1.Piping Introduction and Fundamentals
-
Upload
john-larry-corpuz -
Category
Documents
-
view
79 -
download
13
description
Transcript of 1.Piping Introduction and Fundamentals
-
1 PIPING INTRODUCTION
2014
SUMIT
PIPING INTRODUCTION
-
2 PIPING INTRODUCTION
INDEX
CODE 3
PIPING V/S PIPELINE 4
PRINCIPLES OF PIPING ENGINEER 4
STANDARDS 5
PLANT DISCIPLINE 5
PIPING FUNDAMENTALS 6
PIPE 6
PIPING ASPECTS 7
-
3 PIPING INTRODUCTION
PIPING INTRODUCTION AND FUNDAMENTALS:
Oil/gas refinery
Petrochemical plant
Chemical plant
Ammine plant
Alcohol plant
Pesticide plant
Textile plant
Cement plant
Hygienic plant: (s.s is used)
Pharmaceutical plant: more precaution is taken
Food plant:
Dairy plant
Chocolate plant
Pepsi/ coke plant
Green field project: to be constructing
Brown field project: working
ASME American society of mechanical engineering
Or
ANSI American national standard institute
CODE:
Definition: it consist of standards for design, fabrication, installation, testing and m/L
instructions
Complexity of process plant:
Fluid
Normal
Flammable
Toxic- H2
Viscous
Corrosive
-
4 PIPING INTRODUCTION
Temperature > 1000f
Pressure > 6000 psi
ASME 31.3: process piping code
ASME 31.1: power piping code
ASME 31.4: liquid transportation pipe lines
ASME 31.8: gas transportation pipelines
PIPING V/S PIPELINES
Piping system inside the plant only
Pipe line b/w 2 plants/ cities/ countries
PRINCIPLES OF PIPING ENGINEER:
1) Safety:
The piping system which is design and constructed should be safe (by using
codes and standards)
2) Constructability:
The piping system which is design should also be construct able
3) Operability : the piping system which is design and constructed should also be
operable
4) Maintainability:
The piping system which is design and constructed and operated should also
be maintained which requires placing the facilities in the area by following
their maintenance requirements.
Like: a valve during the operation may have maintenance requirement so it
should be located where it can be excess by the plant technician to reduce
maintenance time.
5) Economy:
The piping system which is design, constructed, operated and maintained will
should also be economical.
-
5 PIPING INTRODUCTION
STANDARDS:
These are documents prepared by professionals for the components which are to be
used in the market of piping system.
PLANT DISCIPLINES:
Process engg. ( chemical engg)
Piping engineer
Mechanical engg.
Civil engg
Electrical engg
Instrumentation engg
50%
25%
25%
PLANT
50% mechanical equipment
23 to 25 % piping
25 to 27 % civil,instrumental,electrical
-
6 PIPING INTRODUCTION
PIPING FUNDAMENTALS:
1) Drawings
Flow diagram
Block flow diagram
Process flow diagram
P & id
Utility flow diagram
Layouts
Isometrics
2) Equipment supports
3) Piping supports
4) Design calculation
5) Stress analysis- Caesar II
PIPE:
It is cylindrical shape structure used to transfer the fluid, solid or semi solids from one
pt. to another under pressure.
Fluid :
Liquids( water)
Gases( air)
Solids :
pellets( tablets)
powder ( cement)
semi solids:
slurry( crude oil, grease)
-
7 PIPING INTRODUCTION
PIPING ASPECTS:
1. Diameter:
IPS: ( iron pipe size)
It is dimensionless pipe designator (indicator) of pipe. It represents the
I.D of the pipe in inches.
Ex: IPS 6 I.D of the pipe is 6
NPS: ( nominal pipe size)
It is dimensional pipe designator of pipe. It represents O.D of pipe in
inches.
Ex: NPS 6OD of pipe is 6.625
NPS 14OD of pipe is 14
NB: ( nominal bore)
It is dimensional pipe designator of pipe. It represents OD of pipe in
mm.
Ex: NB 100 OD of pipe is 114 mm
NB 400OD of pipe is 400 mm
DN: ( diameter nominal)
It is dimensionless designator of pipe. It represents OD of pipe in mm.
Ex: DN 100 OD of pipe is 114 mm
DN 400 OD of pipe is 400 mm
NPS OD NB/DN
1 1.315 25
2 2.375 50
3 3.5 80
4 4.5 100
6 6.625 150
8 8.625 200
10 10.75 250
12 12.75 300
14 14 350
-
8 PIPING INTRODUCTION
Note:
Up to NPS 12 , OD > NPS
From NPS 14, OD = NPS
Note:
Smallest pipe size : 3mm or 1/8
Max pipe size : 60 ( 5 feet)
Note:
Pipe of size < NPS 2 are called small bore pipes
Pipe of size > NPS 2 are called big bore pipes
Highest of small bore size = 1.5
2. Wall thickness:
It is represented by following terms.
