{"id":9873,"date":"2026-02-24T15:11:46","date_gmt":"2026-02-24T07:11:46","guid":{"rendered":"https:\/\/www.packqc.com\/standard\/astm-d4991-2\/"},"modified":"2026-03-12T11:03:27","modified_gmt":"2026-03-12T03:03:27","slug":"astm-d4991","status":"publish","type":"standard","link":"https:\/\/www.packqc.com\/lt\/standard\/astm-d4991\/","title":{"rendered":"ASTM D4991"},"content":{"rendered":"<h2 class=\"wp-block-heading\">Kod\u0117l ASTM D4991 yra labai svarbus transporto saugai<\/h2>\n\n\n\n<p>ASTM D4991 standarte daugiausia d\u0117mesio skiriama tu\u0161\u010di\u0173 stand\u017ei\u0173 konteineri\u0173, veikiam\u0173 vakuumo s\u0105lygomis, kurios imituoja sl\u0117gio skirtumus, susidaran\u010dius ve\u017eant oro transportu, vertinimui. Tokios s\u0105lygos da\u017enai susidaro, kai konteineriai i\u0161 \u017eem\u0117s lygio perkeliami \u012f didel\u012f auk\u0161t\u012f, kur suma\u017e\u0117j\u0119s i\u0161orinis sl\u0117gis gali b\u016bti nepalankus sandarikliams ir u\u017edarymo \u012ftaisams.<\/p>\n\n\n\n<p>Standartas padeda laikytis tarptautini\u0173 transporto taisykli\u0173, pavyzd\u017eiui, JT rekomendacij\u0173 d\u0117l pavojing\u0173 krovini\u0173 ve\u017eimo ir ICAO technini\u0173 instrukcij\u0173. Vadovaudamiesi ASTM D4991 standartu, gamintojai ir bandym\u0173 laboratorijos gali nustatyti sl\u0117gio lyg\u012f, kuriam esant prasideda nuot\u0117kis, ir taip u\u017ekirsti keli\u0105 pavojing\u0173 skys\u010di\u0173 i\u0161siliejimui, u\u017eter\u0161imui ar pakuot\u0117s gedimui ve\u017eimo metu.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Standartas ASTM D4991, stand\u017ei\u0173j\u0173 talpykl\u0173 sandarumo bandymai ir vientisumo kontrol\u0117<\/h2>\n\n\n\n<p>ASTM D4991 atlieka svarb\u0173 vaidmen\u012f <strong data-start=\"1954\" data-end=\"1983\">stand\u017eios talpyklos vientisumas<\/strong> tikrinimas naudojant vizualin\u012f ir spaudimu pagr\u012fst\u0105 metod\u0105. Bandymas grind\u017eiamas kontroliuojamu vakuumo taikymu, kai talpyklos yra panardintos \u012f skaidri\u0105 skys\u010dio terp\u0119, tod\u0117l nesandarum\u0105 lengva aptikti.<\/p>\n\n\n\n<p>Pagrindin\u0117s \u0161io metodo savyb\u0117s:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p data-start=\"2236\" data-end=\"2285\">N\u0117ra joki\u0173 konteineri\u0173 u\u017edarymo ar korpuso pakeitim\u0173<\/p><\/li>\n\n\n\n<li><p data-start=\"2236\" data-end=\"2285\"><span style=\"font-size: 1rem;\">Ai\u0161kus vizualus nuot\u0117kio identifikavimas per burbuliukus<\/span><\/p><\/li>\n\n\n\n<li><p data-start=\"2236\" data-end=\"2285\"><span style=\"font-size: 1rem;\">Galima naudoti daugelyje kiet\u0173j\u0173 plastikini\u0173 ir kompozitini\u0173 talpykl\u0173<\/span><\/p><\/li>\n<\/ul>\n\n\n\n<p>Skirtingai nuo lanks\u010di\u0173 pakuo\u010di\u0173 bandym\u0173, ASTM D4991 standartas skirtas stand\u017eioms pakuot\u0117ms ir nustato nuot\u0117kio prad\u017ei\u0105 iki ma\u017edaug 95 kPa sl\u0117gio skirtumo. D\u0117l to jis ypa\u010d vertingas aviacijos logistikoje naudojamiems konteineriams.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Burbulinio nuot\u0117kio bandymo metodas ir vakuuminio nuot\u0117kio aptikimo principas<\/h2>\n\n\n\n<p>The <strong data-start=\"2708\" data-end=\"2735\">burbul\u0173 nuot\u0117kio bandymo metodas<\/strong> pagal ASTM D4991 standart\u0105 naudojamas panardinimas ir <strong data-start=\"2779\" data-end=\"2804\">vakuuminio nuot\u0117kio aptikimas<\/strong> atskleisti defektus, kurie gali nepasireik\u0161ti \u012fprastomis atmosferos s\u0105lygomis. Padid\u0117jus vakuumo sl\u0117giui, nesandarioje talpykloje \u012fkalintas oras i\u0161tr\u016bksta pro defektus, tod\u0117l susidaro nenutr\u016bkstamas burbuliuk\u0173 srautas.