SIST EN 12845-3:2024

SLOVENSKI STANDARD
01-julij-2024
Vgrajene naprave za gašenje - Avtomatski sprinklerski sistemi - 3. del: Navodila za
zaščito pred potresi
Fixed firefighting systems - Automatic sprinkler systems - Part 3: Guidance for
earthquake bracing
Ortsfeste Brandbekämpfungsanlagen - Automatische Sprinkleranlagen - Leitfaden für
Erdbebensicherungen
Installations fixes de lutte contre l'incendie - Systèmes d'extinction automatiques du type
sprinkleur - Partie 3: Recommandation pour le contreventement sismique
Ta slovenski standard je istoveten z: EN 12845-3:2024
ICS:
13.220.10 Gašenje požara Fire-fighting
91.120.25 Zaščita pred potresi in Seismic and vibration
vibracijami protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12845-3
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2024
EUROPÄISCHE NORM
ICS 13.220.20 Supersedes CEN/TS 17551:2021
English Version
Fixed firefighting systems - Automatic sprinkler systems -
Part 3: Guidance for earthquake bracing
Installations fixes de lutte contre l'incendie - Systèmes Ortsfeste Brandbekämpfungsanlagen - Automatische
d'extinction automatiques du type sprinkleur - Sprinkleranlagen - Teil 3: Leitfaden für
Partie 3 : Recommandation pour le contreventement Erdbebensicherungen
parasismique
This European Standard was approved by CEN on 8 April 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12845-3:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Design principles . 7
5 Sway bracing and sprinkler pipe support . 7
5.1 General. 7
5.2 Sway brace design. 8
5.2.1 Steps in designing sway brace . 8
5.2.2 Step 1, define sway bracing locations . 9
5.2.3 Step 2, calculate seismic design load for each sway bracing location . 13
5.2.4 Step 3, select the proper sway bracing shape, size and maximum length . 22
5.2.5 Step 4, select the proper method to attach the sway bracing to the structure and to the
piping . 25
6 Flexibility . 32
6.1 General. 32
6.2 Flexible couplings . 32
6.2.1 General. 32
6.2.2 Risers and standpipes . 32
6.2.3 Horizontal main distribution pipes and distribution pipes . 33
6.2.4 Drops . 33
6.3 Seismic separation assemblies . 34
7 Clearance . 37
7.1 Clearance around piping through walls or floors . 37
7.2 Clearance at sprinklers . 37
8 Other provisions. 37
8.1 Bracing of suspended ceilings . 37
8.2 Water supply . 37
8.3 Storage racks with in-rack sprinklers . 37
Bibliography . 38

European foreword
This document (EN 12845-3:2024) has been prepared by Technical Committee CEN/TC 191 “Fixed
firefighting systems”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2024, and conflicting national standards shall
be withdrawn at the latest by November 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TS 17551:2021.
In comparison with the previous edition, CEN/TS 17551:2021, the following technical modifications have
been made:
• scope of the document has been adjusted;
• ambiguities in the body text have been redrafted;
• figures have been updated.
This standard is included in a series of European standards:
CEN/TS 14816, Fixed firefighting systems — Water spray systems — Design, installation and maintenance;
EN 671 (all parts), Fixed firefighting systems — Hose systems;
EN 12094 (all parts), Fixed firefighting systems — Components for gas extinguishing systems;
EN 12101 (all parts), Smoke and heat control systems;
EN 12259 (all parts), Fixed firefighting systems — Components for automatic sprinkler and water spray
systems;
EN 12416 (all parts), Fixed firefighting systems — Powder systems;
EN 12845-1, Fixed firefighting systems — Automatic sprinkler systems — Part 1: Design, installation and
maintenance;
EN 12845-2, Fixed firefighting systems — Automatic sprinkler systems — Part 2: Design and installation of
ESFR and CMSA sprinkler systems;
EN 13565 (all parts), Fixed firefighting systems — Foam systems;
EN 14972 (all parts), Fixed firefighting systems — Water mist systems;
EN 17451, Fixed firefighting systems — Automatic sprinkler systems — Design, assembly, installation and
commissioning of pump sets.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document specifies requirements for earthquake protection of automatic sprinkler systems (see the
EN 12845 series of standards) and can be applicable to other water based fixed manual or automatic fire
fighting systems, according to local requirements. Requirements made herein are intended to greatly
improve the likelihood that the fire protection systems will remain in working condition during and after
an earthquake and minimize or prevent any potential water damage from fixed firefighting systems
leakage due to an earthquake.
This document does not cover all legislative requirements. In certain countries, specific national
regulations apply and take precedence over this document. Users of this document are advised to inform
themselves of the applicability or non-applicability for this document by their national responsible
authorities.
