Go Back  CorvetteForum - Chevrolet Corvette Forum Discussion > Off Topic > Off Topic
Reload this Page >

Hydraulic press -- how's this for pressure?

Off Topic Off Topic | Non-Corvette

Hydraulic press -- how's this for pressure?

 
Old 05-16-2019, 03:10 PM
  #1  
VegasJen
CFOT Attention Whore
Support Corvetteforum!
Thread Starter
 
VegasJen's Avatar
 
Member Since: Dec 2001
Location: Press "2" for English
Posts: 28,203
Received 59 Likes on 20 Posts
Default Hydraulic press -- how's this for pressure?

In our laundry, we have washers that discharge linen on average about every three minutes. We can't get enough water out by spinning it for three minutes so we use a hydraulic press to push the water out. Last night when I got in I found that one of the presses had failed. The plate (platen) that bolts to the ram had cracked. Check this out.

That's 3.5" of plate steel. I am stunned there is enough force to do that. We press to about 50bar, or about 725psi. Given the sheer mass of the platen, that is astounding to me. But then again, my rough calculations is this platen has pressed close to a million loads of linen in its service life.
VegasJen is offline  
Old 05-16-2019, 03:11 PM
  #2  
KarlK
CF Senior Member
 
KarlK's Avatar
 
Member Since: Sep 2006
Location: No, I'm not related to PeterK
Posts: 45,020
Received 27 Likes on 16 Posts
Default

been cracked for a looong time, great PM program
KarlK is offline  
Old 05-16-2019, 03:14 PM
  #3  
Der Flieger
CF Senior Member
 
Der Flieger's Avatar
 
Member Since: Oct 2004
Posts: 10,705
Received 18 Likes on 6 Posts
Default

Pink nail polish? I thought you were more a 'purple' gurl.
Der Flieger is offline  
Old 05-16-2019, 03:19 PM
  #4  
DJ_Critterus
CF Senior Member
 
DJ_Critterus's Avatar
 
Member Since: Jan 2006
Location: FL.... America's Wang! No shrinkage. Winter's not coming!
Posts: 51,371
Received 75 Likes on 46 Posts
St. Jude Donor '09
Default

The stress of the job was just too much....
DJ_Critterus is offline  
Old 05-16-2019, 03:21 PM
  #5  
TwoSmoke
CF Senior Member
 
TwoSmoke's Avatar
 
Member Since: May 2010
Location: Sugarcane town Florida
Posts: 13,199
Likes: 0
Received 28 Likes on 22 Posts
Default

Good thing you didn't have to cut your leg off.
TwoSmoke is offline  
Old 05-16-2019, 03:21 PM
  #6  
VegasJen
CFOT Attention Whore
Support Corvetteforum!
Thread Starter
 
VegasJen's Avatar
 
Member Since: Dec 2001
Location: Press "2" for English
Posts: 28,203
Received 59 Likes on 20 Posts
Default

Originally Posted by Der Flieger View Post
Pink nail polish? I thought you were more a 'purple' gurl.
It's actually more of a dark red. The flash just brightened it up.
VegasJen is offline  
Old 05-16-2019, 03:31 PM
  #7  
Silverback51
CF Senior Member
 
Silverback51's Avatar
 
Member Since: Sep 2011
Location: Prescott Arizona
Posts: 6,381
Received 32 Likes on 7 Posts
Default

Originally Posted by KarlK View Post
been cracked for a looong time, great PM program


That does not look like a fresh crack to me.
Silverback51 is online now  
Old 05-16-2019, 03:32 PM
  #8  
KarlK
CF Senior Member
 
KarlK's Avatar
 
Member Since: Sep 2006
Location: No, I'm not related to PeterK
Posts: 45,020
Received 27 Likes on 16 Posts
Default

Originally Posted by Silverback51 View Post


That does not look like a fresh crack to me.
run it till it breaks, fix
KarlK is offline  
Old 05-16-2019, 03:33 PM
  #9  
VegasJen
CFOT Attention Whore
Support Corvetteforum!
Thread Starter
 
VegasJen's Avatar
 
Member Since: Dec 2001
Location: Press "2" for English
Posts: 28,203
Received 59 Likes on 20 Posts
Default

Originally Posted by Silverback51 View Post


That does not look like a fresh crack to me.
I would agree. Quite dirty in there. And while that's true, still impressive to crack that big hunk of steel.
VegasJen is offline  
Old 05-16-2019, 03:44 PM
  #10  
Torqaholic
CF Senior Member
 
