2. Contents
• Introduction
• Elements of Gating System
• Functions of gating system
• Defects occurring due to improper design of gating system
• Types of Gates
• Pouring Time
• Gating Ratio
• Guidelines for Designing Gating System
• Review of papers
• Conclusion
• References
2
3. Introduction
• Mould is used for producing a casting. Molten
metal is conveyed into the mold cavity by using
Gating system.
• In casting process, gating system plays an
important role to produce a high quality casting.
• A poorly designed gating system results in
casting defects.
• A gating system controls mould filling process.
The main function of gating system is to lead
molten metal from ladle to the casting cavity
ensuring smooth, uniform and complete filling.
3
4. Elements of Gating System
• Pouring Cup
• Sprue
• Sprue well
• Cross-gate or Runner
• Ingate or Gates
4
5. Pouring Cup
It is the funnel-shaped opening, made at the top of the mold. The main purpose
of the pouring basin is to direct the flow of molten metal from ladle to the
sprue.
Sprue
It is a vertical passage connects the pouring basin to the runner or ingate. It is
generally made tapered downward to avoid aspiration of air. The cross section
of the sprue may be square, rectangular, or circular.
Sprue well
It is located at the base of the sprue. It arrests the free fall of molten metal
through the sprue and turns it by a right angle towards the runner.
Runner
It is a long horizontal channel which carries molten metal and distribute it to
the ingates .It will ensure proper supply of molten metal to the cavity so that
proper filling of the cavity takes place.
Gates
These are small channels connecting the mould cavity and the runner.The
gates used may vary in number depends on size of the casting.
5
6. Functions of gating system
• A good gating system should help easy and
complete filling of the mould cavity.
• It should fill the mould cavity with molten
metal with least amount of turbulance.
• It should prevent mould erosion.
• It should establish proper temperature gradient
in the casting.
• It should promote directional solidification.
• It should regulate the rate of flow of metal into
the mould cavity.
6
7. Defects occurring due to improper
design of gating system
• Oxidation of metal
• Cold shuts
• Mould erosion
• Shrinkages
• Porosity
• Misruns
• Penetration of liquid metal into mould walls.
7
8. Types of Gates
• Depending upon the orientation of the parting plane.
– Horizontal Gating System
– Vertical Gating System
• Depending upon the position of ingate(s), horizontal
gating system.
– Top Gating System
– Bottom Gating System
– Parting-line Gating System
8
10. Pouring Time
• Pouring rate is nothing but the time taken for filling the
mould cavity by a known quantity of metal i.e., Pouring
time can be used as an index to determine the pouring rate.
• When molten metal is being poured into the mould at a very
fast rate, mould erosion, rough surface, excessive shrinkage
may takesplace.
• When the pouring rate is very low, the complete filling of
the mould is not assured and may result in excessive drop in
the molten metal temperature.
• This result in casting defects such as cold shut, misrun etc.,
• In order to avoid this, it is necessary to arrive at the correct
rate of pouring of metal into the mould cavity.
• The type of metal, size and shape of the casting decide the
pouring rate.
10
11. Gating Ratio
Gating ratio refers to the relation between area of the choke
to total area of runner total area of Ingates. Mathematically, it can
be written as Ac: Ar: Ag .
The gating system completely controls the molten metal
flow. Gating systems can be classified as Pressurised system and
Unpressurised system.
Gating ratio depends on the nature of the molten metal.
• Pressurized system is used for reactive metals like magnesium
alloy etc. Unpressurised gating system is used for normal metals
such as brass, steel, aluminium alloy, etc.
• A Gating ratio such as 1:2:1 or 1:0.75:0.5 refers to pressured
system; whereas the gating ratio such as 1:2:2 or 1:3:3, 1:1:3,
refers to unpressurised gating system.
11
12. • Pressurized system is referred to as “Gate control
System”, since ingates controls the flow of metal.
• Unpressurised system is referred to as “Choke Control
System”, since the choke controls the flow of metal.
• In the pressurized system high metal velocity occurs
and results in turbulence. In the case of unpressurised
system, turbulence is produced and streamline flow is
induced.
• Pressurized System Consumes less metal and yield is
more. Unpressurised system consumes more metal and
the yield will be slightly lowered.
• In the case of pressurized system, the system will
always be full of liquid metal . In the case of
unpressurised system flow is not full.
