Chapter 1: Static connections - cfservice.rocfservice.ro/pdf/CF_R_advisors.pdf · Chapter 1: Static connections ... Design rules for gasketed circular flange connections ... circular

Calculation methods for flange connections according to EN1591

Chapter 1: Static connections

®

®

®

Repair Advisors a division®

®

®

®

®

®

2 EN1591 Method Repair Advisors a division®

®

®

®

®

®

• Fluid pressure

• Mechanical resistance of the material of flanges, bolts and gaskets

• Bolt load stress

• Possible dispersion due to the flange assembly process

• Change of gasket stress due to deformation of the components

• Influence of piping tensions

• Effect of axial forces and external bending moments

• Effects of temperature difference between bolts and the flange ring

EN 1591 Parameters

Regulation EN1591: “Flanges and their joints – Design rules for gasketed circular flange connections (07/01/2003)” is the European reference law on the specific topic.

It is divided into two sections:

• EN 1591-1: Calculation method

• EN 1591-2: Gasket parameters

Preliminary notes

EN1591 sets leakage rates and mechanical resistance criteria for flanged connections.The behavior of the complete flanges-gasket-bolt system is considered both in assembly and working conditions.The calculation is based on the elastic analysis of the load/deformation relationships among every part of the flanged junction, corrected by the possible plastic behavior of the gasket.

Regulation EN1591:circular flange connections (07/01/2003)” is the European reference law on the

Preliminary notes

EN1591 Method 3 Repair Advisors a division®

®

®

®

®

®

Calculation methods for gasketed circular flange connections

Taylor – Forge Method EN1591–1 Method

CALCULATION METHODS

The admissibility of the assembly for the calculation

conditions is determined

The assembly behavior during its lifetime is analyzed. The recommended tightening

is defined according to leakage rate

The assembly is statically determined, but the reactions

evolution can’t be known

The behavior of the complete flanges-bolts-gasket system is considered, and the reactions

evolution can be known

Procedure comparison


®

®

®

®

®

Taylor - Forge Method

The admissibility of the assembly is determined by the flange stress values (Pic. 1), by the bolt section (Pic. 2) and by the gasket pressure value (m;Y) (Pic. 3).The evolution of the reaction can’t be known.

The force applied by the bolting remains constant at all steps of service

The load imposed on the gasket is the required one to provide seating

P

Σ shell

Σ int. gasket

Slide 4 alto a sinistra

F

F

Slide 4 alto a destra

Resisting section Allowable stress

Slide 4 basso a destra

sR

Radial stress

Longitudinal hub stress

Tangential stress

Slide 4 basso a sinistra

P

Balance of forces

Balance of deformations

Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba

Slide 5 alto a sinistra Slide 5 alto a destra

Z

Z


Bilanciamento delle deformazioni

tra

Axial deformations at the gasket place

Axial deformations of the bolts


1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)

CEN Constants definition - Leak vs Sg Idealized GraphFor 3 Loading and unloading cycles

Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno

sH

sRsT

Radial stress


Tangential stress

Pagina 3 Fig.1

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3

Disegno 1 Disegno 2

Pagina 4 Fig.3

Øint flangia

Øext flangia

Øint g.ne

Øext g.ne

sp. g

.ne

Pic. 1

Pic. 2

Pic. 3


®

®

®

®

®



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno

EN1591 Method



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno



P

Σ shell

Σ int. gasket


F

F




sR

Radial stress


Tangential stress


P

Balance of forces


Axisymmetric model

Laws of rheology

BI

B

BII

SI

S

SII

Sa

Ba


Z

Z



tra




1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3


sH

sT

Ønocciolo

Ømedio

Øesterno

The bolts are treated in section

Torsion phenomenon at tightening is considered

The behavior of the assembly is determined by the leak-tightness values, based on the deformation of the flange during its lifetime (Pic. 1), of bolts (Pic. 2) and the deformations of the gasket in both tightening and operative conditions (Qmin (L), Qmax, QA, EG) (Pic. 3)

Deformation balance between

Pic. 1

Pic. 2

Pic. 3

sH

sRsT

Radial stress


Tangential stress

Pagina 3 Fig.1

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3

Disegno 1 Disegno 2

Pagina 4 Fig.3

Øint flangia

Øext flangia

Øint g.ne

Øext g.ne

sp. g

.ne

sH

sRsT

Radial stress


Tangential stress

Pagina 3 Fig.1

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1000 10000 100000

Gasket Stress (psi)

Gas

ket L

eak

(mba

r l/m

s)

Qmin (L0.000001)

Qmin (L0.00001)

Qmin (L0.0001)

Qmin (L0.001)

Qmin (L0.01)

Qmin (L0.1)

QSmin (L0.000001)

QSmin (L0.01)


Sg1 Sg2 Sg3

Disegno 1 Disegno 2

Pagina 4 Fig.3

Øint flangia

Øext flangia

Øint g.ne

Øext g.ne

sp. g

.ne


®

®

®

®

®

Due to the large number of parameters to consider, the mathematical calculation procedure is extremely complicated and difficult.

