FprEN 88-2

SLOVENSKI STANDARD
oSIST prEN 88-2:2015
01-februar-2015
9DUQRVWQHLQQDG]RUQHQDSUDYH]DSOLQVNHJRULOQLNHLQSOLQVNHDSDUDWHGHO
7ODþQLUHJXODWRUML]DYVWRSQHWODNHQDGN3DGRYNOMXþQRN3DLQSULSDGDMRþH
YDUQRVWQHQDSUDYH
Safety and control devices for gas burners and gas burning appliances - Part 2: Pressure
regulators for inlet pressures above 50 kPa up to and including 500 kPa and associated
safety devices
Sicherheits- und Regeleinrichtungen für Gasbrenner und Gasgeräte - Teil 2: Druckregler
für Eingangsdrücke über 50 kPa bis einschließlich 500 kPa und dazugehörigen
Sicherheitseinrichtungen
Dispositifs de sécurité et de contrôle pour les brûleurs à gaz et appareils utilisant des
combustibles gazeux - Partie 2: Régulateurs de pression pour pressions amont
comprises entre 50 kPa et 500 kPa et dispositifs de sécurité associés
Ta slovenski standard je istoveten z: prEN 88-2 rev
ICS:
23.060.40 7ODþQLUHJXODWRUML Pressure regulators
oSIST prEN 88-2:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 88-2:2015
oSIST prEN 88-2:2015
EUROPEAN STANDARD
DRAFT
prEN 88-2 rev
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2014
ICS 23.060.40 Will supersede EN 88-2:2007
English Version
Safety and control devices for gas burners and gas burning
appliances - Part 2: Pressure regulators for inlet pressures
above 50 kPa up to and including 500 kPa and associated safety
devices
Dispositifs de sécurité et de contrôle pour les brûleurs à gaz Sicherheits- und Regeleinrichtungen für Gasbrenner und
et appareils utilisant des combustibles gazeux - Partie 2: Gasgeräte - Teil 2: Druckregler für Eingangsdrücke über 50
Régulateurs de pression pour pressions amont comprises kPa bis einschließlich 500 kPa und dazugehörigen
entre 50 kPa et 500 kPa et dispositifs de sécurité associés Sicherheitseinrichtungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 58.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 88-2 rev:2014 E
worldwide for CEN national Members.

oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Contents
Page
Foreword .4
1 Scope .7
2 Normative references .7
3 Terms and definitions .8
4 Classification . 12
5 Units of measurement and test conditions . 12
6 Design and construction . 13
7 Performance requirements . 16
8 Electrical requirements . 29
9 Electromagnetic compatibility (EMC) . 29
10 Marking, installation and operating instructions . 29
Annex A (informative) Void . 31
Annex B (informative) Leak-tightness test for gas controls – volumetric method . 32
Annex C (informative) Leak-tightness test for gas controls – pressure loss method . 33
Annex D (normative) Conversion of pressure loss into leakage rate . 34
Annex E (normative) Electrical/electronic component fault modes . 35
Annex F (normative) Additional requirements for safety accessories and pressure accessories
as defined in EU Directive 97/23/EC. 36
Annex G (normative) Materials for pressurized parts . 37
Annex H (normative) Additional materials for pressurized parts . 38
Annex I (normative) Requirements for controls used in DC supplied burners and appliances
burning gaseous or liquid fuels . 39
Annex J (normative) Method for the determination of a Safety integrity level (SIL) . 40
Annex K (normative) Method for the determination of a Performance Level (PL) . 41
Annex L (informative) Relationship between Safety Integrity Level (SIL) and Performance Level
(PL) . 42
Annex M (normative) Reset functions . 43
Annex N (informative) Guidance document on Environmental Aspects . 44
Annex O (normative) Seals of elastomer, cork and synthetic fibre mixtures. 45
Annex AA (informative) Typical pressure regulators and pressure regulator parts . 46
Annex BB (informative) Overview of requirements and test conditions (as given in Clause 7), and
examples of performance curves for pressure regulators . 49
Annex CC (normative) Creep relief device . 52
Annex DD (informative) Comparison between EN 334:2012-05 and EN 88-2:2013-04 . 54
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2009/142/EC relating to appliances burning gaseous fuels . 55
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Annex ZB (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC concerning pressure equipment . 57
Bibliography . 59

Figures
Figure 1 — Performance test apparatus . 19
Figure 2 — Graphical representation of 7.101.2.5.2 . 22
Figure 3 — Performance test apparatus for SSDs . 25
Figure 4 — Measurement of response time . 27
Figure AA.1 — Example of a direct acting regulator . 46
Figure AA.2 — Example of regulator using auxiliary energy . 47
Figure AA.3 — Example of a pilot controlled regulator . 47
Figure AA.4 — Example of a direct acting safety shut-off device . 48
