W.R. Long valve kit, Piston Blown....Why?

[sixwarden9]

I have a W.R. Long valve kit on a TC 40A attached to a Lion 2" bore X 6" stoke 2500 psi cylinder. The cylinder is on a home built grapple like the ATI bolt on. The whole setup is using 1/4" hoses with a flow restrictor attached to one of the cylinder ports.

The grapple setup has about 3 hrs on it and the W.R. Long valve kit has about an hour of use for a total of 4 hours cylinder use. On Saturday everything was going great and then all of a sudden the grapple was slow to close and then suddenly was stuck open (cylinder fully closed). The valve kit acted like it was stuck open, because there was still pressure on one of the lines. I turned the tractor off and the pressure went away. Tractor back on and the pressure was back. After a few minutes the valve kit was back to normal, but after opening the grapple it bled back down.

Today I hooked the grapple back up to my rear remotes and it did the same thing (bled down), so I took the cylinder apart and found nice shiny chunks of metal. The actual piston had broken on one side and it look like someone cut the O-rings with a knife.

So here are the questions:

Did the cylinder fail as a result of the valve kit possibly being stuck open, i.e. pressure build up?

Or

Did the cylinder fail first causing the valve kit to act funny?

What would cause either?

 

[MadReferee]

I will bet that the cylinder failed first.

It would take a lot of pressure to do that kind of damage to a cylinder and the relief should have activated way before that could have happened. Once the cylinder failed all you were getting was fluid flowing right thru the cylinder.

Who makes that Lion cylinder? I usually use Chief (made in USA by Bailey) or Prince cylinders.

 

[sixwarden9]

Monarch industries makes the cylinder. It is stamped made in Canada. It is the same kind found at TSC and Northern Tool.