Advice on welding 10t lifting eye

[BigDan83]

Has anyone on here had the pleasure of welding one of these before?

I've been given this to do, with very little information. We 99% of the time just weld pipe, but this has somehow this made it onto my bench. I've only been told it needs a 25mm fillet weld.

So my questions to anyone who has done something like this are:

Do these normally have some sort of NDT? (I've only been told that they will be load tested)

What size prep on this would it need? The bottom plate is 30mm, and the lifting eye is 50mm.

Would you use low hi's?

Would something like this need a preheat?

Or should I say I'm not doing it, with very little info?

Cheers Dan

 

[Brad93]

They will be load tested 25% over the SWL. Iirc. @Jim Davey can confirm and probably shed more light.
I would definitely use a low hydrogen consumable such as a 7018 or 7016, purely for the better mechanical properties.

It may need preheat. I would give it 75 degrees as a minimum. I'm guessing you don't know the alloy?

 

[pedrobedro]

I'd have that drilled through the bottom plate and some big countersunk bolts through it or modified so the top goes all the way through the bottom plate to weld both sides.

 

[nickk]

Not much room for a decent size fillet,& still leave space for the bolt head.

 

[pedrobedro]

The six massive bolt holes are completely redundant if the weld fails, they are there for decoration as far as I can see.

 

[gaz_moose]

aldi buzz box should have that stuck together in no time.

 

[BigDan83]

I'm guessing you don't know the alloy?

All I've been told it's mild steel.

Not much room for a decent size fillet,& still leave space for the bolt head.

I thought that myself.

 

[BigDan83]

aldi buzz box should have that stuck together in no time.

Standard that is haha

 

[Wildefalcon]

That would benefit from a redesign. The eye plate should be pushed through a slot in the bolt plate. Ideally so that it wedges without welding, then welded underneath.

The current arrangement is not ideal.

 

[Brad93]

That would benefit from a redesign. The eye plate should be pushed through a slot in the bolt plate. Ideally so that it wedges without welding, then welded underneath.

The current arrangement is not ideal.

I've never once seen a pad eye welded in that manner. You put the weld under shear force which is a lot lower than its transverse or longitudal strength.

 

[Richard.]

You don’t have a Subarc at your expense do ya?

The guys are right, you will not achieve a suitable size fillet on that and leave enough clearance for bolt heads. If washers are going in under it too you got no chance. First off I’d look at making the plates bigger to allow you to get a 25mm leg.
I’m not telling you your wps for it but it definitely wants a preheat. Around 100° And hold it at that to soak through.
You also want to keep your interpass down to 150 maximum really to retain the mechanicals best you can.
7016’s or 7018’s in 4mm at 160 amps would be where I’d be looking personally. Stagger your stop starts and grind between layers.
Unless you have access to some UT equipment or X-ray. I would say set up a dummy, weld it up and take some macros.
Then send off some for charpys. I’m going to assume (I hope) you will be given a qualified wpqr for this.

 

[Brad93]

If you haven't got a WPS don't do it. If the thing breaks and kills someone, it will come back and your firm could try to plant it on you.

 

[Richard.]

That would benefit from a redesign. The eye plate should be pushed through a slot in the bolt plate. Ideally so that it wedges without welding, then welded underneath.

The current arrangement is not ideal.

This whole idea of setting the eye into the plate and welding from the back is a disaster.
The whole point is to have reinforced weld metal around the eye to give it strength. A fillet weld is exactly the way to do this for absolute optimum strength.
It’s a proved, tried and tested design and not one we want to be changing over a diy forum. I’ve seen these eyes made exactly as the op is showing lifting 100’s of tonnes such as windtower sections, huge beams for bridges, under ground tanks etc and it’s always a multi pass fillet weld. Although these are designed for a straight up lift you have to assume some side ways forces are going to be applied and there for the reinforcement from a fillet weld design is essential.

 

[Richard.]

If you haven't got a WPS don't do it. If the thing breaks and kills someone, it will come back and your firm could try to plant it on you.

I’m quoting this post because it’s the best one on here so far.
You do not want to make yourself accountable for that based on “it’s a 25mm leg”. This should definitely be welded to a qualified wps. You should also make sure your codes cover the job too which I’m sure they will as you weld pipe but check it. You should also by law have these inspected by Lola. Making lifting eyes like this is not a cheap thing and if those costs cannot be passed onto the client then it’s just not viable.
If the client is going to have them tested get that in writing.

 

[Kent]

I’m quoting this post because it’s the best one on here so far.
You do not want to make yourself accountable for that based on “it’s a 25mm leg”. This should definitely be welded to a qualified wps. You should also make sure your codes cover the job too which I’m sure they will as you weld pipe but check it. You should also by law have these inspected by Lola. Making lifting eyes like this is not a cheap thing and if those costs cannot be passed onto the client then it’s just not viable.
If the client is going to have them tested get that in writing.

Now I have done a fair few on site, normally not as big. However I have never been handed a wp. Usually the eye goes onto an existing large part for craning. Have I been taking too big a chance because it's normally an hour before or less that it's needed

 

[Brad93]

Now I have done a fair few on site, normally not as big. However I have never been handed a wp. Usually the eye goes onto an existing large part for craning. Have I been taking too big a chance because it's normally an hour before or less that it's needed

I've welded a few small ones on site. Two hundred kilos max. Never had a problem. But 200kg is a long way of 10t.

 

[Richard.]

Have I been taking too big a chance because it's normally an hour before or less that it's needed

Only you can decide that mate.
Personally if I was welding a lifting eye on something I would want a qualified wps. I couldn’t live with myself if for any reason it failed and killed someone. Chances are unlikely because we have a general idea of what we need to do. You are not allowed to weld an eye on something to take load that has not been tested under Lola regs. That will finish you off behind bars if it goes badly wrong.

 

[Parm]

aldi buzz box should have that stuck together in no time.

What's wrong with Gorilla Tape, fixes everything on the telly

 

[rory1]

There's a BS for standard pad eyes, il see if I can dig it out for you

Edit: found something - This isn't the BS but it's something similar for container lifting pad eyes . Don't take it as gospel but it gives a bit of an idea

https://www.stemar.com/tools-en/publications/offshore-pad-eyes-en

 

[Gareth J]

I'm no expert and could very well be wrong but is a 50mm plate for the eye a bit overkill for just 10tons?

If there is scope to loose some of the width, you will have more room for weld.