Dimentional Standard for Carbon Steel Pipes(Welded & Seemless)
ASME B 36.10
Dimentional Standard for Stainless Steel Pipe (Welded & Seemless)
ASME B 36.19
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders, masses of small solids.
There are three processes for metallic pipe manufacture.
1-Centrifugal casting of hot alloyed metal is one of the most prominent process. Ductile iron pipes are generally manufactured in such a fashion.
2-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.
3-Welded (also Electric Resistance Welded ("ERW"), and Electric Fusion Welded ("EFW")) pipe is formed by rolling plate and welding the seam.
Note:
Seamless pipes are made using extruction process. There will be no seam on the periphery of tube which can take more pressure.
But the ERW tube is made from a plate rolling down to a pipe form and then finally welded at seam. Hence the pipe is weak at welded region so incapable od taking more pressure.
So all the pressure parts tubes in boiler plants are made up of seamless tubes.
Pipe Size Designation
Pipe sizes are specified by a number of national and international standards.
API 5L ………………………….......in USA
ANSI/ASME B36.10M………….in USA
ANSI/ASME B36.19M ……….. in USA
BS 1600 ………………………........in UK & Europe
BS EN 10255 ………………....…..in UK & Europe
JIS …………………………........…..in Japan
Two most popular common methods for designating pipe outside diameter (OD).:
The North American method
NPS ("Nominal Pipe Size") and is based on inches also known as NB ("Nominal Bore").
The European method
DN ("Diametre Nominal" / "Nominal Diameter") and is based on millimetres. Designating by OD-outside diameter
Two most common methods for designating Wall thickness & Weight.
Steel Pipe Size based on Sch ( read as Schedule )
The wall thickness were like- Sch 40, 80, 160. For example, Sch 20 pipe is even thinner than Sch 40, but same OD
The Iron pipe size (IPS)
the wall thickness were like- Standard Wall (STD), Extra Strong (XS), and Double Extra Strong (XXS)
Other Old system are
Ductile Iron Pipe Size (DIPS), which generally has larger ODs than IPS.
Plastic Irrigation Pipe(PIP) PIP comes in pressure ratings of 22 psi (150 kPa), 50 psi (340 kPa), 80 psi (550 kPa), 100 psi (690 kPa), and 125 psi (860 kPa)
Copper Tube Size (CTS)
Plastic tubing, such as PVC and CPVC, for plumbing applications also has different sizing standards
NOTES:
For pipe sizes less than NPS 14 inch /DN 350, both methods give a nominal value for the OD that is rounded off and is not the same as the actual OD.
Piping Class Rating.
The piping rating must be governed by the pressure-temperature rating of the weakest pressure containing item in the piping.The weakest item in a piping system may be a fitting made of weaker material or rated lower due to design and other considerations.It is usual industry practice to classify the pipe in accordance with the pressure temperature rating system used for classifying flanges.
Some Commonly Used Materials: Stainless Steel, Carbon Steel, Alloy Steel
Other Materials : Monel, Nickel, Inconel, Hastalloy, Copper, Brass, Bronze, Titanium, Tantalum, Bismuth,Aluminium, High Speed Steel, Zinc, Lead, Etc.
Some Commonly Used Designated Piping Materials:
Stainless Steel : ASTM A312 TP 304/ 304L/ 304H/ 316/ 316L/ 317/ 317L/ 321/ 310/ 347/904L/ etc.
Carbon Steel : ASTM A53 GR. B/ A106 GR. B/ API 5L GRADE B/ API 5L GR. X42/46/52/56/60/65/70 / A333 GR. 3/ GR. 6/ etc.
Alloy Steel : ASTM A335 GR. P1/ P5/ P9/ P11/ P22/ P91/ etc.
Pipe Lengths
single random
double random
longer than double random
cut lengths
Single Random Length : Single random pipe length is usually 18-25 feet plain end or 18-22 feet threaded and coupled pipes.
Double Random Lengths : Double random length pipes are made between 38-40 feet.
Longer than Double Random: The length of longer than double random pipes are more than 38-40 feet.
Cut Lengths: Cut length pipes are made in fixed lengths within +/- 1/8 inch. Some pipe is available in about 80-ft lengths.
Pipe Ends
Bevel End (BE)
Bevel Both Ends (BBE)
Bevel Large End (BLE)
Bevel One End (BOE)
Bevel Small End (BSE)
Bevel for Welding (BFW)
Buttweld Ends (BE)
End of Pipe (EOP)
Flange One End (FOE)
Plain End (PE)
Plain End Beveled (PEB)
Plain One End (POE)
Plain Both Ends (PBE)
Screwed End (SE)
Screwed Both Ends (SBE)
Screwed One End (SOE)
Socket Weld End (SWE)
Thread Both Ends (TBE)
Thread End (TE)-
Note:A threaded connection is often designated by a T as in TE for threaded end. When describing a nipple, it would be used as TOE or TBE for threaded one end or threaded both ends.
Thread Large End (TLE)
Thread One End (TOE)
Thread Small End (TSE)
Threads Only (TO)
NOTES:
For pipe sizes less than NPS 14 inch /DN 350, both methods (North American method-NPS and Europian method-DN)give a nominal value for the OD that is rounded off and is not the same as the actual OD.
After 14 inch the actual OD of the pipe will be same as there respective inches of the pipe size.