<\/p>\n\n\n\n<p>\u0160is metodas turi kelet\u0105 privalum\u0173:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p data-start=\"3061\" data-end=\"3104\"><strong data-start=\"3061\" data-end=\"3091\">Tiesioginis vizualinis patvirtinimas<\/strong> nuot\u0117kio<\/p><\/li>\n\n\n\n<li><p data-start=\"3061\" data-end=\"3104\"><span style=\"font-size: 1rem;\">Ai\u0161kiai atskirti \u012fstrigusius oro burbuliukus nuo tikr\u0173 nuot\u0117ki\u0173<\/span><\/p><\/li>\n\n\n\n<li><p data-start=\"3061\" data-end=\"3104\">Patikimas sandarinimo ar u\u017edarymo tr\u016bkum\u0173 nustatymas<\/p><\/li>\n<\/ul>\n\n\n\n<p>Kadangi bandymo kamera yra skaidri, inspektoriai gali vienu metu steb\u0117ti kelis bandinius ir tuo pat metu ai\u0161kiai matyti kiekvien\u0105 u\u017edarymo srit\u012f.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u017dingsnis po \u017eingsnio bandymo proced\u016bra pagal ASTM D4991<\/h2>\n\n\n\n<p>Nor\u0117damos gauti tikslius ir pakartojamus rezultatus, laboratorijos tur\u0117t\u0173 laikytis strukt\u016brizuotos proced\u016bros, suderintos su ASTM D4991 standartu:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><p data-start=\"3563\" data-end=\"3748\"><strong data-start=\"3563\" data-end=\"3585\">Bandinio panardinimas<\/strong><br>\u012e skaidri\u0105 vakuumin\u0119 kamer\u0105 \u012f etilenglikolio ir vandens tirpal\u0105 \u012fd\u0117kite tu\u0161\u010dias stand\u017eias talpyklas. \u0160velniai mai\u0161ydami pa\u0161alinkite pavir\u0161inius oro burbuliukus.<\/p><\/li>\n\n\n\n<li><strong>Kameros sandarinimas<br><\/strong>Tvirtai u\u017edarykite kameros dangt\u012f. Atidarykite \u012fleidimo vo\u017etuv\u0105 ir \u012fsitikinkite, kad i\u0161leidimo vo\u017etuvas lieka u\u017edarytas, kad pasiruo\u0161tum\u0117te kontroliuojamam vakuumo taikymui.<\/li>\n\n\n\n<li><p data-start=\"3563\" data-end=\"3748\"><\/p><p data-start=\"3563\" data-end=\"3748\"><\/p><p data-start=\"3924\" data-end=\"4090\"><strong data-start=\"3924\" data-end=\"3946\">Vakuuminis taikymas<\/strong><br>Palaipsniui didinkite vakuum\u0105 iki nurodyto sl\u0117gio skirtumo, t. y. iki 95 kPa. Atid\u017eiai kontroliuokite greit\u012f, kad i\u0161vengtum\u0117te klaiding\u0173 parodym\u0173.<\/p><\/li>\n\n\n\n<li><p data-start=\"4095\" data-end=\"4301\"><strong data-start=\"4095\" data-end=\"4115\">Nuot\u0117kio steb\u0117jimas<\/strong><br>Steb\u0117kite talpyklas vakuumo didinimo ir laikymo metu. Nuolatinis arba pasikartojantis burbuliuk\u0173 srautas rodo nuot\u0117k\u012f, o pavieniai burbuliukai paprastai atsiranda d\u0117l \u012fstrigusio oro.<\/p><\/li>\n\n\n\n<li><p data-start=\"4306\" data-end=\"4464\"><strong data-start=\"4306\" data-end=\"4331\">Vakuumo i\u0161laikymo laikotarpis<\/strong><br>Palaikykite vakuum\u0105 bent 10 minu\u010di\u0173. Plastikin\u0117ms vienkartin\u0117ms arba kombinuotoms pakuot\u0117ms laikymo laik\u0105 prat\u0119skite iki 30 minu\u010di\u0173.<\/p><\/li>\n\n\n\n<li><p data-start=\"4469\" data-end=\"4670\"><strong data-start=\"4469\" data-end=\"4504\">Sl\u0117gio i\u0161leidimas ir tikrinimas<\/strong><br>L\u0117tai atleiskite vakuum\u0105 ir palaikykite bandinius panardintus bent 30 sekund\u017ei\u0173 esant aplinkos sl\u0117giui. I\u0161imkite talpyklas ir ap\u017ei\u016br\u0117kite, ar \u012f j\u0173 vid\u0173 nepateko skys\u010dio.<\/p><\/li>\n<\/ol>\n\n\n\n<p>\u0160is sistemingas procesas u\u017etikrina nuoseklius rezultatus ir atitinka reguliavimo l\u016bkes\u010dius.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">ASTM D4991 bandym\u0173 palaikymas naudojant patikim\u0105 \u012frang\u0105<\/h2>\n\n\n\n<p>Tikslus ASTM D4991 standarto vykdymas priklauso nuo stabilios vakuumo kontrol\u0117s, ai\u0161kaus steb\u0117jimo ir nuoseklaus sl\u0117gio reguliavimo. Profesionalus <strong data-start=\"5646\" data-end=\"5678\">L\u0105steli\u0173 instrumentai<a href=\"https:\/\/www.packqc.com\/lt\/product\/lt-03-bubble-leak-test-equipment\/\"> Nuot\u0117kio testeris<\/a><\/strong> pasi\u017eymi tiksliu vakuumo reguliavimu, skaidriomis bandym\u0173 kameromis ir patogiu valdymu, padedan\u010diu laboratorijose atlikti pakartojamus stand\u017ei\u0173j\u0173 talpykl\u0173 sandarumo bandymus.