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Power-User

Join Date: Jun 2008
Location: beverly hills
Posts: 115

### displacer level

12/01/2008 12:43 AM

Dear, all

how to calculate level displacer?

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Guru

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing. Kettle's on.
Posts: 19628
#1

### Re: displacer level

12/01/2008 3:30 AM

In what context?

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Power-User

Join Date: Nov 2008
Location: Johannesburg
Posts: 298
#2

### Re: displacer level

12/02/2008 5:26 AM

Hi there,

If you looking for the sizing of displacers then this might help:

The displacer diameter sets the weight change of the displacer per level increment. The torque tube is designed to twist a fixed amount for each increment of buoyancy change. Therefore, in selecting the displacer diameter, the torque tube characteristics, the density of the process fuid, and the level span must be considered.

You will need to look at the technical documents for the actual device to confirm the actual numerical constants to use

You can use the following formulas though:

Volume=(Torque tube force)/(Delta SG)*(wt of i cubic inch H2O)

Diameter=((4V)/(piL))^1/2

Force (buoyant) = (0.36)*(SG)*(V)*(Lw)/L

Where SG - Specific gravity

V - Displacer volume in cubic inches

Lw - Working length of displacer in inches

L - Total length of displacer in inches

You should bear in mind that the displacers and chambers come in a fix range of sizes - these formulas are to help you select the correct size.

Regards

Craig

Power-User

Join Date: Mar 2008
Location: Mumbai
Posts: 232
#3

### Re: displacer level

12/03/2008 12:53 AM

Hi,

A) First determine your level (HHLL-LLLL) EG 900 mm,

B) Decide your displacer length From the following to cover the entire measuring range in (A) + 20% additional lenth

1) 356

2) 813

3)1219

4) 1524

5) 1824

C) Select diplr length of 1219 mm

As mentioned in the previous post then determine your displr diameter

Note 1) Displacer length depends on the manufactuers std /EPC standard drawings

Regards

Jose