00 Unit 23 Instrumentation and Control Drawings 445 3 EXHAUST MAN MAN T AIR 9 L (12) 2-WAY PUSH-BUTTON VALVE CLIPPARD MJV-2 3) TIMAC AIR TIME DELAY VALVE TIMING RANGE .2-20 SECONDS MAC VAKVES INC. MODEL 71A-2-2 4) AIR CYLINDER AIRMATIC VALVE INC. 5) 4-WAY 5-PORT SPRING RETURN VALVE MILLER FLUID POWER CO. MODEL 504, 1/4 NPT LUB. (67 EXHAUST CONTROL AIRMATIC VALVE INC. OR VERSA PRODUCTS CO. 6 8) SHUT OFF VALVE 9 FILTER-REGULATOR-LUBRICATOR COMBINATION WITH PRESSURE GAUGE. NORGREN FILT. UNIDYNAMICS PHOENIX PHOENIX, ARIZONA A DIVISION OF UMC INDUSTRIES, INC. TOOL NAME PNEUMATIC CIRCUIT FOR DEAD WEIGHT PRESS CODE IDENT NO. DWG (TOOL) NO. 3ZIS B 12079 20-837 Print supplied by Unidynar PH 23-1. Pneumatic Circuit for Dead Weight Press. Copyright Goodheart-Willcox Co., Inc. Refer to print PR 23-1. The sequence of operations for this print is given below. Answer the questions following the sequence of operations Sequence of operations 1. The operator actuates the two push-button valves (1) and (2) until the weight starts to descend. 2. Air passes through valves (1) and (2) to the time delay valve (3) and the pilot of valve (5). 3. The four-way valve (5) is shifted, venting the head end of cylinder (4) and pressurizing the rod end. 4 The weight of the ram descends The speed of descent is controlled by the exhaust control (7). 6. The time delay valve (3) continues to time until the preset interval has passed. 7. The time delay valve (3) vents air pressure from the line between valve (2) and the pilot of valve (5) 8. With the pilot vented, the spring return of valve (5) shifts the valve to its normal position. The rod end of cylinder (4) is vented and the head end is pressurized. 10. The weight ascends. 11. The speed of ascent is controlled by the exhaust control (6). Questions 8. What causes cylinder (4) to reverse? lonexe inh 9. What does the center line around valve (3) indicate? What component(s) are included? 10. Why is it not necessary to hold valves (1) and (2) down during the entire sequence?