Kev piav qhia ntawm Imperial Thread Standards

Raws li cov txheej txheem siv feem ntau hauv kev lag luam tshuab, imperial threads raug faib los ntawm cov duab rau hauv cylindrical threads thiab tapered threads, thiab los ntawm xov kaum rau 55℃Whitworth threads thiab 60℃Unified National Threads. Imperial xov loj cov cim xws li 1/8, 1/4 thiab 1/2 yog ntsuas hauv nti. Raws li kev lag luam conventions, 1 nti sib npaug 8 British fractional division; Piv txwv li, 1/4 nti yog hu ua 2 division thiab 1/2 nti yog hu ua 4 division.

NPT, PT, G thiab RC yog cov qauv kev lag luam hauv cov yeeb nkab xov uas muaj nyob hauv Asmeskas thiab Askiv tus qauv txheej txheem, nrog rau qhov sib txawv hauv kev ua haujlwm, xov xov thiab cov qauv kev sib khi.

1. Kev faib ua kom ntxaws ntawm cov qauv ntawm cov yeeb nkab sib txuas

1.1 NPT Xov

NPT (National Pipe Thread) yog 60℃tapered sealing yeeb nkab xov raws li Asmeskas cov qauv, dav siv rau hydraulic, pneumatic thiab roj sealing pipelines hauv North America. Nws ua raws li lub teb chaws tus qauv GB / T 12716-1991. Featuring self-sealing kev ua tau zoo los ntawm tapered xov extrusion tsis muaj gaskets ntxiv, nws muab kev ruaj ntseg sealing zoo heev.

1.2 PT Xov

PT xov yog 55℃tapered sealing yeeb nkab xov ntawm British Whitworth xov tsev neeg nrog tus qauv taper ntawm 1:16. Nws yog dav siv nyob rau hauv dej, roj thiab siab pipeline systems nyob rau hauv Teb chaws Europe thiab Commonwealth lub teb chaws, ua raws li lub teb chaws tus qauv GB / T 7306-2000. Sealing yog tiav los ntawm compression thiab extrusion thaum lub sij hawm xov kev koom tes.

1.3 G xov

G xov yog ib tug 55℃tsis-sealing cylindrical yeeb nkab xov kuj teej tug mus rau lub Whitworth xov system. Tsis muaj taper, nws tsis tuaj yeem ua tiav nws tus kheej sealing thiab yuav tsum muaj cov khoom siv sib khi xws li gaskets thiab PTFE daim kab xev thaum sib dhos. Nws ua raws li lub teb chaws tus qauv GB / T 7307-2001. Cov cim loj ntawm G threads sawv cev rau cov yeeb nkab nominal nyob rau hauv nti.

1.4 RC thiab ZG Xov Piav Qhia

RC hais txog British 55℃tapered internal sealing yeeb nkab xov. ZG yog ib qho kev tsim khoom siv hauv tsev tsis siv neeg rau cov yeeb nkab txuas, uas tau raug hloov pauv los ntawm kev sib koom ua ke R thiab RC tus qauv series thiab tsis siv ntxiv lawm. Tapered xov qauv saws rau cov yeeb nkab dej thiab hydraulic pob qij txha ua tiav xauv thiab sealing los ntawm tapered nto haum.

2. Kev sib piv qhov loj me thiab cov npe nrov ntawm Standard Imperial Pipe Threads

Imperial thread conversion standard: 1 nti=25.4 hli, 1 nti=8 British fractional divisions

3/4 nti xov: feem ntau hu ua 6 division, sib haum mus rau lub nominal yeeb nkab txoj kab uas hla ntawm kwv yees li 20 hli

1/2 nti xov: feem ntau hu ua 4 division, sib haum mus rau lub nominal yeeb nkab txoj kab uas hla ntawm kwv yees li 15 hli

1 nti xov: feem ntau hu ua 1 nti, sib haum mus rau lub nominal yeeb nkab txoj kab uas hla ntawm kwv yees li 25 hli

1-1/2 nti xov: feem ntau hu ua 1.5 ntiv tes, sib haum rau cov yeeb nkab nominal ntawm kwv yees li 32 hli

DN stands rau nominal txoj kab uas hla, ib tug unified specification cim rau pipeline txuam.

3. Kev ua haujlwm sib txawv ntawm cylindrical thiab tapered yeeb nkab xov

Tapered yeeb nkab threads (NPT, PT, RC) txais tus qauv 1: 16 taper. Cov xov nruj zuj zus thaum lub sij hawm kev koom tes thiab paub txog kev sib khi zoo los ntawm cov xov extrusion thiab deformation, ua rau lawv tsim nyog rau cov txheej txheem siab sealing xws li hydraulic circuits, high-pressure oil pipelines thiab airtight piping systems.

Cylindrical yeeb nkab threads (G threads) yog cov xov ncaj nrog kev ruaj khov clearance thiab tsis muaj peev xwm sealing tus kheej. Lawv feem ntau yog siv rau cov dej tsis tshua muaj siab thiab cov raj xa hluav taws xob sib txuas uas tsom mus rau qhov chaw thiab nrawm, thiab cov khoom siv sib khi yuav tsum tau tiv thaiv kom tsis txhob tawm. Lub ntsiab sib txawv ntawm ob hom yog nyob rau hauv taper qauv thiab sealing mechanism.

4. Lub ntsiab txhais thiab kev faib cov xov

Ib tug xov yog ib tug tas li tsis tu ncua cov hniav profile machined raws ib tug kauv nkhaus nyob rau saum npoo ntawm ib tug cylindrical los yog conical puag. Qhov loj ntawm cov xov yog txhais tau tias yog xov crest, thiab qhov zawj ntawm cov crests uas nyob ib sab yog xov hauv paus. Hauv kev ua tshuab, thaum lub workpiece tig ib lub voj voog tag nrho, lub cuab yeej txav axially los ntawm lub suab ruaj khov los tsim cov qauv xov tiav.

Threads machined rau sab nrauv yog cov xov sab nraud, thaum cov khoom siv rau hauv qhov chaw sab hauv yog cov xov sab hauv. Qhov sib txuam ntawm cov xov sab hauv thiab sab nraud paub txog txhua yam fastening thiab kev sib txuas.

Raws li cov hniav sib tsoo, cov xov tau muab faib ua peb lub voj voos, trapezoidal threads, sawtooth threads, square threads thiab ncig arc threads. Imperial thiab American tus qauv zoo tib yam threads tag nrho yog cov duab peb sab threads, uas yog feem ntau siv xov hom nyob rau hauv txhua yam sib dhos.