Require Bracing for Actuator Valve 6500lbs Vertical? 3

[elaineabc]

Dear friends,

I have a 20" Actuator Valve with 6500 lbs weight and 14 feet above ground, vertical setting. The valve will thrust 156,000 lbs force (80 Tons) with double acting cylinder with 1 hydraulic cylinder sits on top. The vendor told us we do not require to use external anchor or bracing but being the height of 14 feet above ground, we feel uneasy about its structure. Please advise with your experience and expert judgment. Thank you.

 

[BigInch]

You can place a 20" with actuator above ground, if the structure is adequate. The actuator cylinder load should not be transmitted to the structure. Cylinder loads are converted into torque and rotate the valve. No forces should really leave the valve itself. I'd be more worried about shearing the valve shaft, but then again, I haven't seen the structure either.

 

[mizzoueng]

I seem to be missing a few things..

What kind of valve are we talking about here?

You said 14' above ground, is that bottom of valve, top of valve, or center of valve?

Is it connected to piping on both sides? or a tank? etc.

What is the valve currently sitting on, ie what is holding the weight?

 

[JimCasey]

Height of the valve above the ground is not really significant.

The valve is supported by the piping in which it is installed. The piping must be supported appropriately so it is not sagging with the load of the valve, with its own weight, and with the weight of whatever is flowing through it. Also the pipe hangers should be able to snub out vibrations due to turbulence. Pipe hanger requirements have a lot of dependence on the length of the pipe, configuration, flowrate, mass of the stuff flowing through it, Thermal expansion effects, etc.

It is good that the actuator is on top of the valve. Otherwise an actuator that heavy would cause bending loads on the bonnet/stem/bearings/packing and it would be a maintenance headache. A non-vertically mounted actuator should be supported to prevent bending loads on the yoke, and the support should be thoughtfully designed so that it does not introduce its own bending loads on the valve if the pipe moves. Even with the actuator vertical, evaluate the installation to see if you need to brace it for vibration or seismic loads.

 

[mizzoueng]

You cannot depend on the piping to hold the weight of the valve. It works in smaller situations, but if you are using something like DIP or CI then you will need some type of bracing under the valve itself to take the weight off the piping.

 

[elaineabc]

The actuator was installed yesterday. The valve is located at the bottom of the actuator (14'). Part of the valve is underground.
Big Inch: You are absolutely right,
"You can place a 20" with actuator above ground, if the structure is adequate. The actuator cylinder load should not be transmitted to the structure. Cylinder loads are converted into torque and rotate the valve. No forces should really leave the valve itself. I'd be more worried about shearing the valve shaft, but then again, I haven't seen the structure either."
My only worry is we encounter high wind close to 100 mph, we will tip this structure. But how often do we have 100 mph wind, and if we do, other structure will not stand either. So I will leave this without bracing because the anchor plate is adequate to support this tall structure. Thanks.

 

[BigInch]

Thank you for your kind confirmation. In most cases a 20" pipe can even lift up an entire attached scrubbing vessel. There's a lot of inherent strength in large diameter pipe. I've seen a 12" pipe lift up a 10 foot tall vessel a good 8 to 10 inches off the floor. We had to temporarily unbolt the vessle from its foundation and let it float on the pipe itself.

As I said, without seeing the structures, I can't be sure how strong I can even think they might be and your wind load statement does not add to my warm feeling of security, but then again, it would not surprise me if the pipes remain in place after a 150 mph wind. You may go out there and find the structures gone and the pipes and valves still perfectly in place. (Inshallah) I have found that wind loads do not do as much misplacement and damage as large temperature changes. Temperature changes on free pipe can squash things up very quickly.

http://virtualpipeline.spaces.msn.com