Lifting Pressure Vessel from horizontal position to vertical position ( on its feet) using one crane

[strainstress]

Hi,

One of our cranes has stopped working. So we have only functional crane in the shop.

Any ideas on how lift-up the the pressure vessel from its current position (lying horiztonal on ground) to vertical position (on its feet).

Lifting lugs are located on the top head. Pressure Vessel is 90" ID by 200" tall weighing roughly 5000 lbs empty.

Thanks

 

[strainstress]

We do have forklifts in the shop

 

[dhengr]

Strainstress:
The vessel is 7.5' dia. and about 17' tall, and weighs 5kips. But, we don’t know anything about the head shape, the location and orientation of the lifting lugs, or the design of the legs or feet. Maybe a sketch would be in order. Can you roll the vessel at all to orient the lifting lugs. Obviously, it is best if you lift in the plane of a couple lifting lugs, not perpendicular to their plane (out of plane bending and prying). In any case, you have to take a look at their stresses during this lift, and what they might do to the head and the lugs. That load will be about 2.5k depending upon the tank C.G. location. The same load will be applied to one or two feet, and the question is, can the feet or legs take this lateral load (cantilever loading and end moment at the tank) during the early stages of the lift. I’m not sure how you would lift this differently even if you had two cranes, except that you might be able to lift the feet off the floor during the early stages of the lift, if they are particularly fragile. There are a number of different sling arrangements that you might use, and you probably don’t have some of them. Maybe you could bolt a beam btwn. two lugs and lift from the center of the beam if that helped. You might brace btwn. the legs to stiffen them. Get you Engineering Mechanics (Statics) and Strength of Materials books out and thing through the lift at 20̊ increments. Ask the shop guys, crane operator, how they would do this, and then check the loads and stresses imposed.

 

[chicopee]

Obviously, a two crane pick is the method however, with one crane down, lifting that vessel requires a more demanding approach. First, I would determine the C.G. of that vessel so that the crane hook can be directly in line. A long enough one leg sling would be then attached to the lifting lug at the top head. A second one leg sling, chain type, designed to be used with an electric hoist would be between the crane hook and the tank bottom. This chain must long enough so that when the vessel is suspended it can be increased in length to let the vessel tilt upward. Obviously, the electric power cord, the pendant harness and the chain must be long enough to allow the vessel tilt without running of these materials. The problems: 1)during the initial hook up some type of material should protect the tank head from abrasion or denting by the one leg sling 2) the loads on the one leg slings will much higher than the tank weight, so both one leg sling must be properly rated 3) the chain sling must be secured to the bottom of the tank and hopefully there is a lifting lug that would be used with a two crane pick. If there is no bottom lifting lug, I would not secure the chain to one of the tank legs, instead, I would explore the use of a synthetic web sling long enough to be wrapped around the tank twice and then have the eyes of that synthetic web sling hooked to the chain hook. It is imperative that the wrap around the tank does not slide during lift and tilt; may be a manhole or handholes will prevent sliding. As the tank is lifted you would slacken the chain allowing the tank to tilt. When the tank is nearly upright then you would start disengaging the chain from the tank since it would be suspended by the top sling.

 

[Duwe6]

Or 'tail' the vessel with the forklift. Forks under the vessel; or prefferably lifting a choker attached to the tailing lug.

 

[chicopee]

Yeah , tailing the vessel with a forktruck could work as long a the forks can go high enough without the tank legs dragging on the ground and both ends are lifted simultaneously.

 

[strainstress]

Thanks everyone for the suggestions.

We were successful in lifting the pressure vessel by tailing vessel with the forktruck, using straps long (choked to 2 legs and lifted at one point) enough to prevent interference when vessel is lifted into vertical position by the crane.

Everything went smoothly. Thanks again

 

[dineshakabari]

You may need to use chain pulley block at tailing lug. Once the vessel in air slowly losing the chain of chain pulley block. Certain safety precautions need to take while loosening the chain pulley block. I guess experienced fellow of construction team will get idea of this.