Lost hot tap coupon in a pipe 1

[seasar]

Had a bit of an oops moment earlier when contractor were performing a hot tap on a glycol line in that the pilot bit broke
off and the coupon dropped into the pipe. The next thing the pipe
does is run 50 ft up. Are there any rules of thumb for velocity
required to carry an object through that situation? If the coupon sits at the bottom of the elbow prior to the run up for eternity I'm happy...and that is what I expect it do based on gut feel but something to confirm that would be nice.

Any advice? Can't imagine I'm the first person in this situation. Thanks!

 

[MiketheEngineer]

Kinda depends on the area, weight and flow volume. Sorry - no help here.

 

[seasar]

As an update...this is 32% propylene glycol at 30F.

 

[Duwe6]

What are the diameters of the "cookie" and the line? Is the cookie SCH40 or 80?

 

[seasar]

2 3/8" Cookie...10" line...sched 40.

Velocity in the line doesn't exceed 3 fps.

My rule of thumb is that the velocity required to lift an object in a situation like this must be greater than the free fall velocity it would experience in a stagnant line.

 

[MiketheEngineer]

At 3 fps - my guess is that it is sitting at the bottom of the elbow and not likely to move.

 

[Duwe6]

Agree with Mike, it will not make it up the 50-ft rise. As seasar points out, the flow velocity has to be similar or larger than the free-fall velocity. You could try an experiment using a 10-ft tall 10-inch riser and a fire hose. Should prove that the cookie will stay near the bottom ell.

 

[cvg]

strap a magnet on the elbow

 

[racookpe1978]

At the elbow, remove the (external) insulation. Put a good-sized magnet on the lower surface of the elbow, and move it back and forth. You might be able to hear the coupon sliding back and forth inside the pipe. That doesn't get it out of the pipe, but it will tell you where it is.

Xrays of the pipe will confirm the location - at a higher price.