Mobile crane drawing Mobile crane drawing Rob47 (Industrial) (OP) 26 Nov 17 20:58 See red arrow. Anyone know what the symbol is. The component is connected to a block valve. The drawing is from an mobile crane my friend bought second hand a few weeks ago. The first owner lost part of the manual. http://files.engineering.com/getfile.aspx?folder=412aebe1-b769-48f4-82e6-32 RE: Mobile crane drawing MikeHalloran (Mechanical) 26 Nov 17 21:26 The symbol represents a reservoir or sump, in a more or less standard way. The incomplete rectangle marked 160l is a nonstandard way to show a reservoir. They may, or may not, be the same physical reservoir. The phantom line around the block valve and second reservoir may suggest that 'CE' is some kind of option. The system appears to be an open center system, where the pump runs continuously at full output, and its flow is diverted to the various functions as they are needed. The 3 port valve at lower left blocks all mechanisms for transport. I'm not sure how the 'CE' block interacts with that, perhaps to drain the system? Mike Halloran Pembroke Pines, FL, USA RE: Mobile crane drawing Rob47 (Industrial) (OP) 26 Nov 17 21:39 Many thanks for the info Mike. The 3 port valve at lower left block is to select extend/retract of outrigger beams of the mobile crane or for crane use. RE: Mobile crane drawing MikeHalloran (Mechanical) 26 Nov 17 21:53 Ah. In that case, the 'CE' block may be what allows retraction of the outriggers, assumed spring loaded. Mike Halloran Pembroke Pines, FL, USA RE: Mobile crane drawing Rob47 (Industrial) (OP) 27 Nov 17 04:03 Hi Mike, i figured it out. As you said, the symbol in the CE block is a sump or reservoir. The 160l reservoir and the reservoir in the CE block are physically the same. You were right. The solenoid valve in the CE block diverts the hydraulic oil to tank when all the DC valves in the valve block are in the middle position. That way the oil does not warm up as a result of continuously passing through the DC valve block. Many thanks for your help.