16. Filter, Regulator & Lubricator

18. The solenoid valve energises and passes air to activate the Air Operated Valve

19. The Air Operated Valve allows air to flow from the main line to the hooks Even when the push-button is released and the solenoid valve de-energises

20. After a set delay, the timer activates and passes air to reset the Air Operated Valve The Air Operated Valve, closes, vents the line and cuts the air to the hooks

22. The manual valve closes and passes air to activate the Air Operated Valve

23. The Air Operated Valve allows air to flow from the main line to the hooks Even when the push-button is released

24. After a set delay, the timer activates and passes air to reset the Air Operated Valve The Air Operated Valve, closes, vents the line and cuts the air to the hooks

26. 8 bar 3 bar

27. 7 bar 3 bar

28. 5 bar 3 bar

29. 5 bar 3 bar The differential pressure switch detects the falling pressure in the air tank.

30. 3 bar 4 bar The contacts close, which causes the compressor to start and begin to refill the air tank .

31. 5 bar 3 bar

32. 6 bar 3 bar

33. 7 bar 3 bar When the air tank is topped up to full pressure, the differential pressure switch detects this.

34. 8 bar 3 bar The contacts open, which causes the compressor to stop.

35. 8 bar 3 bar A non-return valve between the compressor and the air tank stops air from leaking back out from the air tank.

37. Solenoid 1 energises to release left hooks

38. The solenoid remains energised by an electrical timer

39. After a time delay, the solenoid de-energises and the air is vented.

40. To release the other side, solenoid 2 energises.

41. After a time delay, the solenoid de-energises and the air is vented.

42. The manual release passes air to the timer, which then activates the air-operated solenoid

43. When the pneumatic time delay is completed, the air signal to the air operated valve is cut.

44. The return spring inside the air operated valve, closes the valve & cuts the air to the hooks

47. Left & right solenoids are normally open type Main solenoid is energised and passes air through the open solenoids to the hooks

48. Main solenoid is energised and passes air through the open solenoids to the hooks

49. Push-button time delay expires and solenoid de-energises and vents line, causing hooks to lock

50. Push-button time delay expires and solenoid de-energises and vents line, causing hooks to lock

51. To release ‘blue’ side only, solenoid ‘R’ is energised which closes the flow to hooks on the ‘red’ side.

52. The main solenoid is energised and air flows to the hooks on the ‘blue’ side only.

63. 2 bar 2 bar A serious air leak will cause pressure in the main cylinders to fall below 3 bar.

64. 2 bar 2 bar Below around 2 bar there is not enough pressure for the pneumatic timer to activate and reset the system

65. 2 bar 2 bar Therefore the hooks will remain open and the leak will prevent the cylinder pressure from rising, despite the operation of the compressor