<\/p>\n\n\n\n<p>Tokios sistemos padeda laboratorijoms efektyviai taikyti burbulinio nuot\u0117kio bandymo metod\u0105, kartu u\u017etikrinant duomen\u0173 kokyb\u0119 ir bandym\u0173 nuoseklum\u0105.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">I\u0161vada<\/h2>\n\n\n\n<p>ASTM D4991 nustato ai\u0161ki\u0105 ir veiksming\u0105 sistem\u0105, skirt\u0105 stand\u017ei\u0173j\u0173 talpykl\u0173 nesandarumui vertinti imituojamomis oro transporto s\u0105lygomis. Standartas, kuriame vakuuminis nuot\u0117kio aptikimas derinamas su vizualiniu burbul\u0173 steb\u0117jimu, leid\u017eia laboratorijoms nustatyti nuot\u0117kio rizik\u0105 dar prie\u0161 konteineriams patenkant \u012f lauk\u0105. Kartu su patikima bandym\u0173 \u012franga ir disciplinuotomis proced\u016bromis ASTM D4991 tampa galinga priemone, u\u017etikrinan\u010dia stand\u017ei\u0173j\u0173 konteineri\u0173 vientisum\u0105, atitikt\u012f teis\u0117s akt\u0173 reikalavimams ir saug\u0173 ve\u017eim\u0105 visame pasaulyje.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">DUK<\/h2>\n\n\n\n<p>Kokie sl\u0117gio lygiai taikomi atliekant ASTM D4991 bandymus?<br>Pagal ASTM D4991 paprastai vertinamas nuot\u0117kis iki ma\u017edaug <strong data-start=\"1582\" data-end=\"1603\">95 kPa (13,8 psi)<\/strong>. \u0160is diapazonas imituoja sl\u0117gio poky\u010dius, kurie paprastai patiriami gabenant oro transportu.<\/p>\n\n\n\n<p>Kaip bandymo metu nustatomas nuot\u0117kis?<br>Nutek\u0117jim\u0105 rodo <strong data-start=\"1767\" data-end=\"1812\">nenutr\u016bkstamas arba pasikartojantis burbul\u0173 srautas<\/strong> i\u0161b\u0117gti i\u0161 talpyklos vakuumo taikymo metu arba d\u0117l skys\u010dio, esan\u010dio talpyklos viduje po to, kai vakuumas i\u0161leid\u017eiamas. Pavieniai burbuliukai, susidar\u0119 d\u0117l \u012fstrigusio oro, nelaikomi nuot\u0117kio \u012frodymu.<\/p>\n\n\n\n<p>Kiek m\u0117gini\u0173 reikia bandymams pagal ASTM D4991 atlikti?<br>Jei nenurodyta kitaip, standarte rekomenduojama atlikti bandymus <strong data-start=\"2147\" data-end=\"2190\">bent trys tipi\u0161ki pavyzd\u017eiai.<\/strong>. Keli\u0173 m\u0117gini\u0173 naudojimas padidina rezultat\u0173 patikimum\u0105 ir padeda priimti kokyb\u0117s kontrol\u0117s sprendimus.<\/p>\n\n\n\n<p><a tabindex=\"0\">Galima <\/a><a href=\"https:\/\/store.astm.org\/d4991-25.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">ASTM D4991<\/a> u\u017etikrinti atitikt\u012f teis\u0117s akt\u0173 reikalavimams?<br>Taip. ASTM D4991 da\u017eniausiai naudojamas siekiant u\u017etikrinti atitikt\u012f tarptautin\u0117ms taisykl\u0117ms, pvz. <strong data-start=\"2436\" data-end=\"2467\">ICAO technin\u0117s instrukcijos<\/strong> ir <strong data-start=\"2472\" data-end=\"2530\">JT rekomendacijos d\u0117l pavojing\u0173 krovini\u0173 ve\u017eimo<\/strong>, ypa\u010d stand\u017eioms talpykloms, kuriomis skys\u010diai gabenami oru.<\/p>","protected":false},"featured_media":8781,"parent":0,"template":"","meta":{"_acf_changed":true,"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":"set","ast-page-background-enabled":"default","ast-page-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-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-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-gradient":""}},"ast-content-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-gradient":""},"tablet":{"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-gradient":""},"mobile":{"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-gradient":""}}},"class_list":["post-9873","standard","type-standard","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/standard\/9873","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/standard"}],"about":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/types\/standard"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/media\/8781"}],"wp:attachment":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/media?parent=9873"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}