52wrench
Well-known member
Very simple, no mechanical ladder type locking system req'd. You need a check valve, ball valve , a couple Tees, a couple 90's and maybe a short section of hose or two for each side. You come out of the fitting on the cylinder into a tee, then on the straight run you put the check valve with the flow towards the cyl obviously then another tee, between the two tee branches you plumb the ball valve. The quick disconnect goes on to the tee. When lifting the ball valves are closed then to lower open the ball valves to bypass the fluid around the check. Any hose failure while lifting closes the check valve and locks the cylinder in position.
I haven't spec'd all the fittings yet and determined the best way to plumb it together to make it compact but it will be a combo of NPT and SAE ends on the fittings to allow the ball valve to be positioned like you want it. Doesn't help with a catastrophic failure of a cylinder seal but the chances of that happening are tiny. The types of lifts that use cables and pulleys can't use this type of system because it won't help if a cable snaps. This is simply a load locking system similar to what is used on heavy equipment. From the Surplus Center:
1/2" NPT 18 GPM CHECK VALVE 5 PSI CRACKING
Item Number: 9-7933-8-5
1/2" NPT CARBON STEEL 7250 PSI BALL VALVE
Item Number: 9-7281-8
I haven't spec'd all the fittings yet and determined the best way to plumb it together to make it compact but it will be a combo of NPT and SAE ends on the fittings to allow the ball valve to be positioned like you want it. Doesn't help with a catastrophic failure of a cylinder seal but the chances of that happening are tiny. The types of lifts that use cables and pulleys can't use this type of system because it won't help if a cable snaps. This is simply a load locking system similar to what is used on heavy equipment. From the Surplus Center:
1/2" NPT 18 GPM CHECK VALVE 5 PSI CRACKING
Item Number: 9-7933-8-5
1/2" NPT CARBON STEEL 7250 PSI BALL VALVE
Item Number: 9-7281-8