(i). Schedule no. ( SCH)
(ii). Pipe weight designation
(i) SCH:
It is a no. which has standardize thickness as per the standards
Sch no. range :
5, 5s, 10, 10s,20,20s,30,40,60,80,100,120,140,160
Sch no. without s is for CS and AS
Sch no with s is for ss
Ex: NPS 6 SCH 10
NPS 6 SCH 10s
(ii) Pipe weight designation:
It is alternative way for representing pipe thickness
STD standard weight thickness
XS/XH extra strong /extra heavy
XXS/XXH double extra strong/ double extra heavy
Ex: NPS 6 SCH STD
STD SCH 40 for diff. pipe size
XS SCH 80
-
9 PIPING INTRODUCTION
i) t = P do/ 2(SEW + PY)
ii) tm = t + A
iii) = tm 12.5 % mill tolerance
iv) Sch thickness from standards
Here:
t = thickness
P = internal pressure
Do = outer diameter
S = basic allowable stress from code
E = longitudinal weld joint quality factor from code
W = weld joint stress reduction factor from code
Y = coeff. For m/L from code
tm = min thickness
A = sum of corrosion, erosion, thread depth allowance (TDA)
= nominal thickness
3. Pipe length :
Single random length : 6 m ( 20 feet)
Double random line : 12m ( 40 feet)
Customize length : as per customer requirement ( for pipelines)
-
10 PIPING INTRODUCTION
4. Pipe ends:
Plane ends: for small bores
Screwed / threaded ends: for small bores
Straight
Tapered : used in process piping and also known as NPT(
national standard tapper pipe thread )
Beveled ends: 37.5 is most commonly used bevels.
5. Pipe joining methods:
(i). Screwed joining method
(ii). Socket weld method(sw)- for plane ends pipes
(iii). Butt weld method(bw)
-
11 PIPING INTRODUCTION
(i) Screwed joining method:
It requires an external ad for joining two pipes.
Advantages:
It can be easily made on the site
It can be used where welding is not permitted due to fire hazard
Disadvantages:
It is not used for big bores and high pressure and temp. Lines.
There is joint leaks
A seal weld can be used for threaded joint but the code doesnt
allow to consider the welding strength as the joint strength
(ii) Socket weld joining method:
Gap of 1/16 or 1.5 mm is to be maintain to accommodate pipe
thermal expansion
Two circumferential weld is done
-
12 PIPING INTRODUCTION
Advantages:
End preparation is not required
Alignment if end is not required
The welding is less time consuming
Disadvantages:
Not used for big bores and high press. and temp. lines
1.5 mm gap pocket fluid is not permitted by code for corrosive
and abrasive fluids.
(iii) Butt weld method:
It is generally used for joining big bore pipes
Root gap for proper weld preparation , mostly 75
Advantages:
It is the best way for joining big bore, high temp and pressure
lines
The joint is reliable and leak proof
The joint can be radiograph
-
13 PIPING INTRODUCTION
o NDT techniques
Radiography
VT
MPT
DPT
RT: to find weld defects
UT: to find the flow dimension
Radiography:
it is the method in which welding flaws (defects) are
found by passing radiation through the welding by
placing a source ( radiation emitter) (ex:cobalt)
whose radiation forms a lighter and bitter shape of
image on film wrapped on welding from pipe
outside which helps in finding the defects in
welding.
Disadvantages
End preparation is necessary
Alignment of ends is necessary
Welding is more time consuming than the socket weld
A backing ring is required to avoid weld penetration to pipe ID
o Backing ring shapes:
Circular
Square
Rectangular
o M/L of backing ring:
Ferrous or non ferrous
Consumable or non consumable
6. Pipe manufacturing methods:
(i). Seamless ( E=1)
(ii). ERW(electric resistance weld)
(iii). EFW(electric fusion weld)
(iv). FBW(fusion butt weld)
(v). SAW(submerge arc weld)
(vi). DSAW(double submerge arc weld)
Ex: NPS 8 SCH 40 ERW
-
14 PIPING INTRODUCTION
Note: other than seamless, all other methods (E< 1)
7. Piping grades:
(i). Carbon steel :
Max temp : 800f( 427c)
Max carbon content : 0.35 %
Grades:
A, B, C
C is better than A & B
-
15 PIPING INTRODUCTION
Ex:
ASTM A53 GR A for ambient condition
ASTM A53 GR B for high temp
ASTM A106 GR B for high temp
ASTM A106 GR C for high temp
A53 is most commonly used carbon steel m/L
ASTM : American society for testing & m/L
Note:
Killing steel:
Killing is the process in which oxygen is removed by adding aluminum (Al2O3) and
manganese (Mno) which can be used for temp beyond 8000 f
(ii) Alloy steel:
Main alloy elements Cr,Mo
Max temp 1200f
Grades:
P1,P2,P5,P11,P12,P22
Ex:
ASTM A335 Gr P1
ASTM A335 Gr P11
ASTM A335 Gr P12
(iii) Stainless steel:
Main alloy elements: Cr,Ni
Called as austenite ss due to the presence of Ni
Carbon content : 0.08 %
Max temp: 1600 f
Note:
It is used for ambient temp also for corrosive fluid
Grades:
304, 304L, 316, 316L, etc
Ex:
ASTM A312 TP 304
ASTM A312 TP 304L
-
16 PIPING INTRODUCTION
ASTM A312 TP 316
ASTM A312 TP 316L
TP- tabular product
L- Low carbon content: 0.03 % max
Note:
At high temp. carbon present in the ss reacts with cr to form
crc(chromium carbide) due to which the white surface layer of
chromium(cr) is depleted, making steel prom to corrosion, to
avoid this either low carbon ss or ss with stabilizer like
chromium , titanium is used which have more attraction and
reaction to carbon than chromium.
Most commonly used ss is 304 with 18 %Cr and 8 %
Ni
8. Pipe symbols:
Rise symbol:
It is for pipe going up/coming towards us.
-
17 PIPING INTRODUCTION
Drop symbol:
It is for pipe going away from us/dropping/ going down
Incomplete circle with pipe going inside it.
Single line drawing symbol:
In this the pipe is drawn with solid central line, this type is used up to
size 6 inch or 12 inch
Double line drawing symbol:
In this type the pipe is drawn in double line or the actual size of pipe is
drawn to scale with the chain dotted central line. (CL)
-
18 PIPING INTRODUCTION
Joint symbols:
Threaded joints
Socket weld joint(SW)
Butt weld joint(BW)
Note: