Seamless steel pipe is widely used in our daily life, it can be used as line pipe for oil, natural gas, water and fluid transmission purpose, API 5CT Casing, API 5CT Tubing, drill pipe, boiler tube, mechanical pipe, cylinder pipe, etc. Here we will introduce the standard and usage of cabon seamless steel pipe:
API 5L Gr.B: Specifiaction for line pipe.
ASTM A 106 Gr. B: Seamless carbon steel pipes?for high-temperature service.
ASTM A 53: Specification for black steel seamless pipes.
ASTM A 161: Seamless low-carbon and carbon molybdenum steel still tubes for refinery service.
ASTM A179: Specification for seamless cold-drawn low-carbon steel heat-exchanger and condenser tubes.
ASTM A192: Specification for seamless carbon steel boiler tubes for high-pressure service.
ASTM A 210: Specification for seamless medium-carbon steel boiler and superheater pipes.
ASTM A213: Specification for seamless ferrite alloy steel boiler, superheater and heat-exchanger pipes.
ASTM A 519: Seamless carbon and alloy steel for mechanical tubing.
ASTM A 556: Seamless cold-drawn carbon steel feedwater heater tubes.
Xinyue Steel can provide production range of seamless carbon steel pipe from 10.3mm to 914.1mm.
Seamless elbow is manufactured by the seamless steel pipe, through hot push, press or extrusion processes, no seam on the elbow body.
Welded elbow is manufactured by welded steel pipe, same processes with seamless elbow.But there is a seam on the elbow body.
Prime steel pipe tells you the differences between seamless elbow and welded elbow on raw material, manufacturing processes, performances, appearances, sizes, applications, cost prices etc.
1. Appearance difference
The biggest difference between seamless elbows and welded elbows are whether there is a weld, but now many of the welded steel pipes will be polished off the welding seam before they leave the factory. The elbow that is made out of this steel pipe is invisible to the welding seam.There are a lot of exporter sell this kind of fake seamless elbow to customers. This kind of elbow is difficult to distinguish with the naked eye, and it needs to use professional testing tools. For now,false seamless elbow often appears in the area below the diameter of DN600.
2. Molding process differences
The process of using seamless steel pipe and welded steel pipe is the same process. The difference is the welded elbow made of steel plate, through bending and different welding processes.
3. Performance and Usage
Seamless steel pipe elbow has better pressure capacity, strength is higher than welded steel pipe elbow. So it is widely applied in high pressure equipment, and thermal, boiler industries. Generally the welding seam of the welded steel pipe elbow is the weak point, the quality affect overall performance.
In general, welded steel pipe elbows can withhold 20% less working pressure than seamless ones. This reliability is the prime factor why people go for seamless steel pipe elbow. As a matter of fact, all the industrial pipelines are done with seamless pipe elbows only because the elbows undergo extreme thermal, chemical and mechanical workloads. Welded elbows are more preferred in aerospace, automobile and electronics industries where the budget is comparatively low, and so is the work pressure put on the pipeline.
4. Available Sizes differences
For most of seamless steel pipe elbow manufacturers in China, they produce original seamless pipe elbow sizes maximum OD in 24 inch, 609.6 mm.On the contrary, welded steel pipe elbow don’t have these limitations, sizes available from 1-1/2 inch 48.3mm to 100 inch 2540 mm.
5. Cost and prices
Usually the seamless steel pipe elbow cost is higher than welded steel pipe elbow, because the raw material, manufacturing equipment and processes. But sometimes by the market pressure, welded elbow is more expensive, so if you met this situation, don’t hesitate to purchase the seamless steel pipe elbow for the same dimensions.