Hi Everyone, it's Adel from the LIFCO content team! We previously uploaded a video where our mechanic Lloyd tackles a Danfoss piston pump that came off a tunnel-boring machine. The customer states that they couldn't build enough pressure. Although they believe the problem is with the pressure compensator, the compensator seems completely stuck with Loctite. We eventually removed this video from youtube. I sat down with Fraser, owner of Lifco, to talk about what happened.
Adel: You took a video down on Danfoss piston pump. Why?
Fraser: It made us look bad because there was a very obvious solution (or so people thought) that was not addressed at the start of the video. So it looked like we missed that very obvious solution.
Adel: What was missed?
Fraser: A set screw inside the compensator that stops someone from changing the control setting. It was not missed, but Lloyd had loosened it without saying anything. It being a Danfoss I was not familiar with it, or else I would’ve said right from the get go “Hey we loosened the set screw and still can’t get it to adjust”. To make matters worse, I responded to comments without knowing about it.
Adel: Why were you trying to adjust the compensator/control?
Fraser: The customer had bought the machine (A tunnel boring machine) 2nd hand and this pump was cutting off the flow at 2000 psi system pressure. They needed it at 3000 psi but couldn’t adjust it.
Adel: What was ultimately the problem?
Fraser: Likely the threads on the adjustment mechanism were red loctited as an anti-tampering measure (stop operators from adjusting it). It was not budging even after being torched and set screws removed entirely. The threads need to be heated to at latest 250 C (550 F) for it to release.
Adel: What was ultimately the solution?
Fraser: It was such a small inexpensive unit, already worn out. Plus would need more test bench time once the compensator is replaced. So cheaper to just replace the unit.
Adel: Can’t you make a video on the mistake?
Fraser: I think the content was weak. I didn’t like it that it was on a competing product line either. Parker and Linde, that’s what we do best. But I did appreciate the comments. And we are using it as content in our new "Youtube Community".