Presentation on Pipes

EPCM – ENGINEERING PROCUREMENT & CONSTRUCTION MANAGEMENT

PRESENTATION ON PIPES.

Presented By :-

Ananda Ahirrao.

Sandip Boricha.

Sachindev Bhudiya.

Satishkumar Patel.

GET’s

EPCM Piping Department.



General Introduction of PIPES & TUBES.Pipes :- The purpose of a pipe is to transport of fluids like

water, oil and many other products, the most import pipe property is the capacity, or in reality, the inside diameter of the pipe. The nominal diameter of a pipe is therefore related to the inside diameter.



Tubes :-

The nominal dimensions of tubes are based on the outside diameter. If we look at Copper Tubes, the outside diameter of a 2" tube is 2.125", relatively close to 2". The inside diameter of a tube will depend on the thickness of

the tube. The thickness is often specified as a gauge.



Comparison between Tube & Pipe. Tube :-1. Lower thickness & Higher ductility.2. Specified by O.D. & thickness in SWG.3. Uniform thickness means less chance of failure.4. Lower roughness factor & pressure drop.5. Normally used in HEs & coils for Heat Transfer.6. Limitation in Sizes. 7. Manufactured in circular, square or rectangular

shapes.



Pipes :- 1. Lower ductility, Higher M.I., & high residual

stress.

2. Specified by Nominal Bore & Thickness by Schedule.

3. Higher roughness factor & higher pressure drop.

4. Normally used in straight length for fluid transfer.

5. No limits in sizes.



NPS(NORMAL PIPE SIZE):-

NPS is a dimensionless designator of pipe size. It indicates the standard pipe, followed by specific size designation no. without an inch symbol.

ex. NPS 2 indicates a pipe whose outside diameter is 2.375

Note:- NPS is loosely related to the inside diameter inches for NPS 1/8 to 12. For NPS 14 and larger the NPS

is equal to the outside diameter (OD). DN(DIAMETRE NOMINAL):-

Pipe sizes are specified in metric unit.



Diameter Nominal- DN -(mm)

Nominal Pipe Size- NPS -

(inches)

6 1/8

8 ¼

10 3/8

15 ½

20 ¾

25 1

32 1 1/4

40 1 ½

50 2



SCH NO. (schedule number):-

The term schedule no. was invented to specify nominal

wall thickness.

As the schedule no. increases the wall thickness of pipe

also increases.

Pipe size

(inch)

Outer

diameter

Sch

No.

Wall thickness

(inches)

2 2.375 5s

10s

40s

.065

.109.154



Various Piping Types :-

1. Power Piping.

2. Fuel Gas Piping.

3. Chemical Plant & Petroleum Refinery Piping.

4. Liquid Petroleum Transportation Piping.

5. Refrigeration Piping.

6. Nuclear Power Piping.

7. Gas Transmission & Distribution Piping.


PRESENTATION ON PIPES

TYPES OF PIPES:

(1) Based on the method of manufacturing pipes could be

classified.

1.Electric resistance welded.

2.Furnace butt welded, continuous welded.

3.Electric fusion welded.

4.Double submerged arc welded.

5.Spiral welded.

(2). Seamless pipes.



General Consideration for Selection of Pipe Material.

Possible exposure to fire. Ability of thermal insulation to protect the pipe from

fire. Susceptibility of the pipe to brittle failure, or failure

from thermal shock. Susceptibility of the piping material to crevice

corrosion in stagnant confined areas.



1.ASME B 36.10:

This std. is applicable for welded and seamless wrought steel pipe.

2.ASME B 36.19: This std.is specifically covers stainless steel. The specification no 36.10 indicates a table data no

where classification ,use and properties are correlated. Other standards are ANSI,ASTM,DIN,API, ISO all

these standards covers the information regarding pipe design specifications, materials, components, supports, fabrication, inspection and testing.



