Dhumucda derbiga birta ee taxanaha ah waxay ka timid cutubka metrology ee Ingiriiska, iyo dhibcaha waxaa loo isticmaalaa in lagu muujiyo cabbirka.Thedhumucda derbiga eeTuubooyin aan sal lahayn waxay ka samaysan yihiin taxanaha Jadwalka (40, 60, 80, 120) waxayna ku xidhan yihiin taxanaha miisaanka (STD, XS, XXS).Qiimayaashan waxa loo rogaa millimitir ahaan iyada oo qayb ka ah taxanaha dhumucda gidaarka tuubada.(Fiiro gaar ah: Cabbirka - qiimaha Schedule40 ma aha mid joogto ah, laakiin si loo eego dhexroorka dibadda ee tuubada.)

Habka lagu muujinayo dhexroorka tuubada iyo dhumucda, dhexroorka sare ee magaca iyo dhumucda ugu yar ee tuubada dusha kululaynta, NPS ee tuubada tuubada iyo lambarka jadwalka derbiga tuubada.Dhumucdiisuna waxay ka kooban tahay 8 taxane min 10 ilaa 20, 30, 40, 80,120, 140, 160.taxane.

Dhumucda darbiga halbeegga Ameerikaanka iyo heerka gurigu aad buu u kala duwan yahay.Guud ahaan, labada darajo cadaadis ee CL.150 iyo CL.300 ma sarreeyaa.Guud ahaan, SCH10S iyo SCH40 ayaa la isticmaalaa.In ka yar 50 dooro SCH80 iyo SCH40S.

SCH40, nambarka tuubada, haday tahay mid gudaha ah ama haday shisheeye tahay, Sch.XX waxa loo isticmaalaa in lagu muujiyo dhumucda gidaarka tuubada.GB/T81631 HG20553 waxa kale oo lagu daray heerka qaranka GB/T81631 HG20553, iwm., marka loo eego dhexroorka dibadda ee tuubada ama cabbirka tuubada, dhumucda gidaarka ee cabbirrada kala duwan ee lagu tilmaamay tiro isku mid ah tuubooyinka ayaa kala duwan.

Habka lagu muujinayo dhumucda gidaarka ee birta birta ah waxay leedahay saddex hab: cabbirka cabbirka tuubada, cabbirka dhumucda gidaarka birta iyo miisaanka tuubada:

1) Dhumucda gidaarka waxaa lagu muujiyay lambarka tuubada "Sch".
Nambarka cabbirka tuubada waa saamiga cadaadiska naqshadeynta tuubada ilaa cadaadiska la oggol yahay ee walxaha heerkulka naqshadeynta lagu dhufto 1000 oo wareegsan.Magac ahaan: Sch=P/[σ]t×1000
ANSI B36.10 qiimaynta dhumucda gidaarka: Sch10, Sch20, Sch30, Sch40, Sch60, Sch80, Sch100, Sch120, Sch140, Sch160 toban darajo;
ANSI B36.19 darajo dhumucdiisuna waxay tahay: Sch5s, Sch10s, Sch40s, Sch80s afar fasal;

2) Marka loo eego dhumucda darbiga birta birta, Shiinaha, ISO, Japan, qaar ka mid ah heerarka tuubooyinka birta ayaa la qaatay.

3) Dhumucda gidaarka tuubada waxa lagu muujiyaa culayska tuubada, taas oo dhumucda gidaarka tuubada u qaybisa saddex nooc.
a.Tuubada miisaanka caadiga ah, oo lagu muujiyey STD
b tuubo dhumuc weyn, oo lagu muujiyey XS
c.Tuubo qaro weyn, oo uu tilmaamayo XXS.
Tuubooyinka leh DN ≤ 250mm, Sch40 waxay u dhigantaa STD, DN <200mm pipe, Sch80 waxay u dhigantaa XS.