supply of twin tower heatless regenerative , supply of twin tower heatless regenerative type air dryer to rdso/spe cn.n o.mp.0.01.00.06 (rev.05) march 2011 (hhp-dmu) except clause no.7.3 and 7.7 as per rdso ap proved model no,orifice size and qap. the firm shall submit a copy of the approval lett er of rdso mentioning the appr oved model no.orifice size and qap. the inter connectin g pipes as per clause 4.13 of the specification mentioned above shall be in the scope of i cf. the item should be procured only from rdso approv ed sources. *the flange connec tion of inlet and outlet pipes should be 1 1/4 bsp a s per rdso drg no-sk dp 3566(annexu re-4 of the governing specification )firm shall include the following ,suitably by embo ssing /engraving o n the name plate 1) model no- 2)orifice size 3)coach application :hhp- dmu. [ warranty period: 30 months after the date of delivery ] ]