2.4 Flexible pipe 3.6 Non-return valve (flap), straight screw down 2.5 Expansion pipe (corrugated) general 3.7 Non-return valve (flap), angle, screw down 2.6 Joint, screwed 3.8 Safety valve 2.7 Joint, flanged 3.9 Angle safety valve 2.8 Joint, sleeve 3.10 Self-closing valve 2.9 Joint, quick-releasing 3.11 Quick-opening valve
