Water Tanks and Splicing Plates

Your description has me confused, but if you wish to splice in pieces to one side of your angle members, then you need 394 x 6 mm plate. If you are simply going over the top of the existing structure, I would use the same. I would look into using A242 material for its weathering characteristics in an over the top application, but try to match the parent material closely for cut and splice.

DEAR JERRY,

I MAY NEED TO CLARIFY THE MATTER A BIT MORE PRECISELY HERE. THE ANGLE SIZE 100X100X6 MM, THAT I MENTIONED IS OF A-105 MATERIAL. THE TOTAL LENGTH OF ANGLE CONNECTED TO THE RAFTER COMES TO APPROX 15M. THE STANDARD SIZE OF SInGLE LENGTH ANGLE IS 6M. WE NEED TO EXTEND THE ANGLE IN THIS CASE to get thr required length.

SO, MY QUESTION IS: WHAT WOULD BE THE SIZE OF SPLICE PLATE WE WILL BE PROVIDING IN ORDER TO CONNECT THE 2, (i.e, if we are following a code or standard) thereby making it 1 single connection to the rafter.

ANYWAYS, APPRECIATE UR QUICK RESPONSE TO MY QUERY. THANKS.

Are you welding or riveting?

iT WILL BE WELDING

The connecting components MUST have same sections as base profile and the welding should be able to transmit same load as base profile. What you want to achieve is CONTINUITY of portance. Sections have to be at least equal for traction/compression loads and J have to be at least equal to transmit bending and offer correct stability.

For the material you're using, double V groove preps for full penetration using 7018 or E70S6 for filler alloy should do the trick for you without the use of splicing plates.

Should you choose to use the plates anyway, I would mke sure that they extend 150mm to either side of the joint, with the last 75mm on each end tapered so as to reduce the stress risers.

Sorry, I have tried to draw a picture of this but can't seem to get it to upload.

I got the idea. doesn't matter about the picture. Just a small doubt about the taper size. Instead of going for taper, I think having the edges rounded off ( no sharp edges ) should be just fine.

What do u say?

The idea is to avoid a sudden change of thickness across the 100mm dimension; ie, have the splicing plate cut so that the short side (100mm width) angles out along the long 300 - 400mm length to a "point" formed by a 25mm radius on each end.

YEAH, THIS SOLUTION LOOKS PLAUSIBLE TO ME AND I THINK I COULD MAKE THIS AS A PROCEDURE TO THE CLIENT.

THANKS FOR THE IDEA.

Hello All,

You do not state where you are located and if the tank is used for storing potable water. A lot more information would go a long way in answering your question by Forum members. Also, what's the age of the tank and the environmental (weather) factors acting upon it?

The next question I have to ask is: since the original steel is so badly corroded why aren't you replacing the existing tank roof structural members instead of contemplating a "half-*ss" repair job and throw good money after bad?????...as the new splicing steel is very apt to become just as corroded when given enough time and factors which are currently promoting the corrosion in the first place. Better off spending some money determining what's causing the corrosion of the steel members, then rectifying it, followed by installation of a new roof. Additionally, due to the corroded nature of the existing steel, there may not be enough good material, or "meat" left to make a proper splice where the roof structural members are strong enough to adequately and safely carry the superimposed service loads.

Second question I have is: who recommended this repair procedure? Was that person a qualified structural engineer who is licensed to perform engineering in your neck of the woods???

Third question I have: what is the condition of the center drum wall and the tank exterior wall, and what are the composed of? Has anyone who is qualified to do so evaluated those walls? If they're as equally corroded, may it's high time to replace the entire water tank.

This looks and smells like a huge live safety issue and liability problem to me if you're foregoing the services of a Licensed Professional Engineer.

Enough said...

Hello all,

I got the solution from Jerry New Hampshire. Basically, since this is just a maintenance contract, and taking cost into consideration, the client recommended that we go ahead with repairs like replacing angle supports.

Thats all there is to it. Thats why didn't delve into so many other citical information details.