doi: 10.21495/em2024-198
30 h In e na ional Con e ence
ENGINEERING MECHANICS 2024
Milo y, Czech Republic, May 14 – 16, 2024
ASPECTS OF ADAPTATION OF FLANGE JOINTS
FOR MODERN LOW-CARBON ENERGETICS
Michálko á A.*, Jegla Z.**, K išpín J.***, G oss A.†, Reppich M.††
Abs ac : This s udy in es iga es he possible need o lange join design adap a ion when dealing wi h
hyd ogen. The s udy ocuses on he compa ison o lange join design wi h wo di e en leakage a es
ep esen ing he need o highe igh ness due o he leak-p one na u e o hyd ogen molecules. The model
calcula ion ollowing he Eu opean s anda d EN 1591-1 based on an indus ial lange join in a na u al gas
pipeline ou lines he impac o changing igh ness class on load a ios o bol s, gaske and langes. While
he ope a ion emains sa e in he speci ic case s udied, he indings unde sco e he need o ca e ul
conside a ion in lange join design when swi ching o na u al gas hyd ogen blends o pu e hyd ogen, ensu ing
bo h he sa e y and eliabili y o he p ocesses in mode n low-ca bon ene ge ics.
Keywo ds: Flange join igh ness, hyd ogen, gaske sui able o hyd ogen.
1. In oduc ion
Bol ed lange join s a e widely used ac oss a ious indus ies, pa icula ly in si ua ions whe e join
disman ling is necessa y o example due o pe iodical main enance. The eliabili y o lange join s is i al
o ensu e he sa e y and eliabili y o he en i e p ocess o sys em. One o he consequences o an imp ope
design and subsequen ailed lange join is he leakage o ope a ing media posing a signi ican impac
on he en i onmen and also pe sonnel sa e y. The e o e, high demands a e placed on he join s no only
o wi hs and p essu e and o he mechanical and he mal loads sa ely bu also o main ain su icien igh ness
o a oid po en ially dange ous leaks. The design and e alua ion o bol ed lange join s acco ding
o Eu opean s anda d EN 1591-1 (The Czech O ice o S anda ds, Me ology and Tes ing [OSMT], 2015)
enable he leakage a e es ima ion based on gaske es da a acco ding o s anda d EN 13555 (Czech
S anda diza ion Agency [CSA], 2021).
2. Discussion o enginee ing aspec s o hyd ogen u iliza ion
Wi h he inc easing emphasis on sus ainable ene gy sou ces and mi iga ing ca bon emissions o achie e
he 2050 ca bon neu ali y commi men , hyd ogen is widely esea ched as a clean sou ce o ene gy.
Hyd ogen can be used as uel o an ene gy ca ie and s o age. Howe e , he u iliza ion o hyd ogen p esen s
unique challenges including hyd ogen damage mechanisms (hyd ogen-induced c acking, hyd ogen
emb i lemen , hyd ogen blis e ing), changes in equipmen ope a ing condi ions and also he need o highe
equipmen igh ness as hyd ogen molecules a e ex emely small and he e o e suscep ible o highe a es
o leaking. P ope design o lange join wi h ega d o i s igh ness becomes impe a i e as hyd ogen
* Ing. Anežka Michálko á: Ins i u e o P ocess Enginee ing, Facul y o Mechanical Enginee ing, B no Uni e si y o
Technology (BUT), Technická 2896/2; 616 69, B no; CZ, [email p o ec ed]
** Assoc. P o . Ing. Zdeněk Jegla, PhD.: Ins i u e o P ocess Enginee ing, Facul y o Mechanical Enginee ing, B no Uni e si y
o Technology (BUT), Technická 2896/2; 616 69, B no; CZ, [email p o ec ed]
*** Ing. Jan K išpín: ORGREZ, a.s.; Hudco a 76; 612 00, B no; CZ, [email p o ec ed]
† Ing. e Ing. A noš G oss: Veolia Ene gie ČR, a.s.; 28. října 3337/7; 702 00, Os a a; CZ, a nos .g os[email p o ec ed]
†† P o . D .-Ing. Ma cus Reppich: Facul y o Mechanical and P ocess Enginee ing, Augsbu g Uni e si y o Applied Sciences;
An de Hochschule 1; 86161, Augsbu g; DE, ma cus. eppic[email p o ec ed]
198
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is odou less, colou less, as eless and lammable and po en ially explosi e. Hyd ogen leaks a e especially
dange ous indoo s, in a poo ly en ila ed spaces, whe e he gas canno be quickly dilu ed in o
a non- lammable concen a ion.
