Control valve repair.

[Pete.]

One of the hydraulic packs at work packed up this week. New parts are a week away so I said I'd repair this one in the meantime.

This is a flow and pressure control valve. It gets constantly adjusted and this has caused the thread to wear in one spot.

So if you wind the control right out it slips on the thread and you can't get any pressure on the machine. I found a bit of 303 stainless and re-made that part.

First turn the three diameters on my lathe.

Then thread the middle section 8mm x 1.0 pitch. I roughed it out with the tool shown here and finished it with a die afterwards. Never thought I'd ever use that die since I got it but now I have

After that I turned the groove for the o-ring and parted it off but no photo of that because it was badly blurred. Then I drilled the hole for the control knob screw.

New part next to the old one.

Ready for re-assembly. All in all took me about 2.5 hrs.

If you think it's a bit odd to be machining around midnight then you'd be right - except I am working 3-11pm right now so I don't normally get home till around midnight. Tonight we got done early so really I've been working on company time. Only seem fair since it is a bit for their machine

 

[Windy Miller]

Nice job Pete!

 

[slimjim]

Nice little job.

 

[awemawson]

Nicely done Pete, your firm are lucky to have your skills on hand.

 

[123hotchef]

top work

 

[mtt.tr]

Nice bit of work

 

[Pete.]

Thanks

I put it here to show that what looks like a daunting part (a 2500psi control valve for a 20 grand hydraulic pack) is nothing more than 4 diameters, a groove, a thread and a small hole. The only bit that got any special attention was the seal groove, I reproduced that to within 1 thou width and depth and polished the OD of the guiding flanges with 800 grit emery after putting a tiny bevel on them so they don't score up the bore of the valve housing. The rest was comparative measurements with digital calipers (I measured the original, set to caliper to zero then turned the new one down to 'zero'. for each diameter. Mk1 eyeball for the hole as it only secures the plastic knob.

 

[mtt.tr]

Thanks

I put it here to show that what looks like a daunting part (a 2500psi control valve for a 20 grand hydraulic pack) is nothing more than 4 diameters, a groove, a thread and a small hole. The only bit that got any special attention was the seal groove, I reproduced that to within 1 thou width and depth and polished the OD of the guiding flanges with 800 grit emery after putting a tiny bevel on them so they don't score up the bore of the valve housing. The rest was comparative measurements with digital calipers (I measured the original, set to caliper to zero then turned the new one down to 'zero'. for each diameter. Mk1 eyeball for the hole as it only secures the plastic knob.

That my view on almost all challenges, break it down bit by bit and its doable.

 

[Parm]

Thanks

I put it here to show that what looks like a daunting part (a 2500psi control valve for a 20 grand hydraulic pack) is nothing more than 4 diameters, a groove, a thread and a small hole. The only bit that got any special attention was the seal groove, I reproduced that to within 1 thou width and depth and polished the OD of the guiding flanges with 800 grit emery after putting a tiny bevel on them so they don't score up the bore of the valve housing. The rest was comparative measurements with digital calipers (I measured the original, set to caliper to zero then turned the new one down to 'zero'. for each diameter. Mk1 eyeball for the hole as it only secures the plastic knob.

That my view on almost all challenges, break it down bit by bit and its doable.

The skill is having the ability to break things down and reverse engineer when doing stuff like this. Neat little job and your firm are incredibly lucky to have you. Over night repair and job stays on track

 

[mm289]

Awesome work Pete, now all you need to do is convince the firm to invest in kitting out your machine shop with even more tasty gear so you can keep all their kit running

Cheers,
Paul.

 

[mtt.tr]

The skill is having the ability to break things down and reverse engineer when doing stuff like this. Neat little job and your firm are incredibly lucky to have you. Over night repair and job stays on track

I agree, and take it for granted.

 

[Bladevane]

Nice work. The new part looks just like a proper one!