{"id":191,"date":"2024-12-02T00:15:00","date_gmt":"2024-12-02T00:15:00","guid":{"rendered":"https:\/\/pwhtsolutions.net\/?p=191"},"modified":"2024-12-02T00:15:00","modified_gmt":"2024-12-02T00:15:00","slug":"pozadavky-na-tepelne-zpracovani-po-svarovani-pwht","status":"publish","type":"post","link":"http:\/\/pwhtsolutions.net\/cs\/post-weld-heat-treatment-pwht-requirements\/","title":{"rendered":"Po\u017eadavky na tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT)"},"content":{"rendered":"

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT) p\u0159i sva\u0159ov\u00e1n\u00ed trubek je vy\u017eadov\u00e1no, pokud tlou\u0161\u0165ka sva\u0159ovan\u00e9ho materi\u00e1lu p\u0159esahuje stanovenou hodnotu, a\u010dkoli jeho p\u0159esn\u00e9 teploty z\u00e1vis\u00ed na chemick\u00e9m slo\u017een\u00ed materi\u00e1lu a jsou stanoveny v tabulce 331.1.1 p\u0159edpisu ASME B31.3.<\/p>\n

Odd\u00edl VIII obsahuje n\u011bkolik p\u0159\u00edloh, kter\u00e9 obsahuj\u00ed povinn\u00e1 i nepovinn\u00e1 pravidla.<\/p>\n

\u017d\u00edh\u00e1n\u00ed<\/h2>\n

Proces \u017e\u00edh\u00e1n\u00ed se pou\u017e\u00edv\u00e1 ke zm\u011bn\u011b fyzik\u00e1ln\u00edch vlastnost\u00ed kov\u016f a slitin, v\u010detn\u011b uvoln\u011bn\u00ed vnit\u0159n\u00edch pnut\u00ed, zv\u00fd\u0161en\u00ed ta\u017enosti, hou\u017eevnatosti a homogenity, sn\u00ed\u017een\u00ed rizika vzniku trhlin a zlep\u0161en\u00ed odolnosti proti korozi. \u017d\u00edh\u00e1n\u00ed zahrnuje zah\u0159\u00edv\u00e1n\u00ed a n\u00e1sledn\u00e9 ochlazov\u00e1n\u00ed materi\u00e1lu p\u0159i \u0159\u00edzen\u00fdch rychlostech; teplota a rychlost ochlazov\u00e1n\u00ed maj\u00ed vliv na f\u00e1zov\u00e9 slo\u017een\u00ed a strukturu zrn i na rozlo\u017een\u00ed r\u016fzn\u00fdch f\u00e1z\u00ed, jako je austenit nebo ferit, kter\u00e9 ovliv\u0148uj\u00ed mechanick\u00e9 vlastnosti.<\/p>\n

Odd\u00edl VIII divize I ASME je p\u0159\u00edlohou, kter\u00e1 obsahuje povinn\u00e9 a nepovinn\u00e9 p\u0159\u00edlohy, kter\u00e9 obsahuj\u00ed krit\u00e9ria pro navrhov\u00e1n\u00ed, metody nedestruktivn\u00edho zkou\u0161en\u00ed a normy pro p\u0159ej\u00edm\u00e1n\u00ed kontrol tlakov\u00fdch n\u00e1dob. A\u010dkoli je tato norma \u010dasto slo\u017eit\u00e1 a obt\u00ed\u017en\u011b srozumiteln\u00e1, Integripedia nab\u00edz\u00ed stru\u010dn\u00fd a z\u00e1rove\u0148 zjednodu\u0161en\u00fd v\u00fdklad t\u00e9to v\u00fdznamn\u00e9 technick\u00e9 normy, p\u0159i\u010dem\u017e podrobn\u011b popisuje jej\u00ed historii, z\u00e1sady a praktick\u00e9 aplikace.<\/p>\n