1 Scope
This document specifies requirements for earthquake protection of automatic sprinkler systems in
accordance with EN 12845:2015+A1:2019.
This document applies only to locations in earthquake zones in accordance with EN 1998-1:2004, 3.2.1
and the Nationally Determined Parameters.
NOTE The requirements in this document are based on the principle that certain peak ground acceleration
values are considered as an earthquake which require special means. Attention is drawn to EN 1998-1:2004 , where
a peak ground acceleration above 0,08 g (0,78 m/s ) is considered an earthquake risk. Additional characteristics,
NDP and/or NCI can exist in some countries as well as national annexes.
The principles defined in this document can be applicable to other water based fixed manual or automatic
fire fighting systems, according to local requirements.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1992-4, Eurocode 2 — Design of concrete structures — Part 4: Design of fastenings for use in concrete
EN 1998-1:2004 , Eurocode 8: Design of structures for earthquake resistance — Part 1: General rules,
seismic actions and rules for buildings
EN 12845, Fixed firefighting systems — Automatic sprinkler systems — Design, installation and
maintenance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1998-1:2004 , EN 12845 and
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
zone of influence
portion of the piping system reinforced by a single sway brace which is calculated on both risers and
horizontal pipes
Note 1 to entry: Depending if related to a lateral or a longitudinal brace, it can include main distribution or
distribution pipes and range pipes or main distribution or distribution pipes only (see 5.2.3.4, 5.2.3.5, 5.2.3.6).
3.2
seismic separation assembly
equipment of fittings, pipe, flexible pipe, and/or couplings that permits movement in all directions to
accommodate seismic differential movement across building seismic separation joints

As impacted by EN 1998-1:2004/AC:2009 and EN 1998-1:2004/A1:2013.
3.3
tension only bracing
equipment with slenderness ratio length to least radius of gyration larger than 200
3.4
fastener
attachment elements to the structure
3.5
sway brace
group of elements intended to prevent differential movements between pipes and structural elements
4 Design principles
Requirements given in this document fall into the following seven principles:
— brace sprinkler piping and other sprinkler related equipment (see 8.2) to minimize uncontrolled
differential movement between these installations and structures they are attached to; and
— provide flexibility on piping systems and on equipment where differential movement between
portions of those piping systems or equipment is expected; and
— provide clearance between sprinkler piping and structural members, walls, floors or other objects so
that potential damage from impact is minimized; and
— provide anchorage or restraint to minimize potential sliding and/or overturning of equipment such
as the booster pump, jockey pump, tanks, controller, battery package and diesel tank; and
— use types of pipe hangers in accordance with EN 12845 and sway bracing as required in this
document to minimize the potential for pull-out, properly locate them and attach them to structural
members only; and
— use types of pipe joining methods in accordance with this document to minimize potential pipe
breaks; and
— provide fire protection system plans and calculations with proper verification of design and proper
verification that the completed installation is in accordance with this document and installed in
accordance with EN 12845.
5 Sway bracing and sprinkler pipe support
5.1 General
The requirements given in this document are additional to the requirements for pipe support given in
EN 12845. Sway bracing of steel pipes for sprinkler systems minimize differential movements between
the piping system and the structure to which it is attached.
Actual design of sway bracing is based on horizontal seismic load. Acceptable sway bracing type,
orientation and attachment methods (to both the sprinkler pipe and the structure) shall simultaneously
provide adequate resistance to both the horizontal seismic load and the net vertical uplift force
component resulting from the horizontal seismic load less any effective offset to that vertical force
component due to sprinkler piping dead weight.
For sprinkler piping within a building, there are two types sway bracing designs two-way and four-way.
Figure 1 shows two-way and four-way braces. They may be either longitudinal or lateral. Longitudinal
and lateral braces shall resist differential movement parallel and perpendicular, respectively, to the axis
of the pipe, regardless the slope of the pipe, and may be used on trunk mains, distribution pipes,
regardless of size, and system range pipes that are DN65 and larger in diameter (see 5.2.2.5.2 and
5.2.2.5.3).
Key
1 two-way brace longitudinal 3 four-way-brace
2 two-way brace lateral
Figure 1 — Sway bracing identification
For sway braces to protect the fire sprinkler pipelines against damage from earthquakes, their
components (with the exception of concrete anchors or dowels, see 5.2.5.3) shall be designed for a
seismic load capacity using a minimum 1,5 safety factor over the design earthquake load.
5.2 Sway brace design
5.2.1 Steps in designing sway brace
There are four general steps to properly design sway bracing.
— Step 1: Define sway bracing locations with respect to the sprinkler piping and to the structural
members to which the bracing will be attached.
— Step 2: Calculate the horizontal seismic design load for each sway bracing location.
— Step 3: Select the proper sway bracing shape, angle of attachment, size and maximum length based
on the horizontal design load requirement.
— Step 4: Select the proper method to attach the sway bracing to the structure and to the piping.
5.2.2 Step 1, define sway bracing locations
5.2.2.1 Risers
A four-way sway brace shall be provided for all sprinkler risers within 0,6 m of the top of the riser (see
5.2.2.5.4 for exceptions). Brace shall be attached to a structural element for risers located either on the
outside or on the inside of the building. Any riser shall be braced individually. See Figure 2 and 3.

Key
1 structural element (given as example- roof could be sloped or flat) 5 0,6 m maximum
2 roof 6 elbow, flexible coupling
3 4-way brace 7 flexible coupling
4 cladding (not structural element)
Figure 2 — Examples of locations of 4-ways sway bracing and flexible couplings for riser
Four-way sway bracing shall be provided at an interval (vertical distance) not to exceed 12 m. Where
flexible couplings are used provide flexibility as per Clause 4 and see 6.2.2, four-way sway bracing shall
be provided within 0,6 m of every other flexible coupling, with no more than two flexible couplings
between sway brace locations. See Figure 3. On risers with multiple horizontal outlets a four-way brace
shall be provided at each outlet.
Key
1 4-way sway bracing at top of riser and flexible 5 lateral sway bracing
couplings within 0,6 m (as shown in Figure 2)
2 flexible couplings 6 manifold support (0,9 m maximum)
3 0,6 m maximum
4 rigid coupling
Figure 3 — Location of 4-ways sway bracing and flexible couplings for riser with manifold
A two-way lateral sway brace shall be provided within 0,6 m of the end of any horizontal manifold piping
longer than 1,8 m, or when there is one or more flexible coupling(s) on either the horizontal manifold
piping or on the riser stub between the floor and the connection to the horizontal manifold piping.
Four-way sway bracing shall be provided at both the top and bottom of the vertical pipe 1,8 m long or
more. Each brace shall be located within 0,6 m of the respective piping turn. In addition, flexible couplings
shall be provided at the top and bottom.
For vertical pipes less than 1,8 m without bracing, flexible couplings shall not be present within the
vertical pipes (including the piping turns). If flexible couplings are provided at one or both turns for
vertical pipes less than 1,8 m, then four-way bracing shall be provided within 0,6 m of each turn equipped
with flexible coupling(s).
5.2.2.2 Horizontal changes of direction
Distribution pipe or main distribution piping that has a pipe length of 1,8 m or more adjacent to the
change in direction shall be provided with both lateral and longitudinal sway bracing within 0,6 m the
change of direction.
Straight pipe located after the last change in direction shall be provided with sway bracing as given in
5.2.2.3, 5.2.2.4 and 5.2.2.5. When the pipe connection at the change in direction is made using a flexible
coupling, then additional sway bracing as given in 5.2.2.5 shall be used, regardless of the length of the
pipe adjacent to the change in direction.
All requirements in this clause also apply to range pipes of DN65 and higher.
5.2.2.3 Ends of main distribution pipes and distribution pipes
Lateral bracing shall be provided within 1,8 m of the end and provided longitudinal bracing within 12 m
of the end. When structural member locations for lateral sway bracing attachment are such that this 1,8 m
distance cannot be met, the distribution pipe or main distribution pipe shall be extended to allow proper
location of the lateral sway bracing. Seismic separation assemblies shall be treated as the end of piping
on both sides of the assembly (see Figure 17, key 1).
5.2.2.4 Unnecessary flexible couplings
When more flexible couplings are installed on main distribution pipes and distribution pipes, regardless
of size, or on range pipes or portions of range pipes that are DN65 and larger and greater than 6 m in
length, additional lateral sway bracing shall be installed as follows:
— within 0,6 m of every other flexible coupling on straight pipes; and
— within 0,6 m of every flexible coupling installed at changes in horizontal pipe direction.
5.2.2.5 Horizontal and sloped straight pipes
5.2.2.5.1 General
Additionally to the requirements in 5.2.2.1 to 5.2.2.5, sway bracing shall be provided at a maximum
spacing of 12 m for lateral sway bracing and 24 m for longitudinal sway bracing.
5.2.2.5.2 Lateral sway bracing
Lateral sway bracing shall be provided on all main distribution pipes and distribution pipes regardless of
size, and on all range pipes and portions of range pipes that are DN 65 and larger and greater than 1,8 m
in length. Space bracing at a maximum of 12 m, recognizing that for main distribution pipes and
distribution pipes, there shall be lateral bracing within 1,8 m of the end of the main(s), as given in 5.2.2.4.