The selection of piping materials for right application requires knowledge of corrosion properties, strength and engineering characteristics, relative cost and availability.

The main process considerations in material selection are the corrosion properties of fluid, the pressure temp condition of the service and the nature of service.

The following are the material of construction for piping.

Common metals used in Pipe Manufacturing Carbon steel and low- and intermediate-alloy steels. High-alloy (stainless) steels. Nickel nickel-base alloys.



Aluminum and aluminum alloys. Copper and copper alloys.

PIPE MATERIALS:

The most commonly used material standards for

the pipes are listed below.

1. ASTM A53 - Welded and seamless steel pipe, black

and galvanized .

2. ASTM A106 - Seamless CS pipe for high temp

services.

3. ASTM A312 - Seamless and welded austenitic ss

pipes.

4. ASTM A333 - Seamless and welded steel pipe for

low temp service.



5. ASTM A335 -Seamless ferritic alloy steel pipe for high temp s/c. metal no. Pipe grade 1/2Cr-1/2moly SA-335 P2 1Cr-1/2moly SA-335 P12 1/4Cr-1/2mo-SI SA-335 P11 21/4Cr-1mo SA-335 P22 5Cr-1mo SA-335 P5 9Cr-1mo SA-335 P9 9Cr-1mo-v SA-335 P9

6. ASTM A409 -Welded large dia. austenitic steel pipe for corrosive or temperature service. 7. ASTM A671 -Electric fusion welded steel pipe for atmospheric and low temperature service.

8. API 5L -Line pipe.

9. IS 1239 -Steel pipes for general purposes.

10. IS 3589 -Steel pipes for general services.



Non metals used for Pipe Manufacturing :- Thermoplastics :- Acrylonitrile-butadiene-styrene (ABS). Cellulose acetate butyrate (CAB). Polyethylene. Polypropylene. Poly Vinyl Chloride. Chlorinated Poly Vinyl Chloride. Nylon. Glass, ceramic, Cement.



2. Reinforced thermosetting resins :- Epoxy, glass-fiber-reinforced. Polyester, glass-fiber-reinforced. Furan, glass-fiber-reinforced. Furan, carbon-reinforced.



Manufacturing Methods For Pipes :-1. Welding Process :- SAW. Spiral Welding. ERW. JCO/UO.2. Seamless Pipes :- Plug Mill. Mandrel Mill. Extrusion.3. Casting Process :- Centrifugal Casting. Continuous Casting.



Submerged Arc Welding :-

1. Longitudinally Welded SAW Pipes.

The most popular process for large diameter pipe uses a longitudinal seam weld. Double submerged arc welded (DSAW) pipe is welded pipe whose longitudinal butt joint is welded in at least two passes, one of which is on the inside of the pipe. Finished pipes are normally 40 feet (12 m) and occasionally 60 feet (18 m) long, depending on the capacity of the pipe mill . This process is shown in the graphical view.



2. Spiral Welded Pipes :-

Spiral weld construction allows large diameter pipe to be produced from narrower plates or skelp. In this process, narrow strips of steel sheet are helically wound into cylinders. The edges of this strip can either be butting or overlapping and are welded by any of several electric arc-welding processes.



3. Electric Resistance Welding :-

Pipes having longitudinal butt joint wherein coalescence is produced by the heat obtained from resistance of pipe to flow of electric current in a circuit & by application of pressure. ERW pipe is produced by cold forming. This type of steel pipe is used in large quantities as line pipe for transporting petroleum and gas. The process of making ERW pipe, is shown in the graphical view.

4. JCO/UO :-

UO pipe is usually large in diameter and produced one piece at a time by forming plates. The plate is first pressed into a U shape by the U-press, and then into an O shape by the O-press. Then it is welded.