Figure BB.1 — Example for pressure regulator including maximum outlet pressure variations for constant
outlet setting pressure p and lock-up pressure p including typical results . 50
2s 2f
Figure BB.2 — Example for pressure regulator including maximum outlet pressure variations for adjustable
outlet setting pressures p , p , and lock-up pressures p , p , including typical results
2smin 2smax 2fmin 2fmax
..................................................................................................................................................................... 51
Tables
Table 1 — Minimum value of safety factor F . 15
Table 2 — Accuracy classes . 20
Table 3 — Lock-up pressure classes . 21
Table 4 — Specified accuracy classes for over- and under-pressure shut-off devices . 24
Table BB.1 — Setting and performance . 49
Table DD.1 — Comparison between EN 334:2005+A1:2009 and prEN 88-2:2013 . 54
Table ZA.1 — Correspondence between this European Standard and Directive 2009/142/EC relating to
appliances burning gaseous fuels . 55
Table ZB.1 — Correspondence between this European Standard and Directive 97/23/EC concerning pressure
equipment . 57

oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Foreword
This document (prEN 88-2:2014) has been prepared by Technical Committee CEN/TC 58 “Safety and control
devices for burners and appliances burning gaseous or liquid fuels”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 88-2:2007.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA and ZB, which is an integral part of this
document.
For this European Standard a transition period of 3 years is proposed.
It should be noted that the following significant technical changes compared to the previous edition have been
incorporated in this European Standard:
a) scope enlarged to “Pressure regulators incorporating safety devices";
b) alignment with prEN 13611:2012;
c) requirements and tests added for pressure regulators which use auxiliary energy;
d) classifications according to accuracy, lock-up, and overpressure shut-off added;
e) clause 6 enlarged to “Design and construction”;
f) clause 6.2.104 “Integral safety shut-off device” added;
g) clause 6.2.105 “Resistance to pressure” added;
h) clause 6.2.107 “Creep relief device” added;
i) clause 7.3 “Test for leak-tightness”, new value for test pressure;
j) design of all Figures adapted to design of Figures in EN 13611;
k) annex BB “Overview of requirement and test conditions” added;
l) annex CC “Creep relief device” added;
m) annex DD “Comparison between EN 334:2012 and EN 88-2:2013” added.
EN 88 consists of the following parts, under the general title Pressure regulators and associated safety
devices for gas appliances:
 Part 1: Pressure regulators for inlet pressures up to and including 50 kPa
 Part 2: Pressure regulators for inlet pressure above 50 kPa up to and including 500 kPa and associated
safety devices
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Performance Level (PL) or Safety Integrity Level (SIL) classifications according to EN ISO 13849-1 or
EN 61508-1 cannot automatically be claimed based upon compliance with this European Standard. Pressure
regulators with SIL classification do not meet automatically the requirements of this standard.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Introduction
This standard is a particular standard for Pressure Regulators for gas-burners and gas-burning appliances
which cites the generic requirements of prEN 13611:2012 wherever possible. This standard supplements or
modifies the corresponding clauses of prEN 13611:2012. The construction and performance requirements are
as far as applicable in total conformity with prEN 13611:2012.
This document is intended to be used in conjunction with prEN 13611:2012. This document refers to clauses
of prEN 13611:2012 or adapts clauses by stating “with the following modification”, “with the following addition”,
“is replaced by the following” or "is not applicable" in the corresponding clause. This European Standard adds
clauses or sub-clauses to the structure of prEN 13611:2012 which are particular to this European Standard. It
should be noted that these clauses and sub-clauses are not indicated as an addition. Subclauses or annexes
which are additional to those in prEN 13611:2012 are numbered starting from 101 or are designed as
Annex AA, BB, CC, etc.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
1 Scope
This European Standard specifies the safety, construction and performance requirements for pneumatic
pressure regulators and safety devices, intended for use with gas burners, gas appliances and similar use,
hereafter referred to as ‘pressure regulators’.
This European Standard is applicable to:
 pressure regulators with declared maximum inlet pressure above 50 kPa up to and including 500 kPa, of
nominal connection size up to and including DN 250 for use with one or more fuel gases in accordance
with EN 437,
 pressure regulators incorporating safety devices,
 pressure regulators incorporating safety devices specified as safety accessories,
NOTE For safety accessories and pressure accessories, the requirements of prEN 13611:2012, Annex F also
apply.
 pressure regulators which use auxiliary energy,
Pressure regulators intended to be used on pipe work installations for third family gases are also covered by
EN 13785 and EN 13786.
This European Standard is not applicable to:
 pressure regulators that are connected directly to mains pipe-work or to a container that maintains a
standard distribution pressure,
 pressure regulators intended for gas appliances to be installed in the open air and exposed to the
environment,
 safety devices which use auxiliary energy.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 88-1:2011, Pressure regulators and associated safety devices for gas appliances — Part 1: Pressure
regulators for inlet pressures up to and including 50 kPa
EN 549, Rubber materials for seals and diaphragms for gas appliances and gas equipment
EN 682, Elastomeric seals — Materials requirements for seals used in pipes and fittings carrying gas and
hydrocarbon fluids
EN 12267:1999, Industrial valves — Butt welding ends for steel valves
prEN 13611:2012, Safety and control devices for burners and appliances burning gaseous and/or liquid
fuels — General requirements
EN 13785+A1:2008, Regulators with a capacity of up to and including 100 kg/h, having a maximum nominal
outlet pressure of up to and including 4 bar, other than those covered by EN 12864 and their associated
safety devices for butane, propane or their mixtures
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
EN 13786:2010, Automatic change-over valves having a maximum outlet pressure of up to and including
4 bar with a capacity of up to and including 100 kg/h, and their associated safety devices for butane, propane
or their mixtures
EN 13787, Elastomers for gas pressure regulators and associated safety devices for inlet pressures up to
100 bar
EN 13906-1:2002, Cylindrical helical springs made from round wire and bar — Calculation and design —
Part 1: Compression springs
EN 13906-2:2001, Cylindrical helical springs made from round wire and bar — Calculation and design —
Part 2: Extension springs
EN 60534-2-3, Industrial-process control valves — Part 2-3: Flow capacity — Test procedures
(IEC 60534-2-3:1997)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in prEN 13611:2012 and the following
apply.
3.101
pressure regulator
device that maintains the outlet pressure constant independent of the variations in inlet pressure and/or flow
rate within defined limits
[SOURCE: EN 88-1:2011, 3.101]
3.102
control member
movable part of the pressure regulator which varies flow rate and/or outlet pressure directly
[SOURCE: EN 88-1:2011, 3.107]
3.103
safety shut-off device
SSD
device whose function is to stay in the open position under normal operating conditions and to shut off the gas
flow automatically and completely when the monitored pressure deviates above or below the pre-set value
3.104
housing
part of the pressure regulator and/or SSD that is the main pressure containing envelope
3.105
valve seat
corresponding sealing surfaces within a pressure regulator or SSD that make full contact only when the
pressure regulator or SSD is in the closed position
3.106
controller
device which normally includes a setting element, normally a spring, to obtain a set value of the outlet
pressure and a pressure detector element, normally a diaphragm for the outlet pressure
3.107
actuator
device or mechanism which changes the signal from the controller into a corresponding movement controlling
the position of the control member
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
3.108
working diaphragm
flexible member which, under the influence of the forces arising from loading and pressure, operates the
control member
Note 1 to entry: Diaphragms used as control member are not covered by this definition.
3.109
pressure containing parts
parts where failure would result in release of gas to the atmosphere
Note 1 to entry: Such parts comprise housings, inner partition walls, control member, bonnets, the housing of the
actuator, blind flanges and pipes for process and sensing lines.
