6 replies to this topic

[babakfarhadi]

Hi Dear,

 

I want start design for burst disc install on the CO2 cylinder valve.This rupture disc burst pressure must be 190 bar I found formula but difference between calculation and experimet is high.Can anyone help me?

 

Disc OD : 10 mm

Disc Thickness : 0.04 mm

Disc is circular flat plate

 

Best Regard,

Babak Farhadi

[fallah]

Babak,

 

Which method/equation/formula is used for your calculation? Which experiment you did refer to?

 

As you know the burst pressure of a disc is to be determined by the thickness and the strength of the disc material. Then, don't you think a disc with 0.04 mm thickness, with any material, cannot withstand agianst a pressure equal to 190 barg?

[babakfarhadi]

Fallah,

 

Thank you for reply.

1.I used Stainless Steel 301 with OD 10 mm and Thickness 0.04 in my experiment fix this plate between two plate of brass and then increase a pressure ,this pressure monitor with indicator connected to pressure transmitter.

pressure increase up to disc rupture when disc burst i can view a max point of pressure goes down.I test this plate and burst pressure is 220 bar

 

2.I found formula for this experiment in http://www.roymech.c...ics/Plates.html.Stainless steel 301 UTS is 758 MPa

in this formula pressure calculate 1.5 bar

 

Im confused about this.I try to take a picture on my experiment device and then upload.

 

 

 

Best Regard

Babak Farhadi

[fallah]

Babak,

 

1-The experiment you described isn't so clear. A simple sketch may clarify the matter if to be added to description...

 

2-The burst pressure you calculate by formula appears to be ressonable as per the situation.

 

Nevertheless, the disc characteristics should be calculated/specified by a reputable vendor...

[babakfarhadi]

Dear Fallah

Plz see my attached file.https://docs.google....dit?usp=sharing

 

1.First Booster make a 300 bar pressure

2.I fix plate between brass plug and holder

3.Open P1 slowly to increase pressure back of plate

4.Pressure increase until burst disc rupture and pressure vent to air from plug hole

5.Read Max point of preesure on the indicator

6.For this plate is 220 bar

 

 

Best Regard

Babak Farhadi

[fallah]

Babak,

 

As i well understood from your six steps operation and the sketch, what pressure indicator would show cannot necessarily be burst pressure of the disc because based on size/lenght of the line terminated to the holder (not specified), after opening of the P1 it might the pressure to be built up at upstream of the disc due to its small size even if the disc would be burst just sensing a few bars pressure and is relieving the air...

[babakfarhadi]

Dear Fallah,

 

1.Distance between holder and p1 and other components are min.

2.Exactly,Burst pressure of flat plate depend on Thickness,Material,Hole Diameter of plug,Pressure,Temprature I want know equation between this value.

In the google you can find about "Rupture disc stress" or "Circular flat plate stress" But I want a practical formula?

 

Best Regard,

Babak Farhadi