Torqaholic's Avatar
 
Member Since: May 2006
Location: Mid-Michigan
Posts: 46,807
Likes: 0
Received 3 Likes on 2 Posts
St. Jude Donor '09
Default

Assuming an 18" radius there would be >1000 square inches. To generate 725psi requires a total force of approximately 750,000 pounds. I'd crack too
Torqaholic is offline  
Old 05-16-2019, 03:51 PM
  #11  
VegasJen
CFOT Attention Whore
Support Corvetteforum!
Thread Starter
 
VegasJen's Avatar
 
Member Since: Dec 2001
Location: Press "2" for English
Posts: 28,203
Received 59 Likes on 20 Posts
Default

Originally Posted by Torqaholic View Post
Assuming an 18" radius there would be >1000 square inches. To generate 725psi requires a total force of approximately 750,000 pounds. I'd crack too
Wow! Then it's got to be insane. Can't remember exactly, but I think the platen is 32" (might be 36", but that seems kind of big).

I'm not doubting you because I don't have the background, but the pump has a maximum operating output of 4500psi. Even though it's rated up to that, we look for it to put out ~4000psi to get the 50bar we're looking for. So how does that work?
VegasJen is offline  
Old 05-16-2019, 03:53 PM
  #12  
TwoSmoke
CF Senior Member
 
TwoSmoke's Avatar
 
Member Since: May 2010
Location: Sugarcane town Florida
Posts: 13,199
Likes: 0
Received 28 Likes on 22 Posts
Default

Originally Posted by Silverback51 View Post


That does not look like a fresh crack to me.
Need pic of a fresh crack to compare it to.
TwoSmoke is offline  
Old 05-16-2019, 03:56 PM
  #13  
larrysb
CF Senior Member
 
larrysb's Avatar
 
Member Since: Aug 2002
Location: $ilicon Vall€y CA
Posts: 8,543
Likes: 0
Received 1 Like on 1 Post
Default

Takes less to crack things than you might expect. The trick is time and cycles of stress on an existing defect. Every cycle of pressure spreads the defect into a bigger and bigger crack, which in turn becomes more susceptible to the pressure.

The defect can be as little as a pit, a bubble in the existing material, a crystal of something foreign in the metal or a speck of corrosion.

Time and repetition will do the trick and crack the mightiest of metals.
larrysb is offline  
Old 05-16-2019, 04:04 PM
  #14  
K-Spaz
CF Senior Member
 
K-Spaz's Avatar
 
Member Since: Jul 2012
Location: Central PA. My AR-15 identifies as a muzzleloader
Posts: 28,607
Received 226 Likes on 185 Posts
I believe in the Beer Fairy
Default

Originally Posted by KarlK View Post
run it till it breaks, fix
In the press world I'm not sure that's so uncommon. Look up the Wyman Gordon press in MA. that was repaired after the platten broke (big welding job) . But it was in use till they deemed it completely unsafe.
K-Spaz is offline  
Old 05-16-2019, 04:07 PM
  #15  
Torqaholic
CF Senior Member
 
Torqaholic's Avatar
 
Member Since: May 2006
Location: Mid-Michigan
Posts: 46,807
Likes: 0
Received 3 Likes on 2 Posts
St. Jude Donor '09
Default

Originally Posted by VegasJen View Post
Wow! Then it's got to be insane. Can't remember exactly, but I think the platen is 32" (might be 36", but that seems kind of big).

I'm not doubting you because I don't have the background, but the pump has a maximum operating output of 4500psi. Even though it's rated up to that, we look for it to put out ~4000psi to get the 50bar we're looking for. So how does that work?

I don't use measurements in bar but wiki says one is only 14.5 psi. So 50 bar is 750 psi. The 4000psi must be stepped down to 750psi by working on an a cylinder that has approximately 5X the output area. It spreads the force.
Torqaholic is offline  
Old 05-16-2019, 04:17 PM
  #16  
K-Spaz
CF Senior Member
 
K-Spaz's Avatar
 
Member Since: Jul 2012
Location: Central PA. My AR-15 identifies as a muzzleloader
Posts: 28,607
Received 226 Likes on 185 Posts
I believe in the Beer Fairy
Default

Originally Posted by Torqaholic View Post
Assuming an 18" radius there would be >1000 square inches. To generate 725psi requires a total force of approximately 750,000 pounds. I'd crack too
A story of area and pressure...

