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Pipe ID roughness
- Thread starter pipe15
- Start date
Max absolute roughness for slightly aged pipe is typically thought of as 0.0018 inches for hydraulic analysis. From the mills you should get in reality about 0.0010 inches. That could get worse if it corrodes in service, or it could .... actually get better .. as it ages.
It is not a specified parameter.
It is not a specified parameter.
You would have to obtain the roughness from the specific manufacturer of the pipe. If the roughness is not appropriate for your application, you would have to specify a subsequent cold or hot finishing.
Forged Seamless Pipe. Forged pipe is used for large-diameter, NPS 10–30 (DN 250–750), and thickness, 1.5–4 in (40–100 mm), pipe, where equipment availability and cost for other seamless grades are limiting. There are two processes available for the production of forged seamless pipe, namely, forged and bored pipe and hollow forged pipe.
Forged and Bored Seamless Pipe. In the forged and bored process a billet or ingot heated to forging temperature is elongated by forging in heavy presses or forging hammers to a diameter slightly larger than that of the finished pipe. After turning in a lathe to the desired outside diameter, the inside diameter is bored to the specified internal diameter dimensions. The resulting pipe can be made to very close tolerances. Sections 50 ft (15 m) long have been produced by this process.
Hollow Forged Seamless Pipe Erhardt Type Process. The Erhardt process (Fig. A5.7), developed by Heinrich Erhardt in Germany in 1891, consists of heating a square ingot to forging temperature, placing it into a circularly hollow die, and incompletely piercing it with a vertical piercing mandrel such that a cup shape is obtained. As a result of the piercing at forging temperature, the square ingot becomes the (circular) shape of the die. After reheating, the cup-shaped shell is mounted on a mandrel and pushed through a series of dies to the desired diameter and wall thickness, after which the cupped end is removed and the inside and outside pipe diameters are machined. This process is used for large-diameter and heavy-wall seamless pipe for boiler headers and main steam line piping. It can be applied to produce low and medium carbon steel pipe (ASTM A53, A106, A161, A179, A192, A210), stainless steel pipe (TP329, TP304, TP304L, TP321, TP347, TP316), and high nickel alloys (A333, A334).
Cold and Hot Finishing of Seamless Pipe and Tube. Pipe that has been produced by the Mannesmann plug-mill, mandrel mill, Ugine Sejournet, or Erhardt forging process can be used as hot finished seamless steel pipe or tube if the application does not require further finishing. If further finishing is required, the pipe or tube may be further reduced by a cold reduction process (Fig. A5.8). If the cold reduction processes are used, the reduced tube must be heat-treated in a furnace such as a bright annealing furnace or in a continuous barrel furnace. Subsequent to the heat treatment of the cold finished pipe, the pipe must pass through a straightening process which corrects any nonstraight sections caused in the pipe by the heat treatment of cold reduced pipe. The straighteners are either a series of rolls through which the pipes pass cold or a device which bends the pipe at discreet locations along the pipe. The resulting product is called cold finished seamless pipe or tube. In applications of tube to fossil fuel boilers, cold finishing is sometimes specified. Cold finishing improves the surface finish and dimensional accuracy. Some boiler manufacturers, however, consider the hot finished tube surface satisfactory and specify it as such because of its reduced cost.
Manufacturing of Metallic Pipe, Alfred Lohmeier
Forged Seamless Pipe. Forged pipe is used for large-diameter, NPS 10–30 (DN 250–750), and thickness, 1.5–4 in (40–100 mm), pipe, where equipment availability and cost for other seamless grades are limiting. There are two processes available for the production of forged seamless pipe, namely, forged and bored pipe and hollow forged pipe.
Forged and Bored Seamless Pipe. In the forged and bored process a billet or ingot heated to forging temperature is elongated by forging in heavy presses or forging hammers to a diameter slightly larger than that of the finished pipe. After turning in a lathe to the desired outside diameter, the inside diameter is bored to the specified internal diameter dimensions. The resulting pipe can be made to very close tolerances. Sections 50 ft (15 m) long have been produced by this process.
Hollow Forged Seamless Pipe Erhardt Type Process. The Erhardt process (Fig. A5.7), developed by Heinrich Erhardt in Germany in 1891, consists of heating a square ingot to forging temperature, placing it into a circularly hollow die, and incompletely piercing it with a vertical piercing mandrel such that a cup shape is obtained. As a result of the piercing at forging temperature, the square ingot becomes the (circular) shape of the die. After reheating, the cup-shaped shell is mounted on a mandrel and pushed through a series of dies to the desired diameter and wall thickness, after which the cupped end is removed and the inside and outside pipe diameters are machined. This process is used for large-diameter and heavy-wall seamless pipe for boiler headers and main steam line piping. It can be applied to produce low and medium carbon steel pipe (ASTM A53, A106, A161, A179, A192, A210), stainless steel pipe (TP329, TP304, TP304L, TP321, TP347, TP316), and high nickel alloys (A333, A334).
Cold and Hot Finishing of Seamless Pipe and Tube. Pipe that has been produced by the Mannesmann plug-mill, mandrel mill, Ugine Sejournet, or Erhardt forging process can be used as hot finished seamless steel pipe or tube if the application does not require further finishing. If further finishing is required, the pipe or tube may be further reduced by a cold reduction process (Fig. A5.8). If the cold reduction processes are used, the reduced tube must be heat-treated in a furnace such as a bright annealing furnace or in a continuous barrel furnace. Subsequent to the heat treatment of the cold finished pipe, the pipe must pass through a straightening process which corrects any nonstraight sections caused in the pipe by the heat treatment of cold reduced pipe. The straighteners are either a series of rolls through which the pipes pass cold or a device which bends the pipe at discreet locations along the pipe. The resulting product is called cold finished seamless pipe or tube. In applications of tube to fossil fuel boilers, cold finishing is sometimes specified. Cold finishing improves the surface finish and dimensional accuracy. Some boiler manufacturers, however, consider the hot finished tube surface satisfactory and specify it as such because of its reduced cost.
Manufacturing of Metallic Pipe, Alfred Lohmeier
LittleInch
Petroleum
38" 1.75 INCHES wt???
What are building - a super gun?
From this excellent post - it looks like 150 E-06 / 46 micron is as good as number as you'll get. I have seen people go and measure this on site after delivery and normally come up with about half that number.
Unless it's really important to you, I wouldn't normally specify it as a requirement, but if you want it really really smooth then go ahead.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
What are building - a super gun?
From this excellent post - it looks like 150 E-06 / 46 micron is as good as number as you'll get. I have seen people go and measure this on site after delivery and normally come up with about half that number.
Unless it's really important to you, I wouldn't normally specify it as a requirement, but if you want it really really smooth then go ahead.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
I did not realize there was any such thing as a "forged and bored pipe". Do you mean to say they forge a humongous round cylinder and then bore 80% of it away to make a pipe?
I would think the number of suppliers would be pretty limited, so contacting them would seem to be the solution.
I would think the number of suppliers would be pretty limited, so contacting them would seem to be the solution.
Wouldn't that be wasteful in 38 inch pipe? I don't think I'm buying this one.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
The actual roughness in service might not be the same roughness that is identified at the end of the fabrication process. In the case of P11, it is normally selected for either high temperature service( 790 -975 F) or it is selected due to its reduced propensity for FAC low accelerated corrosion. In both cases the in-service roughness may be worse than the post fab roughness due to either oxidation or erosion/corrosi0on.
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