Figure   C–3. Vent    Assembly Model     53029A–20 (1) (2) (3) (4) (5) (6) (7) (8) ILLUSTRATION DESCRIPTION QTY (a) (b) NATIONAL INC FIG ITEM SMR STOCK PART IN NO NO CODE NUMBER FSCM NUMBER USABLE  ON  CODE U/M UNIT C-3 Group 02 Vent Assembly C-3 1 49234 EX1333B-2 Cap,    Relief  with  Gasket Ea 1 C-3 2 81718 71OA2X1 Standpipe, 2” nom, Schedule 40 Ea 1 C-3 3 5305-00-225-3839 96906 MS90725-8 Screw,    Hex–hd,  l/4–in. Ea 8 C-3 4 5310-00-809-4058 96906 MS27183-10 Washer,  Flat,  l/4–in. Ea 8 C–3 5 96906 MS27023–21 Flanged   Adaptor Ea 1 C-3 6 5330-00-291-3085 96906 MS29513-250 O-Ring Ea 1 C–3 7 4730-00–649-9100 96906 MS27028–11 Dust  Cap  With  Chain  and  Gas– Ea 1 ket C-3 8 4720-00-649-9103 96906 MS27024–11 Coupling,  Q–D  Female,  2“ Ea 1 C-3 9 5310-00-612-2414 96906 MS27030-6 Gasket,  2“ Ea 1 Change 1 C-7