12
13. Guidelines for Designing Gating System
• The size of the sprue fixes the flow rate. The amount of molten
metal that can be fed into the mold cavity in a given time
period is limited by the size of the sprue.
• The sprue should be located at certain distance from the gates
so as to minimize velocity of molten metal at ingates.
• Sprue should be tapered by approximately 5% minimum to
avoid aspiration of the air and free fall of the metal.
• Ingates should be located in thick regions.
• Locate the gates so as to minimize the erosion of the sand
mold by the metal stream. This may be achieved by orienting
the gates in the direction of the natural flow paths.
• Multiple gating is frequently desirable. This has the advantage
of lower pouring temperatures, which improves the
metallurgical structure of the casting. In addition, multiple
gating helps to reduce the temperature gradients in the casting.13
14. Conclusion
To reduce warpage proper gating system
plays a major role.
Optimized gating system improving casting
quality and increasing casting yield.
Optimum gating position leads to sound
casting. Proper gating framework are essential
to secure quality of casting.
14
15. References
• Review on Casting Defect: Warpage Surabhi Pareek1 V.S.Khangar2 ,
1Student M. Tech (CAD/CAM) 2Assistant Professor 1, 2Department of
Mechanical Engineering 1, 2GHRCE an Autonomus Institute, Nagpur-
420016, India
• Gating system design for warpage reduction 1Surabhi Pareek,
2V.S.Khangar 1Student M.Tech CAD/CAM, GHRCE, Nagpur- 420016,
India 2Assistant professor, GHRCE, Nagpur- 420016, India
• Numerical optimization of gating system parameters for a magnesium
alloy casting with multiple performance characteristics Zhizhong
Suna,∗, Henry Hua, Xiang Chenb a Department of Mechanical,
Automotive & Materials Engineering, University of Windsor; Windsor,
Ontario, Canada N9B 3P4 ,b Department of Electrical & Computer
Engineering, University of Windsor; Windsor, Ontario, Canada N9B
3P4hetiya
15
16. • A review on optimization of gating system in metal casting
sandeep singh1, lakhwinder pal singh2 & gurudutt sahni3 1
Research Scholar, Department of Industrial and Production
Engineering, National Institute of Technology Jalandhar, Punjab,
India 2Assistant Professor, Department of Industrial and Production
Engineering, National Institute of Technology Jalandhar, Punjab,
India 3 DGM &HOD, CE, PE, Design, Drawing and Development,
Leader Valves Ltd, Jalandhar, Punjab, India
• A Review on Optimization of Gating System for Reducing
Defect Swapnil A. Ambekar1 Dr. S. B. Jaju2 1 M.Tech Student,
Department of Mechanical Engineering, GHRCE , Nagpur 2 Dean,
R&D Department, Department of Mechanical Engineering, GHRCE
, Nagpur.
• Design and Analysis of Gating and Risering System for Casting of
Ball Valves ,P. G. Panchal, S. J. Joshi and N. D. G
16
18. S.No Title Author Published Workdone Remarks
1 Casting Defect:
Warpage
Surabhi Pareek1
V.S.Khangar2
IJSRD - Vol. 3, Issue
02, 2015 | ISSN
(online): 2321-0613
Casting produced by
foundry with distortion as
a major defect was
analyzed and identified
solution for its cause.
To reduce warpage proper
gating system plays a major
role with the help of casting
simulation technology to
reduce the lead time and
improve productivity
2 Numerical
optimization of
gating system
parameters for a
magnesium alloy
casting with
multiple
performance
characteristics
Zhizhong Sun,
Henry Hu, Xiang
Chen
journal of materials
processing
technology 1
9 9 ( 2 0 0 8 ) 256–
264.
Used an
optimization
method for design
of a casting based
on the Taguchi
method for
multiple
performance
characteristics.
The simulation results
indicated that gating system
parameters significantly
affect the quality of the
magnesium casting.
3 Gating system
design for warpage
reduction
Surabhi Pareek,
2V.S.Khangar
1Student M.Tech
CAD/CAM,
GHRCE, Nagpur-
420016, India
ISSN(O):2393-9877,
ISSN(P): 2394-2444,
Volume 2,Issue 4,
April- 2015
In this work AUTOCAST
software has been used
for designing proper
gating system .
Optimum riser position leads
to sound casting. A proper
gating system design with
the help of casting
simulation
software helps to eliminate
defects at large.
Review of papers
18
