<ul>\n<li>Oversizing can increase throttling losses, stress, noise, and operating cost<\/li>\n<li>Undersizing can prevent the system from reaching its required duty<\/li>\n<li>Select within the manufacturer\u2019s preferred operating range wherever practical<\/li>\n<\/ul>\n<\/details>\n<\/article>\n<article class=\"vas-article-lesson\" role=\"listitem\"><span class=\"vas-article-lesson__number\">05<\/span><\/p>\n<h3>Complete the Final Checks<\/h3>\n<p>After identifying a hydraulically suitable pump, confirm suction conditions, power supply, motor rating, controls, materials, seals, installation dimensions, noise, maintenance access, spares, and lifecycle cost.<\/p>\n<details>\n<summary>Key points <span>3<\/span><\/summary>\n<ul>\n<li>Verify inlet conditions, power supply, controls, and motor rating<\/li>\n<li>Confirm materials, seals, dimensions, environment, and maintenance access<\/li>\n<li>Consider spare-parts support, energy use, and lifecycle cost before purchase<\/li>\n<\/ul>\n<\/details>\n<\/article>\n<\/div>\n<\/section>\n<\/article>\n<aside class=\"vas-article-next\">\n<p class=\"vas-eyebrow\">Put it into practice<\/p>\n<h2>Discuss the Right Product for Your Needs<\/h2>\n<p>Use this guide as a starting point. Final selection should be confirmed against the actual system conditions and manufacturer specifications.<\/p>\n<div class=\"vas-actions\"><a class=\"vas-button\" href=\"https:\/\/vas.co.th\/?page_id=22\">Contact Us<\/a><a class=\"vas-button vas-button--secondary\" href=\"https:\/\/vas.co.th\/?page_id=7\">View Water Pumps<\/a><\/div>\n<p><a class=\"vas-text-link\" href=\"https:\/\/vas.co.th\/?page_id=9\">Back to the Knowledge Center <span class=\"vas-icon vas-icon--arrow-right \" aria-hidden=\"true\"><\/span><\/a><\/aside>\n<\/div>\n<\/section><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Home\/Knowledge Center\/How to Select a Pump Water Pumps How to Select a Pump Good selection starts with the required duty rather than the motor size or connection diameter alone. Selection guide How to Select the Right Water Pump Use this guide as a starting point. Confirm the duty point and final selection with manufacturer performance&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":9,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_kad_post_transparent":"","_kad_post_title":"hide","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"hide","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"class_list":["post-14","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/pages\/14","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vas.co.th\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=14"}],"version-history":[{"count":1,"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/pages\/14\/revisions"}],"predecessor-version":[{"id":38,"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/pages\/14\/revisions\/38"}],"up":[{"embeddable":true,"href":"https:\/\/vas.co.th\/index.php?rest_route=\/wp\/v2\/pages\/9"}],"wp:attachment":[{"href":"https:\/\/vas.co.th\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}