design of pipe joints
DESCRIPTION
Shankar SehgalChandigarhTRANSCRIPT
Design of Pipe Joints
By:Er. Shankar Sehgal
Faculty of Mech. Engg., UIET,Panjab University, Chandigarh
Website: http://shankarsehgal.weebly.com
Pipes Materials
• C.I.– Low resistance to shocks and water hammering– Up to 0.7 Mpa only– Water and sewage systems
• Wrought Iron– Mass transfer of steam, air and oil
• Steel– Petroleum industry– Up to 4 Mpa and 440°C
• Brass– Pressure lubrication systems
Design of pipes
WhenD/t < 20σ/p < 6
WhenD/t > 20σ/p > 6
Design of pipes
• For C.I., Wrought Iron, C = 9 mm
• For steel, brass, C = 3 mm
Design of pipes
Design of pipes
Socket or Coupler Pipe Joint
Nipple Pipe Joint
Union Pipe Joint
Spigot and Socket Pipe Joint
Expansion Pipe Joint
Copper Corrugated Expansion Pipe Joint
Used for short length pipes only
Sleeve and Socket Type Expansion Pipe Joint
Sleeve and socket can have relative movements along the axis
Circular Flanged Pipe Joint
Circular Flanged Pipe Joint
Used for pressures up to 2 MPa
Design of Circular Flanged Pipe Joint
• Considering tensile failure of bolts:
• Circumferential pitch of bolts:
2
21
4
4
cdn
pD
AF
nD
p pc
Design of Circular Flanged Pipe Joint
• Bending failure of flange:
12
4
2
3
21
ff xt
yn
pD
tIM
y
Oval Flanged Pipe Joint
Used for pressures up to 15 MpaNumber of bolts = 2
Design of Oval Flanged Pipe Joint
• Considering tensile failure of bolts:
2
221
2
4
244
2/__
cd
pDDpD
AForcePackingForceFluid
AF
Design of Oval Flanged Pipe Joint
• Bending failure of flange:
12
24
2
3
21
ff xt
epD
tIM
y
Square Flanged Pipe Joint
Number of bolts = 4
Design of Square Flanged Pipe Joint
• Considering tensile failure of bolts:
2
221
2
4
244
2/__
cd
pDDpD
AForcePackingForceFluid
AF
Design of Square Flanged Pipe Joint
• Bending failure of flange across section AA:
Design of Square Flanged Pipe Joint
• Bending failure of flange across section AA:
12
2
____..24
42
2
32
1
21
ff ttDL
pressurewatertodueMBLpD
tIM
y
Seals
• To prevent leakage of fluids due to overpressure in an assembly where mating surfaces have relative motion
• Functions are:– To seal in oil, grease etc.
– To seal out dirt, contaminants etc.
– To maintain applied pressure or vacuum
Gaskets
• To create and maintain a barrier against flow of fluid across mating surfaces placed in an assembly relatively at rest.– Metallic gaskets
• Lead• Copper• Brass• Aluminium• Low Carbon Steel
– Non-metallic gaskets• Paper• Leather
Thank You