We have been analyzing welding time on a job and found some of our welders were grinding out tacks and others welding over them. Obviously it takes a lot more time grinding them out. My question is, what is common and accepted practice?
I may mention this is 1554.1 GP work on pipe bridges. The...
Excuse my ignorance here - would it be feasible to roll the edge of the profile, weld the circumference to a thick plate and then pressurise the inside to strecth into the dome shape?
I would like to know how the torispherical domes are made for pressure vessels. In particular we are quoting a 3,658m diameter vessel made out of 10mm plate, SA518Gr70. The dome has an upstand of 380mm.
I get more and more need to specify wear plate. Does anyone know where I can find a summary of the different kinds of wear plate available and applications, advantages/disadvantages. My application is mostly quarries, mining etc.
Thx
The plates were pre-machined and assembled in a machined jig which we were hopeful would keep things square enough for our purposes - we only needed the centers to be in-line and squareness were of less importance since we were using spherical roller bearings. Unfortunately a wrong welding...
Hi Mike - it is a tunnel boring machine. You can see some pics of previous machines we have produced here :
http://www.belcher.co.nz/Projects.htm
Hi Ed, thanks for the valuable feedback. Do you know where I can find published data that supports the type of figures you mention?
Does anybody...
Thanks for the feedback so far. The machinist was & still is not happy! Then again the machine in question is of such value and the implications of an unsatisfactory job such that the price of the unhappiness kind of fades.
If you guys look at it and tell me I was wrong I will have to eat...
Thanks Ed. I will try to explain in more detail. If you imagine facing the end flange of a pipe-like structure. The bearings are supported in the "pipe" which has an approx id=31,5". The bearings are spaced 27.56" apart to support the the center shaft of 2" dia. Where the central shaft sticks...
I am in an argument with a mobile machining company at the moment. We stopped the job because we felt the equipment they were using was not sturdy enough and severe chatter was visible during the inithial cut. They claim the equipment was suitable and the final cut would have provided a...
Obviously it touched a nerve with you Gkranz. Fact is, component suppliers offer to do the design - it is part and parcel of their offer: They claim to employ design engineers, they offer to quote on what you need, they provide you with a hydraulic circuit schematic listing the required...
Some of my guys rarely finish a piping job with no leaks. Watching them they seem to over-fasten if anything. I read that fastening torque is important and came accross some sketchy info on a method of measuring the number of flats and also some tables specifying fastening torque.
What is the...
If I were to stir a tin of cold syrup with a spoon, then over time the syrup will flow easier - heat is generated in a constant pressure environment. This heat is due to the interaction of the syrup molecules being pushed around by my labour. My labour also goes into kinetic energy, but when the...
Thanks guys, this basically confirmed what I already knew. I think a ball type switch would be less sensitive to false alarms due to rocking motion because you would not have the wave amplification effect as with the mercury type.
VE1BLL, I did look at that option, but this is a simple...
I am looking for a suitable tilt switch for a mobile scissor platform. In the past I have tried mercury switches but in the mobile application that tended to cause false alarms, presumeably due to the dynamic motion of the base vehicle and its effect on the mercury.
The platform advances slowly...
I was trained to the ISO drawing standard, but through experience learnt that:
It is OK to specify H7/g6 - you only have to reject a part once and then everybody knows. Sounds harsh - but heck, my time costs more than the guy on the floor and hence I only need to communicate my design intention...
Just remember that if your vehicle is also going on the main roads at high speed you will want to minimize the sprung mass of the wheel assembly itself to ensure acceptable dynamics over uneven surfaces at speed. Hence a hydraulic wheel motor may not be suitable unless you use a CV joint type...
I tried it and it works well, but is limited in the components that are available. To get components added you have to contact the University and I can just imagine how long it will take our theoretical cousins to add just one component - so as a practical tool unfortunately I think of limited use.
