# How to Calculate and Solve for Rated Static Head | Design of Gating System

The image above represents rated static head. To calculate rated static head, three essential parameters are needed and these parameters are Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity (H), Height of the Casting System from its top (P) and Height of the Casting (C).

### The formula for calculating rated static head

HsÂ = H –Â P2Â /Â 2C

Where:

H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity
P = Height of the Casting from its Top
C = Height of the Casting

Let’s solve an example;
Find the rated static head when the height of the sprue from its top to the point of metal entry into the mould cavity is 9,the height of the casting from its top is 5 and the height of the casting is 11.

This implies that;

H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity = 9
P = Height of the Casting from its Top = 5
C = Height of the Casting = 11

HsÂ = H –Â P2Â /Â 2C
HsÂ = 9 –Â 52Â /Â 2 x 11
Then, HsÂ = 9 –Â 25Â /Â 22
Hs = 9 – 1.136
Hs = 7.86

Therefore, theÂ rated static headÂ isÂ 7.86 m.

#### Calculating the Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity when the Rated Static Head, Height of the Casting System from its Top and the Height of the Casting are Given

H = Hs +Â P2Â /Â 2C

Where;

H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity
P = Height of the Casting from its Top
C = Height of the Casting

Let’s solve an example;
Find the height of the sprue when the rated static head is 25, the height of the casting system from its top is 8 and the height of the casting is 4.

This implies that;

Hs = Rated Static Head = 25
P = Height of the Casting from its Top = 8
C = Height of the Casting = 4

H = Hs +Â P2Â /Â 2C
H = 25 +Â 82Â /Â 2 x 4
So, H = 25 + 64Â /Â 8
H = 25 +Â 8
H = 33

Therefore, theÂ height of the casting system from its topÂ isÂ 33.

#### Calculating the Height of the Casting System from its Top when the Rated Static Head, the Height of the Sprue from its Top to the Point of Metal Entry into Mould Cavity and the Height of the Casting are Given.

p = – âˆš(Hs – H) x 2c

Where;

P = Height of the Casting from its Top
H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity
C = Height of the Casting

Let’s solve an example;
Find the height of the casting from its top when the rated static head is 34, the height of the sprue from its top to the point of metal entry into the mould cavity is 28 and the height of the casting is 14.

This implies that;

Hs = Rated Static Head = 34
H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity = 28
C = Height of the Casting = 14

p = – âˆš(Hs – H) x 2c
p = – âˆš(34 – 28) x 2(14)
That is, p = – âˆš6 x 28
p = – âˆš168
p = – 12.96

Therefore, theÂ height of the casting system from its topÂ isÂ – 12.96.

#### Calculating the Height of the Casting when the Rated Static Head, the Height of the Sprue from its Top to the Point of Metal Entry into Mould Cavity and the Height of the casting system from its top are Given

c = – p2 / (Hs – H) x 2

Where;

C = Height of the Casting
H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity
P = Height of the Casting from its Top

Let’s solve an example;
Find the height of the casting when the rated static head is 24, the height of the sprue from its top to the point of metal entry into the mould cavity is 12 and the height of the casting system from its top is 10.

This implies that;

Hs = Rated Static Head = 24
H = Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity = 12
P = Height of the Casting from its Top = 10

c = – p2 / (Hs – H) x 2
c = – 102 / (24 – 12) x 2
So, c = – 100 / 12 x 2
c = – 100 / 24
c = – 4.16

Therefore, theÂ height of the castingÂ isÂ – 4.16.

### How to Calculate Rated Static Head in the Design of Gating System Using Nickzom Calculator

Nickzom Calculator â€“Â The Calculator Encyclopedia is capable of calculating the rated static head.

To get the answer and workings of the rated static head using the Nickzom Calculator â€“ The Calculator Encyclopedia.Â First, you need to obtain the app.

You can get this app via any of these means:

To get access to theÂ professionalÂ version via web, you need toÂ registerÂ andÂ subscribeÂ forÂ NGN 1,500Â perÂ annumÂ to have utter access to all functionalities.
You can also try theÂ demoÂ version viaÂ https://www.nickzom.org/calculator

Apple (Paid)Â â€“Â https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to theÂ Calculator Map,Â then click on Materials & MetallurgicalÂ underÂ Engineering.

Now, Click on Foundry TechnologyÂ underÂ Material & Metallurgical

Now, Click onÂ Design of Gating SystemÂ underÂ Foundry Technology

Then, Click on Rated Static HeadÂ underÂ Design of Gating System

The screenshot below displays the page or activity to enter your values, to get the answer for the rated static head according to the respective parameters which are the Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity (H), Height of the Casting System from its top (P) and Height of the Casting (C).

Now, enter the values appropriately and accordingly for the parameters as required by the Height of the Sprue from its Top to the Point of Metal Entry into the Mould Cavity (H) is 9, Height of the Casting System from its top (P)Â isÂ 5 and Height of the Casting (C) is 11.

Finally, Click on Calculate

As you can see from the screenshot above,Â Nickzom Calculatorâ€“ The Calculator Encyclopedia solves for the rated static head and presents the formula, workings and steps too.