I used to do electronics work for a company in Williamsport , Anchor Darling Valve. A friend of mine was an engineer there, tool and die maker, did design work, jack of all trades. He worked at one point in the inspection dept. He told me they tested ballast valves they'd made for the USS Ronald Reagan and they needed tested to 300%. I don't recall the pressure in PSIG, but the valve itself was a 36" inconel ring that sat on an O-Ring. The Oring had to withstand some millions of pounds of force in that test. I forget all the numbers but I recall him saying they were legitimately scared doing the test, not knowing what would happen if the SHTF.
K-Spaz is offline  
Old 05-16-2019, 04:23 PM
  #17  
Aerovette
CF Senior Member
 
Aerovette's Avatar
 
Member Since: Nov 2001
Location: aka "Splice"
Posts: 29,835
Received 212 Likes on 131 Posts
Default

Originally Posted by TwoSmoke View Post
Need pic of a fresh crack to compare it to.

Aerovette is online now  
Old 05-16-2019, 04:34 PM
  #18  
ptindall
CF Senior Member
 
ptindall's Avatar
 
Member Since: Aug 2006
Location: Picking on the weakest kid in the yard.
Posts: 26,380
Received 36 Likes on 19 Posts
Default

Originally Posted by VegasJen View Post
Wow! Then it's got to be insane. Can't remember exactly, but I think the platen is 32" (might be 36", but that seems kind of big).

I'm not doubting you because I don't have the background, but the pump has a maximum operating output of 4500psi. Even though it's rated up to that, we look for it to put out ~4000psi to get the 50bar we're looking for. So how does that work?
Its not the size of the platen that matters for calculating force. Its the size of the hydraulic piston.


Originally Posted by K-Spaz View Post
A story of area and pressure...

I used to do electronics work for a company in Williamsport , Anchor Darling Valve. A friend of mine was an engineer there, tool and die maker, did design work, jack of all trades. He worked at one point in the inspection dept. He told me they tested ballast valves they'd made for the USS Ronald Reagan and they needed tested to 300%. I don't recall the pressure in PSIG, but the valve itself was a 36" inconel ring that sat on an O-Ring. The Oring had to withstand some millions of pounds of force in that test. I forget all the numbers but I recall him saying they were legitimately scared doing the test, not knowing what would happen if the SHTF.
I used to machine valve bodies for submarines. The final bore was somewhere in the neighborhood of 4" +/-.001. About 24" deep with a number of large grooves along the way. You would rough it out to something like .025 to go, measure, make your offset, and make you final cut. If you missed, you scrapped the whole valve body. If it came out small, there was no way to recut without chatter that would trash the surface finish requirement.

Last edited by ptindall; 05-16-2019 at 04:34 PM.
ptindall is offline  
Old 05-16-2019, 04:39 PM
  #19  
K-Spaz
CF Senior Member
 
K-Spaz's Avatar
 
Member Since: Jul 2012
Location: Central PA. My AR-15 identifies as a muzzleloader
Posts: 28,607
Received 226 Likes on 185 Posts
I believe in the Beer Fairy
Default

Originally Posted by ptindall View Post
I used to machine valve bodies for submarines. The final bore was somewhere in the neighborhood of 4" +/-.001. About 24" deep with a number of large grooves along the way. You would rough it out to something like .025 to go, measure, make your offset, and make you final cut. If you missed, you scrapped the whole valve body. If it came out small, there was no way to recut without chatter that would trash the surface finish requirement.
Similar with these, though I don't know all the details.

I was there 2 of the days they were working on these things. Omg, the noise was unbearable. The hair is standing up on my arms now thinking about it. Omg, chatter. They had big rubber gizmos pressed to the back of the part, which was only about 3/4" thick at the outer edge and I want to say 3" near the center. It has steps on the surface, like at 36" it is 3/4" but at 32" it steps to 1", and so forth. Mother of pearl was that loud. They made em and they passed, but I've never heard tool chatter on a part like that before or since. The cast bodies were no big deal. I worked on the DNC for the vertical mill they ran them on (big mother.) That was the easy part I guess. This big disk was the gate for the gate valve and it was like machining a big inconel potato chip.
K-Spaz is offline  
Old 05-16-2019, 06:04 PM
  #20  
TwoSmoke
CF Senior Member
 
TwoSmoke's Avatar
 
Member Since: May 2010
Location: Sugarcane town Florida
Posts: 13,199
Likes: 0
Received 28 Likes on 22 Posts
Default

Originally Posted by Aerovette View Post
Oh yeah. Much nicer, undamaged crack than the one VJ posted.
TwoSmoke is offline  

Thread Tools
Search this Thread
Quick Reply: Hydraulic press -- how's this for pressure?


Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: