Calculation of sizing safety valves

Fill the form in the next three steps to complete your calculation sheet.

Check the right choices and download the PDF file of calculation of sizing safety valves.

STEP A
Calculation of minimum flow area Ac for sizing pressure relief valve,
according to EN 13136:2013 Standard
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STEP A.1
Selection of refrigerant Choose the refrigerant from the drop down menu
Fluid group, according to Art. 13 , Directive 2014/68/EU - This datum is a function of the selected refrigerant
Isoentropic exponent of the refrigerant , as measured at 25 °C and 1,013 bar - k - This datum is a function of the selected refrigerant
Function of the isoentropic exponent - C - This datum is a function of the selected refrigerant
Vapour density at refrigerant saturation pressure/dew point at 10 °C - ϱ10 (0 °C for R744) - This datum is a function of the selected refrigerant

STEP A.2
Selection of set pressure - Pset (NB: Pset ≤ PS of equipment to be protected) Choose the Pset from the drop down menu
Actual relieving pressure - Po - Calculated datum
Actual back pressure - Pb - Atmospheric pressure
Saturated temperature at Po - To - This datum is a function of the selected refrigerant and the selected Pset
Specific volume of vapour at Po - Vo - This datum is a function of the selected refrigerant and the selected Pset

STEP A.3
Select an option:

STEP A.4
Selection of Castel safety valve Choose the safety valve model from the drop down menu

NB: if you use a fluid Group 1, you can only choose from the 3061 and 3065 valves
Flow area - A - This datum is a function of the selected safety valve model
Certified coefficient of discharge - Kd - This datum is a function of the selected safety valve model
Calculation of flow rate - Qm - This datum is a function of the selected safety valve model

STEP A.5
Check of the safety valve selection - Calculated datum

STEP A.6
Calculation of minimum flow area - Ac (par. 7.2.5 of EN 13136:2013 + A1) - Calculated datum
Adjusted discharge capacity - Qmd' - Calculated datum
STEP B
Calculation of pressure loss ΔPin in upstream line, according to EN 13136:2013 Standard
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STEP B.1
Inside diameter of inlet tube - Din [mm] Enter datum
Length of inlet tube - Lin [mm] Enter datum
Inside area of inlet tube - Ain - Calculated datum
Connection of inlet tube (see Table 2 on instructions) Choose the connection from the drop down menu
Pressure loss coefficient for inlet connection - ξC - This datum is a function of the selected connection
Pressure loss coefficient for inlet length - ξL - Calculated datum
Shut-off valve Choose the shut-off valve model from the drop down menu
Inside diameter of valve - Dvalve - This datum is a function of the selected shut-off valve model
Kv factor of valve - This datum is a function of the selected shut-off valve model
Inside area of valve - Avalve - Calculated datum
Pressure loss coefficient for shut-off valve - ξV - Calculated datum
Total pressure loss coefficient - ξT - Calculated datum

STEP B.2
Calculation of pressure loss - ΔPin (par. 7.4.3 of EN 13136:2013) - Calculated datum
Maximum pressure loss in upstream line 0,03 x Po (par 7.4.1 of EN 13136:2013) - Calculated datum
Check of the pressure loss - Calculated datum




STEP C
Calculation of pressure loss ΔPout in downstream line, according to EN 13136:2013 Standard
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STEP C.1
Inside diameter of outlet tube - Dout [mm] Enter datum
Length of outlet tube - Lout [mm] Enter datum
Inside area of outlet tube - Aout - Calculated datum
First bend of outlet tube (see Table 2 on instructions) Choose the pipe bend from the drop down menu
Second bend of outlet tube (optional) Choose the pipe bend from the drop down menu
Third bend of outlet tube (optional) Choose the pipe bend from the drop down menu
Pressure loss coefficient for outlet bends - ξB - This datum is a function of the selected pipe bends
Pressure loss coefficient for oulet length - ξL - Calculated datum
Total pressure loss coefficient - ξT - Calculated datum

STEP C.2
Calculation of pressure loss - ΔPout (par. 7.4.4 of EN 13136:2013) - Calculated datum
Maximum pressure loss in downstream line 0,10 x Po (par 7.4.1 of EN 13136:2013) - Calculated datum
Check of the pressure loss - Calculated datum