This s udy ocuses on he compa ison o wo e sions o he same lange join – one designed wi h a lowe
Tigh ness Class and he o he one designed wi h a s ic e Tigh ness Class ep esen ing he need o highe
igh ness when dealing wi h hyd ogen. The ypical design o a bol ed lange join wi h wo weld-neck
langes wi h aised ace and la gaske is shown in Fig. 1. This opic was inspi ed by a high numbe
o scien i ic a icles explo ing he possibili y o using exis ing na u al gas pipeline ne wo k o anspo
na u al gas hyd ogen blends o pu e hyd ogen. Howe e , mos o hese a icles a e gene al and lack speci ic
de ails such as lange join s. The gene al consensus is ha blends up o abou 20 ol. % o hyd ogen should
no ha e a signi ican impac on he pipeline (E dene e al., 2023). This appea s o be con i med
by a esea ch p ojec in Ge many, whe e 20 % hyd ogen blend was anspo ed in he na u al gas g id
o egula households wi h no signi ican echnical issues o leaks (Dö e al., 2023).
Fig. 1: Ske ch o a ypical bol ed lange join wi h a la gaske .
2.1. Design o lange join s wi h leakage a e es ima e
The calcula ion me hod ou lined in Eu opean s anda d EN 1591-1 (OSMT, 2015) sa is ies bo h leak
igh ness and s eng h c i e ia o lange join design. I a selec ed leakage a e is o be achie ed, he gaske
p ope ies ha e o be assumed om es esul s pe o med acco ding o Eu opean s anda d EN 13555
(CSA, 2021) wi h helium as he ope a ing medium. The calcula ion in ol es an elas ic analysis o he load
and de o ma ion esponse be ween bol s, langes and gaske , conside ing po en ial plas ici y o gaske
ma e ial du ing assembly. This calcula ion me hod conside s bo h in e nal and ex e nal loads and loading
o he lange join mus be axisymme ic as mus be he geome y. O he assump ions on which
he mechanical model is based in his calcula ion me hod include: only ci cum e en ial s ess and s ain
in he lange ing is conside ed and gaske – lange con ac is an annula a ea. This me hod does no ake bol
bending in o accoun .
Annex I o EN 1591-1 (OSMT, 2015) ou lines he p ocedu e o leakage a e con e sion om e e ence
( es ) o ac ual ope a ing condi ions. Howe e , his p ocedu e canno be used o de e mine he ac ual
on-si e leakage a e due o he incomple e unde s anding o leakage mechanisms. The e o e, his annex only
p o ides a summa y o he gene al co ela ions and should be conside ed indica i e only i used. The e o e,
his calcula ion would no be pe o med.
2.2. Gaske s sui able o hyd ogen u iliza ion
The ma e ial o he selec ed gaske mus be chemically esis an o hyd ogen. Gaske manu ac u e s usually
conduc a se ies o addi ional es s o p o e chemical esis ance. Fo long- e m leak igh ness in a hyd ogen
en i onmen , gaske ma e ials based on elas ome s o PTFE a e no sui able due o elas ome emb i lemen
o e ime and he ime-dependen c eep o PTFE as epo ed by SGL Ca bon GmbH (2022). These gaske
ma e ials show signi ican inc ease in leakage o e ime. Howe e , gaske s om lexible g aphi e do no
demons a e his kind o beha io and leakage a e emains cons an o e ime as shown in Fig. 2.
Bol
Flange A
Flange B
Gaske
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3
Fig. 2: Leakage a e o e ime o di e en gaske ma e ials (SGL Ca bon GmbH, 2022).
3. Model calcula ion o he hyd ogen e ec on he design o lange join igh ness
The model calcula ion is based on an indus ial lange join used o inco po a e a low me e in o a pipeline
anspo ing na u al gas o combus ion in a u nace. The lange join consis s o wo simila DN100 PN16
weld-neck langes as gi en in EN 1092-1 (Czech S anda diza ion Agency [CSA], 2019) wi h ongue/g oo e
lange acings. The minimum equi ed gaske su ace p essu e a assembly 𝑄() and minimum equi ed
gaske su ace p essu e in subsequen se ice condi ions 𝑄 () o Sig a lex Uni e sal PRO gaske
o Tigh ness Classes L0.01 and L0.001 a e shown in Tab. 1, whe e 𝑄 is gaske su ace p essu e a assembly
p io o unloading.
𝐿
[
𝑚𝑔
/
(
𝑠
∙
𝑚
)
]
𝑄

(

)
[
𝑀𝑃𝑎
]
𝑄


(

)
[
𝑀𝑃𝑎
]
𝑄

=
20
𝑀𝑃𝑎
𝑄

=
30
𝑀𝑃𝑎
𝑄

=
40
𝑀𝑃𝑎
𝑄

=
60
𝑀𝑃𝑎
0.01 11 5 5 5 5
0.001 27 - 18 9 5
Tab. 1: Minimum equi ed gaske su ace p essu e o di e en igh ness classes, alid o PN16 (16 ba )
(Müns e Uni e si y o Applied Sciences, 2019).
Ma e ials used o langes and bol s a e P250GH and C45E, espec i ely. Assessmen o he sui abili y
o hese ma e ials o hyd ogen ope a ion was no he subjec o his wo k. The se ice condi ions a e gi en
in Tab. 2.
Assembly Hyd aulic es Ope a ing condi ions
P essu e [MPa] 0 2.288 1.6
Tempe a u e [°C] 20 20 50
Axial o ce [N] 0 0 0
Bending momen [N.m] 0 0 0
Radial o ce [N] 0 0 0
To sional momen [N.m] 0 0 0
Tab. 2: Se ice condi ions.
Bo h calcula ions we e based on he minimum equi ed p essu e limi s. The equi ed bol o ce is 80 𝑘𝑁
and 150 𝑘𝑁 espec i ely o he wo igh ness classes. The esul ing load a ios a e gi en in Tab. 3.
200
4
Assembly Hyd aulic es Ope a ing condi ions
Bol s L0.01 27.2 % 13.9 % 19.4 %
L0.001 51.1 % 27.9 % 41.0 %
Gaske L0.01 10.9 % 2.5 % 3.3 %
L0.001 20.5 % 9.0 % 10.1 %
Flange L0.01 20.1 % 14.3 % 18.6 %
L0.001 37.7 % 26.4 % 36.7 %
Tab. 3: Flange join load a ios.
The change in igh ness class esul ed in highe load a ios o bol s, gaske and lange. As none o he load
a ios exceed 100 %, he ope a ion o he lange join is s ill sa e a e he igh ness change. Howe e , his
model calcula ion highligh s he possibili y o a load a io exceeding 100 % due o he highe minimum
o ce equi ed o a highe igh ness class. In ha case, he eplacemen o he langes could be needed
o wi hs and highe mechanical load.
4. Conclusions
This s udy desc ibes he possible need o lange join design adap a ion in connec ion o mode n
low-ca bon ene ge ics, ocusing on hyd ogen and he challenges connec ed o swi ching o na u al gas
hyd ogen blends in he exis ing na u al gas pipeline ne wo k. The compa ison o wo lange join designs,
di e ing in leakage a es, se es as a p ac ical example o adap ing enginee ing solu ions o he speci ic
demands o hyd ogen applica ions such as he need o highe igh ness o p ocess equipmen . Wi h a lowe
allowable leakage a e, he load a ios o bol s, gaske and langes a e highe due o he highe equi ed
gaske su ace p essu e.
Acknowledgemen
This esea ch was conduc ed wi h he s a e suppo o he Technology Agency o he Czech Republic
as pa o he p ojec "Technical solu ions o low-emission ene gy" o he p og am "Na ional Cen e o
Ene gy II" (TN02000025) and was suppo ed by unds om GA BUT wi hin esea ch p ojec FSI-S-23-
8173 and by he EU p ojec S a egic Pa ne ship o En i onmen al echnologies and Ene gy P oduc ion,
unded as p ojec No. CZ.02.1.01/0.0/0.0/16_026/0008413 by Czech Republic Ope a ional P og amme
Resea ch, De elopmen and Educa ion.
Re e ences
Czech S anda diza ion Agency (2019) Flanges and hei join s – Ci cula langes o pipes, al es, i ings and
accesso ies, PN designa ed – Pa 1: S eel langes (ČSN EN 1092-1). P ague (in Czech).
Czech S anda diza ion Agency (2021) Flanges and hei join s – Gaske pa ame e s and es p ocedu es ele an o
he design ules o gaske ed ci cula lange connec ions (ČSN EN 13555). P ague.
Dö H., B andes A., K onenbe ge M., Janßen N., Geh mann S. (2023) Wasse s o in de Gasin as uk u :
DVGW/A acon-Pilo o haben mi bis zu 20 Vol.-% Wasse s o -Einspeisung in E dgas – H2-20. Deu sche
Ve ein des Gas- und Wasse aches e. V., Bonn (in Ge man).
E dene B.C., Se gi B., Gue a O. J., Chueca A. L., Pambou K., B ancucci C. and Hodge B. (2023) A e iew o
echnical and egula o y limi s o hyd ogen blending in na u al gas pipelines. In e na ional Jou nal o Hyd ogen
Ene gy, 48, 14, pp. 5595–5617.
Müns e Uni e si y o Applied Sciences (2019) Sig a lex Uni e sal P o V20010C2I-P (2 mm)
h ps://gaske da a.o g/en/SGL-Ca bon-GmbH/Sig a lex-Uni e sal-P o-V20010C2I-P/de ail/334/
SGL Ca bon GmbH (2022) Long- e m sa e sealing o hyd ogen wi h SIGRAFLEX ®
h ps://www.sglca bon.com/da a/pd /SGL-Technical-In o-SIGRAFLEX-Hyd ogen-EN.pd
The Czech O ice o S anda ds, Me ology and Tes ing (2015) Flanges and hei join s – Design ules o gaske ed
ci cula lange connec ions – Pa 1: Calcula ion (ČSN EN 1591-1). P ague (in Czech).
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