Divize 3 stanov\u00ed pravidla, kter\u00e1 se vztahuj\u00ed na tlakov\u00e9 n\u00e1doby pracuj\u00edc\u00ed p\u0159i vnit\u0159n\u00edm nebo vn\u011bj\u0161\u00edm provozn\u00edm tlaku nejm\u00e9n\u011b 10 000 psi, co\u017e je p\u0159\u00edsn\u011bj\u0161\u00ed ne\u017e v divizi 1. Tento odd\u00edl umo\u017e\u0148uje vy\u0161\u0161\u00ed hodnoty intenzity nap\u011bt\u00ed ne\u017e divize 1 a z\u00e1rove\u0148 nasti\u0148uje po\u017eadavky na tlakov\u00e9 n\u00e1doby pro lidi, kter\u00e9 se pou\u017e\u00edvaj\u00ed p\u0159edev\u0161\u00edm v pot\u00e1p\u011b\u010dsk\u00e9m pr\u016fmyslu. Znalost v\u0161ech t\u0159\u00ed diviz\u00ed odd\u00edlu VIII ASME v\u00e1m umo\u017en\u00ed \u010dinit lep\u0161\u00ed obchodn\u00ed rozhodnut\u00ed.<\/p>\n

Normalizace<\/h2>\n

Norma ASME, odd\u00edl VIII, divize 1 stanov\u00ed pravidla a pokyny pro navrhov\u00e1n\u00ed, v\u00fdrobu, kontrolu a zkou\u0161en\u00ed tlakov\u00fdch n\u00e1dob pracuj\u00edc\u00edch s vnit\u0159n\u00edm nebo vn\u011bj\u0161\u00edm tlakem vy\u0161\u0161\u00edm ne\u017e 15 psig. Tato norma pokr\u00fdv\u00e1 mnoho pr\u016fmyslov\u00fdch odv\u011btv\u00ed a aplikac\u00ed - v\u010detn\u011b t\u011b\u017eby ropy a plynu, zpracov\u00e1n\u00ed chemik\u00e1li\u00ed a v\u00fdroby energie - a z\u00e1rove\u0148 nab\u00edz\u00ed jasn\u00e9 pokyny pro vytv\u00e1\u0159en\u00ed, kontrolu a certifikaci t\u011bchto tlakov\u00fdch n\u00e1dob, aby byla zaru\u010dena jejich bezpe\u010dnost a spolehlivost.<\/p>\n

Tento p\u0159edpis obsahuje vzorce a pravidla, kter\u00e1 vyu\u017e\u00edvaj\u00ed pr\u016fmyslov\u00e9 zku\u0161enosti pro navrhov\u00e1n\u00ed n\u00e1dob a poskytuj\u00ed konzervativn\u011bj\u0161\u00ed pravidla ne\u017e jin\u00e9 odd\u00edly. Tato pravidla zahrnuj\u00ed bezpe\u010dnostn\u00ed faktor 3,5 pro pevnost v tahu a tak\u00e9 zohledn\u011bn\u00ed meze kluzu a teploty. Krom\u011b toho jsou zde rozs\u00e1hl\u00e9 po\u017eadavky na nedestruktivn\u00ed zkou\u0161ky, v\u010detn\u011b radiografick\u00fdch zkou\u0161ek, kontrol magnetick\u00fdch \u010d\u00e1stic a penetra\u010dn\u00edch zkou\u0161ek.<\/p>\n

Normalizace spo\u010d\u00edv\u00e1 v tom, \u017ee se pro ka\u017ed\u00fd materi\u00e1l p\u0159i r\u016fzn\u00fdch teplot\u00e1ch stanov\u00ed p\u0159\u00edmka dovolen\u00e9ho nap\u011bt\u00ed, p\u0159i\u010dem\u017e rozhoduj\u00edc\u00ed je nejni\u017e\u0161\u00ed p\u0159\u00edmka. To umo\u017e\u0148uje v\u011bt\u0161\u00ed flexibilitu p\u0159i konstruk\u010dn\u00edch v\u00fdpo\u010dtech, pou\u017eit\u00ed ten\u010d\u00edch materi\u00e1l\u016f bez zv\u00fd\u0161en\u00ed n\u00e1klad\u016f a z\u00e1rove\u0148 zv\u00fd\u0161en\u00ed konstruk\u010dn\u00edch mo\u017enost\u00ed a flexibility p\u0159i konstruk\u010dn\u00edch v\u00fdpo\u010dtech. Krom\u011b toho existuj\u00ed dal\u0161\u00ed omezen\u00ed t\u00fdkaj\u00edc\u00ed se v\u00fdb\u011bru materi\u00e1l\u016f, po\u017eadavk\u016f na r\u00e1zov\u00e9 zkou\u0161ky, sva\u0159ovac\u00edch postup\u016f, povinn\u00fdch\/nepovinn\u00fdch p\u0159\u00edloh s krit\u00e9rii\/metodikami n\u00e1vrhu\/normami pro p\u0159ej\u00edmku p\u0159i kontrol\u00e1ch a tak\u00e9 pravidel t\u00fdkaj\u00edc\u00edch se pou\u017e\u00edv\u00e1n\u00ed certifika\u010dn\u00edch zna\u010dek U, UM nebo UV ASME pro tlakov\u00e9 n\u00e1doby.<\/p>\n

