seam less pipes are having with out weld but produced by extension process it is costly than seam
The adjective SEAMLESS has 3 senses:1. not having or joined by a seam or seams2. used especially of skin3. perfectly consistent and coherent
Two pieces of aluminum can be joined byAdhering (e.g. with contact cement)BandingBinding (e.g with weatherstripping or edging)Bolting or screwingHingingJoining (e.g. using a folded lap joint, dovetails, or mortise and tenon)Riveting (e.g. with pop rivets made with aluminum or stainless steel)TapingWelding (e.g. using spot welds, a seam weld, or a fillet weld)
Wear goggles at all times while the machine is turned on. I cannot stress this enough. Ive had more metal splinters in my eyes than I care to remember and can tell you that they arent pleasant! It doesnt matter what material you are working on, WEAR GOGGLES! Ensure all safety guards are engaged and locked securely. Before you turn the machine on, switch off the mains power supply and lock it. Open the casing to access the belt / s (if applicable to your particular machine) and check both rollers for damage and debris. Then check the belt / s. Make sure there arent any tears in them and that the seam is intact. Also make sure there are no other damaged parts that may rub or cut into the belt. When you are satisfied that the machine is safe to use, close it and lock it. Turn the mains back on when you are ready to use it. Important note on locking the mains switch: Ive had my hand spun round in the belt of a linisher before by some idiot who thought the mains was turned off for no reason! If you cant lock the mains switch in the off position, tape a note to it to warn others not to turn it on and why. Gloves are also a very good idea, especially when working with small workpieces. Getting your fingers ground to the bone is not fun. A good leather glove wont care if it gets sanded... your skin will! There is also the heat factor, especially where metal objects are concerned. A lot of friction is caused between a workpiece and a linisher belt / wheel and that can make the workpiece very hot very quickly. Wood and most plastics are an exception to this rule, as they are poor conductors of heat. Lastly: Treat the machine with respect. As with any power tool, it has the ability to hurt you badly if you treat it wrong. Dont put too much pressure on the belt / wheel. Dont put the workpiece at an angle that is likely to let it get jammed between the plate and belt / wheel. Try to keep the workpiece flat to the plate when possible. Always try to avoid using the extreme edges of the belt / wheel as the workpiece is more likely to find any small tears and could get jammed on them. Believe me, lax regard for your safety when using machines like these is the best way to sustain a potentially debilitating injury. I have been lucky in that I still have my hand and I still have my sight. It could have been a lot worse!
Common sense.
ERW (Electric Resistance Welding) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; hence ERW pipe has a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
Non-seemless pipe is rolled from a flat piece of metal and welded lengthways to form the piping. Seemless pipe is extruded and has no seems and is generally stronger.
Seamless (SMLS) pipe is formed by drawing a solid billet over a piercing rod to create the hollow shell. Seamless pipe withstands pressure better than other types, and is often more easily available than welded pipe.Welded pipe is formed by rolling plate and welding the seam. The weld flash can be removed from the outside or inside surfaces using a scarfing blade. The weld zone can also be heat treated to make the seam less visible.
One pipe is electric resistance welded (erw) the other is extruded through a thimble. In other words one has a seam the other doesn't.
The difference between seamless and welded (as it is commonly known) pipes is the welded joint along the longitudinal direction. Seamless pipes are manufactured by continuous extrusion process. Seamless pipes have greater bursting and tensile strength than the welded ones.
A conspicuous seam is a visible seam that is intentionally highlighted as a design feature, whereas an inconspicuous seam is a seam that is hidden or blended into the fabric to create a seamless look. Conspicuous seams are typically used for decorative purposes, while inconspicuous seams are used for a more polished and refined finish.
The pipe which is formed by seam welding.
A cap sleeve offer some visual interest at the seam created by a slight poof. A set in sleeve is meant to project a seamless integration.
A hem creates a seam. A seam is the intersection between two pieces of cloth or two parts of the same piece of cloth.
'Seamless' means without a 'seam' (a seam is a join therefore seamless stockings are kitted as a tube rather than being cut out of flat material then joined into a tube by stitching). 'Stainless' means without a 'stain' ( a stain is a discoloration or blemish, thus stainless steel will not rust and and therefore a knife made out of this steel will remain new looking throughout its life while an ordinary knife blade will blacken and rust with age).
Seamed pipe is a weak cheap pipe.low pressure.it is cold rolled steel and when rolled it is welded.the seam.
Most pipes are made by taking a strip of metal, rolling it up and then fusing the seam together. They're almost always weaker along the seam than anywhere else. There are ways of making pipes where the wall is a single piece that hasn't been welded shut. They're stronger , more expensive and they're called seamless.