Thanks to a 20-year experience in the field, to a constant follow-up on regulations, and to the cooperation with the major companies and agencies of the industry,

®

®

®

has developed a software aimed at analyzing at once all the necessary parameters according to EN1591.

EN1591 MethodCalculation example


®

®

®

®

®

Flanged connections control check

Excerpt of a calculation reportCalculation report

Condition Source Descriptionok Flange 1 (bF = 50,16 / eF = 18,20) ok = 2,76 >= 0,2ok Flange 1 (bF = 50,16 / eF = 18,20) = 2,76 <= 5,0ok Flange 1 cos(φS) = 0,87 >= 1/(1+0,01*ds/es) = 0,66ok Flange 2 (bF = 50,16 / eF = 18,20) = 2,76 >= 0,2ok Flange 2 (bF = 50,16 / eF = 18,20) = 2,76 <= 5,0ok Flange 2 cos(φS) = 0,87 >= 1/(1+0,01*ds/es) = 0,66ok assembly condition / Bolts FB0min = 267.026,00 >= FB0req = 35.221,80ok assembly condition / Bolts FB0req = 35.221,80 <= FB0max = 433.786,00ok assembly condition / Gasket ΦG = 0,05 <= 1

wrong assembly condition / Bolts ΦB = 2,25 <= 1.0ok assembly condition / Bolts FB0nom = 359.671,00 >= FB0req / (1 - ε)ok assembly condition / Joint FG0req = 35.221,80 >= FG0min = 35.221,80ok assembly condition / Flange 1 Ψmax = 0,09 < -1 or Ψmin = -0,09 > 1ok assembly condition / Flange 2 Ψmax = 0,09 < -1 or Ψmin = -0,09 > 1ok assembly condition / Flange 1 cM = 1,15 < 0ok assembly condition / Flange 2 cM = 1,15 < 0

wrong assembly condition / Flange 1 eF = 18,20 >= eFminA1 = 23,06wrong assembly condition / Flange 2 eF = 18,20 >= eFminA1 = 23,06

ok assembly condition / Flange 1 ΦF = 0,88 <= Φmax = 1,00

Name Value Unit DescriptioncS+’’ 0,79 -- (π/4)*(sqrt(1-0.75*(0.5*δQ+δR^2))+jS*(0.5*δR-0.75*δQ))cS-’’ 0,79 -- (π/4)*(sqrt(1-0.75*(0.5*δQ+δR^2))-jS*(0.5*δR-0.75*δQ))hG0’ 12,04 -- (d3e-dGe)/2hG0’’ 12,04 -- (d3e-dGe)/2

ΘFmaxE1’ 0,01 deg (ZF/EF)*{FG*hG+FQ*(hH-hP+hQ)+FR*(hH+hR)}ΘFmaxE1’’ 0,01 deg (ZF/EF)*{FG*hG+FQ*(hH-hP+hQ)+FR*(hH+hR)}ΘFminE1’ 0,01 deg (ZF/EF)*{FG*hG+FQ*(hH-hP+hQ)+FR*(hH+hR)}ΘFminE1’’ 0,01 deg (ZF/EF)*{FG*hG+FQ*(hH-hP+hQ)+FR*(hH+hR)}

FB0req 35,22 kN (53) = FG0req+FR0Mtnom 221,21 Nm (D.1) = kB*FB0nom/nB

MtBnom 113,23 Nm (D.8) = Mt.Bnom*(1+ε)MtBmax 136,56 Nm Mt.Bnom*(1+ε)eFminA1’ 23,06 mm pB*(((EGm*bGe)/(Ef*eG))*(pB/bF)*Sqrt(1-(ΦG0A1*bGt/bGe)^2)/10)^1/3eFminA1’’ 23,06 mm pB*(((EGm*bGe)/(Ef*eG))*(pB/bF)*Sqrt(1-(ΦG0A1*bGt/bGe)^2)/10)^1/3

ΦF’ 0,88 -- |FG*hG+FQ*(hH-hP)+FR*hH|/WF =ΦF’’ 0,88 -- |FG*hG+FQ*(hH-hP)+FR*hH|/WF =jM’ 1 -- sign{FG*hG+FQ*(hH-hP)+FR*hH}jM’’ 1 -- sign{FG*hG+FQ*(hH-hP)+FR*hH}kM’ 1 -- --kM’’ 1 -- --Ψopt’ 1 -- jM*(2*(eP/eF)-1)Ψopt’’ 1 -- jM*(2*(eP/eF)-1)Ψ0’ 0 -- ((fE*dE*eD*cos(φS))/(fF*2*bF*eF))*{(0.5*δQ+δR)+tan(φS)-δQ*2*(eP/dE)}Ψ0’’ 0 -- ((fE*dE*eD*cos(φS))/(fF*2*bF*eF))*{(0.5*δQ+δR)+tan(φS)-δQ*2*(eP/dE)}

