Had a 10-year-old hydraulic valve block crack on me during a pressure test yesterday

I was doing a routine annual inspection on a bank elevator in Springfield, and the main valve block just split open when I hit the test pressure, spraying fluid everywhere. I had to shut down the system, clean up a huge mess, and order a whole new assembly from the manufacturer. Has anyone else seen a failure like that on a unit that wasn't even that old?

3 comments

3 Comments

nina1472mo ago

Yeah, "wasn't even that old" got me. I used to think 10 years was solid for a valve block, but I've seen a few fail right around that mark from casting flaws you just can't see. The metal fatigue builds up slow until a pressure test finds the weak spot.

the_emery2mo ago

You're right, @nina147, a good pressure test at year eight can save a lot of trouble later.

shane_wilson29d ago

Does the failing part have a date code stamped anywhere? Sometimes that "10 year old" block was actually sitting on a shelf for a few years before it ever got installed, so the rubber seals and internal stresses started aging way before the system even saw its first pressure cycle. I've pulled rebuilt blocks out of old stock that looked brand new but the date code showed they were from a bad production run in 2012. If your part was cast during a period when the foundry was switching suppliers for their raw billet, you might be looking at a metallurgy issue, not a design or maintenance problem. Worth checking the serial number against any service bulletins too.