Only for range pipes less than DN 100 in diameter, lateral sway bracing can be omitted on pipes supported
by rods that meet the following criteria:
— all rods shall not be used to support other services;
— all rods shall have a length of no more than 150 mm from the supporting member attachment to the
top of the range pipe;
— there shall be no more than 13 mm of space between the top of the range pipes and the bottom of the
support rod.
A four-way brace on a vertical pipe (e.g. at the top of a riser) can be counted as the initial lateral brace for
an attached horizontal pipe of the same or smaller diameter when the brace is located within 0,6 m of the
horizontal pipe.
The loads from range pipes or portions of range pipes DN 65 or larger and less than 1,8 m in length shall
be distributed to the longitudinal sway bracing on the distribution pipe as given in 5.2.3.
U-hangers, including wraparound types, shall not be used as lateral sway bracing for main distribution
pipes and distribution pipes. Wraparound U-hangers can be used as lateral sway bracing for range pipes
that require sway bracing if they meet the following criteria:
— have both legs bent out at least 30° from the vertical as given in the manufacturer’s documentation;
— have the diameter, length and load capacity for the seismic loads involved as given in the
manufacturer’s documentation;
— are attached to the building structure as given in 5.2.5; and
— there is no more than 13 mm of space between the top of the range pipes and the wraparound portion
of the U-hanger.
If a longitudinal brace is within 0,6 m of a pipe connection to another pipe which is perpendicular and of
the same or lesser pipe size, then the longitudinal brace can be used to also act as a lateral brace for this
perpendicular pipe.
Bracing to smaller pipes shall not be used to brace larger pipes.
Usage of braces on range pipes and riser nipples to brace distribution pipes shall not be used.
5.2.2.5.3 Longitudinal sway bracing
Longitudinal sway bracing shall be provided on all main distribution pipes and distribution pipes
regardless of size and on all range pipes and portions of range pipes that are DN 65 and larger, and greater
than 12 m in length. Space bracing at a maximum of 24 m, recognizing that for main distribution pipes
and distribution pipes, there shall be longitudinal bracing within 12 m of the end of the main(s), as given
in 5.2.2.4.
A four-way brace on a vertical pipe (e.g. at the top of a riser) can be counted as the initial longitudinal
brace for an attached horizontal pipe of the same or smaller diameter when the brace is located within
0,6 m of the horizontal pipe.
If a lateral brace is within 0,6 m of a pipe connection to another pipe which is perpendicular and of the
same or lesser pipe size, then the lateral brace can be used to also act as a longitudinal brace for this
perpendicular pipe.
Bracing to smaller pipes shall not be used to brace larger pipes.
Usage of braces on range pipes and riser nipples to brace distribution pipes shall not be used.
5.2.2.5.4 Restraints
Range pipes DN 50 and smaller require restraint from excessive lateral movement and possible damage.
This can be done using sway braces, restraints or other alternative solutions to resist the movement.
Restraints do not require a load design or a minimum size.
For tree or looped systems:
— at the end of a range pipe, a restraint within 0,9 m for DN 25 pipe or 1,2 m for pipe DN 32 thru DN 50
shall be installed;
— risers up to DN 50 and no longer than 1,8 m supplying a single sprinkler shall not need any restraint
or sway bracing;
— additional restraints shall be installed along the range pipe length at a maximum spacing of 24 m.
For gridded systems restraints shall be installed along the range pipe length at a maximum spacing of
24 m.
5.2.3 Step 2, calculate seismic design load for each sway bracing location
5.2.3.1 General
The design load shall be calculated using one of the two alternative methods:
— Eurocode method given in 5.2.3.2, Formula (1); or
— the simplified method according to 5.2.3.3.
Both methods lead to the calculation of F , which is the horizontal force caused by the seismic actions on
a
the pipes.
5.2.3.2 Eurocode method in accordance with EN 1998-1:2004
This method refers to the calculation procedure proposed in EN 1998-1:2004 ) applies to non-structural
elements as sprinkler pipes are. The following formula has been adapted to consider the specificity of the
sprinkler systems piping.
The effects of the seismic action shall be determined by calculating the horizontal force F which is
a
defined as follows:
S ××W g
( )
a aa
F = (1)
a
q
a
where
F horizontal seismic force, acting at the centre of mass of the water-filled piping in the
a
most unfavourable direction;
W weight of the water-filled piping inside the chosen zone of influence;
a
S seismic coefficient;
a
g importance factor of the element;
a
q behaviour factor of the element.
a
NOTE 1 Figures 4 to 8 provide examples of typical zone of influence and appropriate bracings.
The importance factor of the elemen
...