1, how to distinguish elbow elbow?
The difference between elbow and elbow as in essence is the "head" and "tube" of the other, but in the production process is very different. The most basic difference is relatively relatively short pipe elbow.R=1 times to 2 times the elbow, the big multiples called elbow straight. You can use off the shelf pipe bending machine bending in the production process of cold bending, one-time completion without the two anti-corrosion. But to elbow manufacturers custom-made, to do anti-corrosion, order cycle length. Elbow bend to price than high but the price is much higher than the elbow, no preservative treatment of bending pipe is easy to damage is of well-known but, because of cheap price in some of the requirements are not very high engineering use very much.
2, elbow materials of cast iron, stainless steel, alloy steel, carbon steel, forging cast iron, non-ferrous metals and plastics. Direct welding and pipe connection mode (the most common way) flange connection, threaded connection and socket type connection.
3, elbow symbol: schxx is the wall thickness, 90E (s) said the short radius elbow with 90 DEG 90E; (L) said the long radius elbow with 90 DEG 45e; (L) said the long radius elbow with 45 DEG 45e; (s) said the short radius elbow with 45 DEG 180E; (s) said the short radius 180 bend; 180E (L) said the long radius elbow with 180 DEG R; (c) said concentric reducers; R (E) said eccentric reducers; t (s) said EQUIDIAMETER three; t (R) said heterediameter three; Cr (s) said EQUIDIAMETER four; Cr (R) said heterediameter four; C cap; classification of elbow, according to minutes of its radius of curvature, and can be divided into long radius elbow short radius elbow.
A long radius elbow bend refers to its radius of curvature equal to 1.5 times the outer diameter of the pipe, or R=1.5D. A short radius elbow means that its radius of curvature is equal to the outer diameter of the pipe, or R=D. The D in the formula is the elbow diameter, and R is the radius of curvature. If divided by the pressure level to about seventeen, and the American Standard pipe is the same, are: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140, Sch160, XXS, and STD is one of the most commonly used XS two.
According to the elbow angle, there are 45o elbow, 90o elbow and 180o elbow. As a result of many kinds of elbows, orders are taken when the regular order representation: such as "LRSTD90o8", said the long radius, pressure rating to STD, 90o 8 "; elbow; again," SRXS45o4 "said short radius, pressure rating to XS, 45o 4" elbow.
Two, elbow bend maintenance method
1, long-term storage elbow bend, should be checked regularly, often exposed processing surface must be clean, remove dirt, neatly stored in the indoor ventilation dry place, prohibit piling or outdoor storage. Always keep the elbows dry and ventilated, keep the equipment clean and tidy and store it in the correct storage method.
2. When installing, the elbow bent pipe can be directly connected to the pipeline by the connecting way, and the utility model can be installed according to the position used. Under normal circumstances, can be installed in any position on the pipeline, but need to facilitate the operation of the test, pay attention to the cut-off elbow, medium flow should be vertical valve, down to the upper reaches, elbow bend can only be installed horizontally. Elbow installation should pay attention to sealing, to prevent leakage phenomenon, affecting the normal operation of the pipe.
3, elbow bend ball valve, globe valve, gate valve use, only for full open or full closed, do not promise to do adjustment flow, so as not to close the cover erosion, accelerated wear and tear. The valve and the upper thread stop valve are provided with an inverted sealing device, and the hand wheel is screwed to the top position to be screwed, so that the medium can be prevented from leaking from the filling.