Closure Plate for HSS Column, Seal Welded? Strength?
Closure Plate for HSS Column, Seal Welded? Strength?
(OP)
Hey all,
I am putting a closure plate at the top of a HSS column. I would like to make it water tight - thus seal welded. I am reading mixed opinions on seal weld strength here. The structure has roof deck and the closure plate need to be able to hold down the roof deck - the max un-factored load is approx. 2 k. Will a seal weld do? Here is how I have it right now. Should I specify the size of the seal weld? Really any size will do for this. What symbol should I use?
Also, I am curious - for a practical standpoint, how does the shop person get the closure plate inside the HSS column perfect and weld?
I am putting a closure plate at the top of a HSS column. I would like to make it water tight - thus seal welded. I am reading mixed opinions on seal weld strength here. The structure has roof deck and the closure plate need to be able to hold down the roof deck - the max un-factored load is approx. 2 k. Will a seal weld do? Here is how I have it right now. Should I specify the size of the seal weld? Really any size will do for this. What symbol should I use?
Also, I am curious - for a practical standpoint, how does the shop person get the closure plate inside the HSS column perfect and weld?





RE: Closure Plate for HSS Column, Seal Welded? Strength?
To illustrate, my welder walks back in at 11:45 and tells me he had "seal welded" the plate. Do I tell him to go add more metal, or do I tell him to go do the other column plate in the afternoon? How much weld is a "seal weld" ?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Closure Plate for HSS Column, Seal Welded? Strength?
If you do not a perfectly flat top, then do NOT require the top be ground flat. That will save a lot of time on each vertical tube steel joint.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Best regards - Al
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Question, will the bevel weld give a good seal? My primary concern is to avoid getting moisture in the column. Can I specify the bevel weld a seal weld?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Well, a weld will give a good seal. A bevel weld will give you an easier weld. Just to prevent water vapor entry a 1/8 or 3/16 or 1/4 weld is more than adequate.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Bevel the tube. This will give you the full thickness of the closure plate to prevent burning off the edges of the plate and having a crappy looking edge.
Yes...the bevel weld will provide a good "seal".
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Well, what is drawn places the cover plate "inside" the end of the rounded-corner tube steel, right?
So, it will be easier to bevel the pate than the inside wall of the tube steel.
True - IF you were placing the cover plate over the end of the vertical tube, then I'd agree with you about beveling the tube steel walls. But as-drawn? By the way, the originalposter is going to have trouble getting the corners of the coverplate cut exactly and rounded off anyway - fitting a plate inside the end of the tube is very difficult.
Better/cheaper/faster. MOVE the cover plate so it is placed on top of the HSS piece. (The cover plate will need to be 1/2 bigger all around since the HSS walls are 1/4 thick. Then, after tacking the cover plate, the welder/fitter can grind off the corners of the cover plate to smooth the edges.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
If all you want is a seal but little structural strength, you set the cap into the HSS, leave a root gap all the way around (using TIG wire to provide the space), use a magnetic fixture to hold the part until it's tacked, then simply buzz a MIG pass around the joint to provide the seal, grinding flush if necessary to make it pretty.
If you want structural strength, the simplest option is to set the plate in and deposit a FILLET around the ID. The plate will not be flush, but that may not matter.
If the plate needs to be flush and structural strength is required, then you're stuck with bevelling. Bevelling the ID of the HSS is very difficult- don't do it. Bevel either the OD and set the plate on, or bevel the plate. Which is more likely to be labour efficient and to give a good quality weld depends on what orientation the piece will be in during welding.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
RE: Closure Plate for HSS Column, Seal Welded? Strength?
The 1/8" gap PJP is fine as long as all you want is a seal, and if you can't tolerate the cap being below flush, i.e. on the top of a vertical column with exposed top where you don't want water to pond.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Dik
RE: Closure Plate for HSS Column, Seal Welded? Strength?
I didn't want a larger plate because I wanted flush edges and didn't want to cope the beam just to accommodate the plate. I would be curious though, from a labor standpoint, whether a fabricator would prefer to 1) fillet weld a larger plate and cope the beam top flange or 2) PJP a HSS-OD-shaped plate and install the beam as usual.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Ah ha on the "set the plate in". Thanks. The reason I wanted it to be flush is because I have roof deck to be attached to the top of column.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Dik
RE: Closure Plate for HSS Column, Seal Welded? Strength?
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Closure Plate for HSS Column, Seal Welded? Strength?
But that has to be a field weld. Here, he is doing a shop joint (I hope!) on the bolting plate; followed by a field bolted joint of flat plate to horizontal beam.
RE: Closure Plate for HSS Column, Seal Welded? Strength?
RE: Closure Plate for HSS Column, Seal Welded? Strength?