McElroy Discussion Forums

I have witnessed a lot of premature gland wear on T630/900 over the last few years. Although this may have some other reasons I have found that the improper use of pipe stands/ supports can contribute to some of it. This along with the use of the pipe lifts to assist with pipe line up where the lift is left in contact with the pipe while the carriage is moving. We have tried to provide a cut away depiction of what is happening internally to the main carriage cylinders when this is done. The top drawing is when the machine is allowed to move freely with no ‘racking’. The lower picture is what happens when the cylinders are being ‘racked’. Notice that the piston has become a fulcrum allowing the seals located in the glands to become depressed to the point where the brass touches the rod. When you apply hydraulic pressure to the point where it can overcome the friction it will slide the brass on the rod. To the operator, some of the outward signs of this is a carriage that shudders while moving as well as a fine deposit of brass dust located around the wiper seals.
I hope this can help with the understanding why the use of proper supports and set up is important to the longevity of your equipment

Thanks for a great explanation Dave!

One of the things we try to tell our guys to watch is drag pressure. If you're doing a bunch of the same lengths of pipe and the drag pressure is changing much, you should look at how the pipe is sitting in the machine before closing the jaws and clamps. Sometimes it's as simple as rigging the new piece pipe the same way every time before setting it in the machine.

R

Good post. We also see a lot of cylinders with premature wear due to improper support/alignment of the pipe.

max wear 2.5065 is what I use

I've also noticed massive wear in a 1236 unit here in México regarding this issue, when I first saw it I attributed the wear to a lack of lubrication, but I think Dave here has a point, also I think the owner of the machine doesn't have pipe stands. I'll attach some pictures of the wear. Let me know what you think of it.

_________________
Alexandros Paleologos
McElroy Technician
G&G México
apaleologos@geoygeo.com.mx

It is hard to tell for sure from the pictures but it does look like there is some misalignment of the carriage causing the glands to rub against the guide rods. That is pretty much always the cause of that kind of wear.