P\u0159edeh\u0159\u00e1t\u00ed<\/h2>\n

Odd\u00edl VIII divize 1 ASME stanov\u00ed pravidla a p\u0159edpisy pro navrhov\u00e1n\u00ed, v\u00fdrobu, zkou\u0161en\u00ed, inspekci, testov\u00e1n\u00ed a certifikaci tlakov\u00fdch n\u00e1dob. Krom\u011b toho tento p\u0159edpis obsahuje povinn\u00e9 i nepovinn\u00e9 p\u0159\u00edlohy, kter\u00e9 uv\u00e1d\u011bj\u00ed dal\u0161\u00ed konstruk\u010dn\u00ed krit\u00e9ria, techniky nedestruktivn\u00edho zkou\u0161en\u00ed a p\u0159ej\u00edmac\u00ed normy, kter\u00e9 dopl\u0148uj\u00ed standardn\u00ed po\u017eadavky. D\u00e1le tento p\u0159edpis specifikuje po\u017eadavky na n\u011bkolik t\u0159\u00edd materi\u00e1l\u016f pou\u017e\u00edvan\u00fdch ke konstrukci tlakov\u00fdch n\u00e1dob, jako\u017e i metody sva\u0159ov\u00e1n\u00ed\/v\u00fdroby a tak\u00e9 po\u017eadavky na zkou\u0161en\u00ed, postupy certifikace ra\u017een\u00ed v r\u00e1mci kone\u010dn\u00e9 certifikace n\u00e1dob.<\/p>\n

Divize 1 pou\u017e\u00edv\u00e1 pro stanoven\u00ed tlou\u0161\u0165ky n\u00e1dob vzorce a pravidla odvozen\u00e1 z pr\u016fmyslov\u00fdch zku\u0161enost\u00ed, co\u017e v\u0161ak m\u016f\u017ee v\u00e9st k p\u0159\u00edli\u0161 velk\u00fdm n\u00e1dob\u00e1m, kter\u00e9 \u010dasto nevyhovuj\u00ed zam\u00fd\u0161len\u00e9mu pou\u017eit\u00ed. K p\u0159ekon\u00e1n\u00ed tohoto probl\u00e9mu byly vytvo\u0159eny sm\u011brnice PD 5500 a EN 13445, kter\u00e9 konstrukt\u00e9r\u016fm nab\u00edzej\u00ed v\u00edce mo\u017enost\u00ed pro vytv\u00e1\u0159en\u00ed leh\u010d\u00edch n\u00e1dob a v\u00fdm\u011bn\u00edk\u016f.<\/p>\n

Divize 2 se od divize 1 li\u0161\u00ed t\u00edm, \u017ee se navrhuje pomoc\u00ed procesu \u201canal\u00fdzy podle n\u00e1vrhu\u201d, kter\u00fd vy\u017eaduje slo\u017eit\u011bj\u0161\u00ed v\u00fdpo\u010dty a p\u0159\u00edsn\u011bj\u0161\u00ed hodnoty intenzity nap\u011bt\u00ed - d\u00edky tomu je vhodn\u00e1 pro tlakov\u00e9 n\u00e1doby s lidskou pos\u00e1dkou (zejm\u00e9na pro plavidla pot\u00e1p\u011b\u010dsk\u00e9ho pr\u016fmyslu), jako jsou pot\u00e1p\u011b\u010dsk\u00e9 n\u00e1dr\u017ee. Krom\u011b toho mus\u00ed b\u00fdt v divizi 2 dodr\u017eov\u00e1ny p\u0159\u00edsn\u011bj\u0161\u00ed postupy kontroly kvality.<\/p>\n

