Interesting excavator mod

[icestationzebra]

Sounds kinda like the emegency shutoff's on oxy and asetalin (sp?). If the hose is cut or breaks off at the torch it automaticly one time slams shut and stops the flow of gas. Just hope the disigner remember to and that into the build.

Very common with many lifting machines - man lifts, telehandlers, hydraulic cranes, etc. Generally they either use a counterbalance valve or a pilot operated check valve. One valve is used to control one direction (extend or retract), but they are often used in pairs so both directions are protected. In either case you need pressure on both sides of the piston to allow oil out. PO check just needs X pressure to open (opening pressure can be custom ordered), but the CB valves work on a ratio like 60:40.

ISZ

[buckfever]

Very common with many lifting machines - man lifts, telehandlers, hydraulic cranes, etc. Generally they either use a counterbalance valve or a pilot operated check valve. One valve is used to control one direction (extend or retract), but they are often used in pairs so both directions are protected. In either case you need pressure on both sides of the piston to allow oil out. PO check just needs X pressure to open (opening pressure can be custom ordered), but the CB valves work on a ratio like 60:40.

ISZ

Now that makes sense. Might not be a bad thing to have something like that on a boom lift cylinder. There have been a few times were I was setting a beam or manhole and thought this would get ugly if a line blows.