Seamless Pipes :-

1. Plug Mill :-

This process is used to make larger sizes of seamless pipe, typically 6 to 16 inches diameter. An ingot of steel weighing up to two tons is heated to 1,300 °C and pierced. The hole in the hollow shell is enlarged on a rotary elongator. An internal plug approximately the same diameter as the finished diameter of the pipe is then forced through the bloom. The bloom containing the plug is then passed between the rolls of the plug mill. Rotation of the rolls reduces the wall thickness. The tube is rotated through 90° for each pass through the plug mill to ensure roundness. The tube is then passed through a reeling mill and reducing mill to even out the wall thickness and produce the finished dimensions.



2. Mandrel Mill :-

This process is used to make smaller sizes of seamless pipe, typically 1 to 6 inches diameter. The ingot of steel is heated to 1,300 °C and pierced. A mandrel is inserted into the tube and the assembly is passed through a rolling mill. Unlike the plug mill, the mandrel mill reduces wall thickness continuously with a series of pairs of curved rollers set at 90° angles to each other. After reheating, the pipe is passed through a multi -stand stretch-reducing mill to reduce the diameter to the finished diameter.



3. Extrusion Process :-

This process is used for small diameter tubes only. The bar stock is cut to length and heated to 1,250 °C before being sized. The billet is then extruded through a steel die. After extrusion, the final tube dimensions and surface quality are obtained with a multi-stand reducing mill.



Casting Process :-

1. Continuous Casting :-



2. Centrifugal Casting :- To make DISP (Ductile Iron Sponge Pipe).

Hot Zone :- Centrifugal Casting. External Zinc Coating for Galvanizing.

Cold Zone :- Hydraulic Test for Leakage Testing. Internal Cement Coating. To the Furness. External Bitumen Coating.





TESTING OF PIPES Why tests are required?

– To meet specifications

– To detect imperfection of product

• Cracks, surface and sub-surface flaws

– To prevent hazards in refinery

– A purchaser is interested to know nature of imperfection, which can

be detected by test, to discuss it with manufacturer of pipes.



Three tests generally used for pipes are

• ULTRASONIC TEST

• REDIOGRAPHIC TEST

• HYDROSTATIC TEST



ULTRASONIC TEST

It is to detect surface, sub-surface and dimensional flaws.

PROCEDURE

It needs– Ultrasonic transducer .– Receiver

• Pulse-echo

• Through transmission

It can detect– Material defect – cracks, inclusion.– Dimensional changes – thickness.


PRESENTATION ON PIPESREDIOGRAPHIC TEST

It is to detect internal defects in material by exposure to x-ray or gamma rays radiation.

PROCEDUREArrangement



X-ray tube and camera are separated on the pipe by an angle of 180º.

Defects are detected by difference in radiation absorption in material as seen on camera or photographic film.

X-ray tube and camera moves line to line around the circumference to acquire the radiographic image on camera or photographic film.



CAMERAS ARE BETTER– It can capture image digitally.– Digital image will not deteriorate with time.

High quality films can also give images of higher quality.



X-ray and Gamma rays– Difference is only in their source of origin.– X-ray produced by x-ray generator and gamma by radioactive

atoms.

LIMITATION OF TEST– Crack contrast in relation to crack location.– Only parallel transmission to the crack plane provides a sufficient

contrast.– X-ray and gamma ray can not detected by human senses.



HYDROSTATIC TEST

It is to detect cracks and manufacturing flaws.

PROCEDURE

– Pipe is located and filled with incompressible fluid.

– Predefined pressure built up for known time.

– Testing pressure should be more then max. operating pressure.

– Readings on instruments.

– Physical and visual inspection.



Pressure calculation

P = 2St / D

Where, P= Hydrostatic test pressure

S= Pipe wall stress

t= Specified nominal diameter

D= Specified outside diameter

– Testing pressure also depends on size of pipe to be tested.

– As per ASTM standard

2500 psi for NPS < or = 3.

2800 psi for NPS > 3.

Testing time should not less then 5 seconds and it also depends on length of pipe.


THANK YOU

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