Hydrotest<\/h2>\n

Hydrotesty jsou hlavn\u00edm prost\u0159edkem ov\u011b\u0159ov\u00e1n\u00ed tlakov\u00e9 \u00fanosnosti a t\u011bsnosti potrubn\u00edch syst\u00e9m\u016f, kter\u00fd spole\u010dnosti pou\u017e\u00edvaj\u00ed k zaji\u0161t\u011bn\u00ed toho, aby jejich za\u0159\u00edzen\u00ed spl\u0148ovala po\u017eadavky p\u0159edpis\u016f a byla bezpe\u010dn\u00e1 pro provoz. Vadn\u00e9 syst\u00e9my mohou zp\u016fsobit zna\u010dn\u00e9 \u0161kody, zran\u011bn\u00ed a dokonce i \u00famrt\u00ed; krom\u011b toho zp\u016fsobuj\u00ed jejich majitel\u016fm dal\u0161\u00ed provozn\u00ed prostoje a n\u00e1klady - a hydrotestov\u00e1n\u00ed poskytuje \u0159e\u0161en\u00ed t\u00edm, \u017ee odhaluje probl\u00e9my d\u0159\u00edve, ne\u017e vzniknou, a p\u0159ij\u00edm\u00e1 opat\u0159en\u00ed k jejich \u0159e\u0161en\u00ed d\u0159\u00edve, ne\u017e dojde k ne\u0161t\u011bst\u00ed.<\/p>\n

Hydrotesty nemus\u00ed v\u017edy poskytnout odpov\u00eddaj\u00edc\u00ed test integrity potrubn\u00edch syst\u00e9m\u016f. Svarov\u00e9 spoje a spoje mohou obsahovat vnit\u0159n\u00ed vady, kter\u00e9 nelze vodou zjistit; selh\u00e1n\u00ed p\u0159i hydrotestech by nav\u00edc mohlo indikovat svary bl\u00edzko bodu nulov\u00e9 ta\u017enosti a p\u0159edstavovat nebezpe\u010dn\u00fd sc\u00e9n\u00e1\u0159 selh\u00e1n\u00ed.<\/p>\n

Tak\u00e9 voda pou\u017e\u00edvan\u00e1 p\u0159i hydrotestov\u00e1n\u00ed m\u016f\u017ee obsahovat kontaminanty, jako jsou chloridy, kter\u00e9 mohou zp\u016fsobit d\u016flkovou korozi nebo korozn\u00ed prask\u00e1n\u00ed v nerezov\u00e9 oceli, co\u017e vy\u017eaduje pneumatick\u00e9 testov\u00e1n\u00ed nam\u00edsto testov\u00e1n\u00ed vodou. Jadern\u00e9 aplikace v\u0161ak vy\u017eaduj\u00ed zkou\u0161en\u00ed vodou; nav\u00edc mus\u00ed b\u00fdt pou\u017eita vysoce kvalitn\u00ed voda, proto\u017ee p\u0159\u00edpadn\u00e1 rizika kontaminace a koroze by jinak byla p\u0159\u00edli\u0161 velk\u00e1; nav\u00edc mus\u00ed b\u00fdt z tohoto zdroje vody p\u0159ed zkou\u0161en\u00edm odstran\u011bn ve\u0161ker\u00fd plynn\u00fd vod\u00edk.<\/p>","protected":false},"excerpt":{"rendered":"

Post-weld heat treatment (PWHT) in pipe welding is required if the weld material exceeds a specified thickness, though its exact temperatures depend on chemical makeup of material and are specified by ASME B31.3 code table 331.1.1. Section VIII provides several appendices which contain both mandatory and non-mandatory rules. Annealing The annealing process is used to … <\/p>\n

P\u0159e\u010dt\u011bte si v\u00edce “Post-Weld Heat Treatment (PWHT) Requirements”<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-191","post","type-post","status-publish","format-standard","hentry","category-pwht-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/comments?post=191"}],"version-history":[{"count":1,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/191\/revisions"}],"predecessor-version":[{"id":192,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/191\/revisions\/192"}],"wp:attachment":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/media?parent=191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/categories?post=191"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/tags?post=191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}