Ψmax’ 0,09 -- Ψmax=((fE*dE*eD*cos(φS))/(fF*2*bF*eF)) *{(0.5*δQ+δR)+tan(S)-φQ*2*(eP/dE)+1*1*sqrt((eD*cM*cS*(1+1*1))/(dE*cos[3](δS))Ψmax’’ 0,09 -- Ψmax=((fE*dE*eD*cos(φS))/(fF*2*bF*eF)) *{(0.5*δQ+δR)+tan(S)-φQ*2*(eP/dE)+1*1*sqrt((eD*cM*cS*(1+1*1))/(dE*cos[3](δS))Ψmin’ -0,09 -- Ψ*min=((fE*dE*eD*cos(φS))/(fF*2*bF*eF))*{(0.5*δQ+δR)+tan(φS)-Q*2*(eP/dE)-1*1*sqrt((eD*cM*cS*(1-1*-1))/(dE*cos[3](δS)))Ψmin’’ -0,09 -- Ψ*min=((fE*dE*eD*cos(φS))/(fF*2*bF*eF))*{(0.5*δQ+δR)+tan(φS)-Q*2*(eP/dE)-1*1*sqrt((eD*cM*cS*(1-1*-1))/(dE*cos[3](δS)))ΨZ’ 0,09 -- --ΨZ’’ 0,09 -- --WF’ 5959,11 Nm (π/4)*{fF*2*bF*eF^2*(1+2*Ψopt*Ψz-Ψz^2)+fE*dE*eD^2*cM*jM*kM)WF’’ 5959,11 Nm (π/4)*{fF*2*bF*eF^2*(1+2*Ψopt*Ψz-Ψz^2)+fE*dE*eD^2*cM*jM*kM)


®

®

®

®

®

EN1591 Method

Resistance criteria

GASKET Limitation of the compression

BOLTS Limitation of the traction

FLANGES Limitation of the rotation

SEATiNG CRiTERiA

LEAK-TiGhTNESS CRiTERiA

BOLT STRENGTh CRiTERiA

GASKET STRENGTh CRiTERiA

FLANGE STRENGTh CRiTERiA

Lower tightening limit

Upper tightening limit

}

}


®

®

®

®

®

EN1591 Method

Tightening recommendation

Upper tightening limit

Tightening device scatter

Lower tightening limit }Bolt tightening

[ ]


®

®

®

®

®

EN1591 Method EN1591

THE ASSEMBLY BEHAvIoR DuRING ITS LIFETIME IS ANALYZED. THE RECoMMENDED TIGHTENING IS DEFINED ACCoRDING To LEAkAGE RATE

EN1591-1DESIGN RuLES FoR GASkETED CIRCuLAR

FLANGE CoNNECTIoNS

EvALuATIoN oF BoLTS’ INITIAL MINIMuM LoAD CAPACITY

EvALuATIoN oF THE INTERNAL FoRCES RESuLTING FRoM THE BoLT’S INITIAL

MINIMuM LoAD vALuE AND ANY oTHER LoAD CoNDITIoN (FuNCTIoN TEST)

MECHANICAL FEATuRESFLANGE

CHEMICAL AND PHYSICAL FEATuRES

GASKET

MECHANICAL FEATuRES

BOLTS

EN1591-2GASkET PARAMETERS

ANALYSIS oF THE FLANGE CouPLING

DEFINITIoN oF A LEAkAGE RATE

ANALYSIS oF THE FLANGED CoNNECTIoN’S uSE FEATuRES (FLuIDS, TEMPERATuRE, PRESSuRE)

DATA ouTPuT FRoM SoFTWARE

DATA PRoCESSING THRouGH CALCuLATIoN SoFTWARE

CHECk oF THE FLANGED CoNNECTIoN AND CouPLING BASED oN THE DETERMINED LEAkAGE RATE

®

®

®


®

®

®

®

®

The method stated so far evaluates the degree of fugitive emissions per pollutant based on the fixed leakage rate (L).The

®

®

® monitoring plan avails itself of the calculation outputs coming from EN1591.

This calculation method represents a valid alternative option, where possible, to other means of plant validation, such as:

• Specific tests

• EN1591 standard procedure

• usage of normalized flanged couplings

Advantages of the calculation method according to EN1591

®

®

®

via del vetro, 13/15 - 30020 Marcon (vE) ITALY Tel. +39 041.4568562 Fax +39 041.5952900 - [email protected] www.cfservice.it

®

®

®

Repair Advisors a division®

®

®

®

®

®

Documents

Chapter 1: Static connections - cfservice.rocfservice.ro/pdf/CF_R_advisors.pdf · Chapter 1: Static connections ... Design rules for gasketed circular flange connections ... circular