supply of air brake pipe 20mm with socket & flansg , air brake pipe 20mm with socket & flansge (special) to rdsos drg no wd-80007-s- 11 alt 12 or latest, item no.8, 15 to 18 and confirming to str no.04-abr-02 with all amendmen ts. the specification of 20 nb pipe to specn. astm-a-312 sch.40s gr.tp.304 (erw) as per rdso spe cn. of 04-abr-02 with amendment no.8 of sept 2016 [ warranty period: 30 months after the date of delivery ] ] , pipe 20 mm n.b. with socket & flange as per rdso drg no. wd-80007-s-11, alt-12 or latest, item no. 7 fitted with item no 15 & 16 and confirming to str no. 04-abr-2019 (rev-2 of dec -2019) or latest [ warranty period: 30 months after the date of delivery ] ] , pipe 20 n.b. with socket & flange. drawing no.: rdso,s drg. no. wd-80007-s-11, alt. 12 , ite m no. 5 or latest fitted with item nos. 15 & 16 . material and specification : as per drawing and conformi ng to rdsos spec. no. 04- abr- 2019 (rev 02 of dec 2019). [ warranty period: 30 months after the date of delivery ] ]