3.110
signal connection
part that is used to convey pressure from part of an installation to the signal chamber
3.111
breather line
line between the controller and/or pilot regulator and atmosphere which equalizes the pressure on a detector
element when it changes its position
3.112
fixtures
functional devices connected to the main components of the pressure regulator or SSD
3.113
exhaust line
line to atmosphere between the regulator or fixtures for the safe venting of gas in the event of a component
failure
3.114
trip mechanism
mechanism that releases the closure member when activated by the controller
3.115
SSD-actuator
device that is activated by the trip mechanism which shuts the closure member
3.116
relatching device
device that enables the complete opening of an SSD
3.117
motorization chamber
chamber at the higher pressure of two chambers under pressure within the housing of actuator
3.118
monitored pressure
pressure monitored and safeguarded by the SSD
3.119
trip pressure
pressure value at which the closing member starts to move
3.120
upper trip pressure p
do
upper limit of the monitored pressure (over-pressure)
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
3.121
lower trip pressure
p
u
lower limit of the monitored pressure (under pressure)
3.122
outlet setting pressure
p
2s
outlet pressure at which the pressure regulator is set for test purposes
[SOURCE: EN 88-1:2011, 3.113]
3.123
maximum outlet pressure
p
2max
upper limit of the outlet pressure, as stated in the installation and operating instructions
[SOURCE: EN 88-1:2011, 3.109]
3.124
minimum outlet pressure
p
2min
lower limit of the outlet pressure, as stated in the installation and operating instructions
[SOURCE: EN 88-1:2011, 3.110]
3.125
outlet pressure range
difference between minimum and maximum values of the outlet pressure
[SOURCE: EN 88-1:2011, 3.111]
3.126
steady state value
outlet pressure measured after step response (control signal remains constant)
[SOURCE: EN 88-1:2011, 3.127]
3.127
settling tolerance
maximum difference between the current outlet pressure and its steady state value
[SOURCE: EN 88-1:2011, 3.128]
3.128
regulation tolerance
settling tolerance, expressed as a percentage of the outlet setting pressure
3.129
performance curve
graphic representation of the outlet pressure as a function of the rated flow rate
Note 1 to entry: This curve is determined by increasing and then decreasing the rated flow rate with constant inlet
pressure and constant outlet setting pressure (see Figure BB.1).
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
3.130
family of performance curves
set of the performance curves for each value of inlet pressure determined for a given outlet setting pressure
Note 1 to entry: See Figure BB.2.
3.131
accuracy
percentage of the outlet pressure relative to the outlet setting pressure within the operation range
3.132
accuracy class
AC
maximum permissible value of the accuracy
3.133
inlet pressure range
difference between the minimum and maximum values of the inlet pressure
[SOURCE: EN 88-1:2011, 3.108]
3.134
lock-up time
t
f
time taken for the control member to move from an open position to the closed position
3.135
lock-up pressure
p
2f
outlet pressure at which a pressure regulator closes when the outlet of the pressure regulator is sealed
[SOURCE: EN 88-1:2011, 3.120]
3.136
lock-up pressure class
SG
maximum permissible positive difference between the actual lock-up pressure(s) p and the corresponding
2f
outlet setting pressure(s) at a certain percentage of the maximum rated flow rate q expressed as a
max
percentage of the outlet setting pressure
Note 1 to entry: The lock-pressure pressure class, SG, is given by the following equation:
(p − p )
2f 2
SG= 100⋅
p
[1]
where
SG is the lock-up pressure class;
p is the lock-up pressure; and
2f
p is the outlet setting pressure.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
3.137
maximum allowable pressure
PS
maximum pressure for which the pressure regulator and/or SSD is designed as stated in the installation and
operating instructions
Note 1 to entry: In accordance with the strength requirements of this European Standard.
3.138
limit pressure
p
l
pressure at which yielding becomes apparent in any component of the pressure regulator or its fixtures
3.139
safety factor
S , S
b
ratio of the value of the limit pressure p to the value of the maximum allowable pressure PS
l
Note 1 to entry: This term applies to two separate discrete regions of the pressure regulator:
 applied to the pressure regulator housing: S ;
b
 applied to the other pressure containing parts of the pressure regulator: S
4 Classification
4.1 Classes of control
prEN 13611:2012, 4.1 is replaced by the following:
Pressure regulators shall be classified according to regulator accuracy (7.101.2.4) AC 1, AC 2,5, AC 5, AC 10,
and AC 20, according to lock-up pressure (7.101.2.5) SG 5, SG 10, SG 20, and SG 30, and according to
overpressure shut-off accuracy (7.102.1) AG 5, AG 10, AG 20, and AG 30.
4.2 Groups of control
Shall be according to prEN 13611:2012, 4.2 with the following addition:
Pressure regulators shall fulfil Group 2 classification.
4.3 Classes of control function
prEN 13611:2012, 4.3 is not applicable.
4.4 Types of DC supplied controls
prEN 13611:2012, 4.4 is not applicable.
5 Units of measurement and test conditions
Shall be according to prEN 13611:2012, Clause 5.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
6 Design and construction
6.1 General
Shall be according to prEN 13611:2012, 6.1 with the following addition:
If in the event of a failure (e.g. of a diaphragm) leakage is possible, a tapping connection of at least DN 8 for
an exhaust line shall be provided.
6.2 Mechanical parts of the control
6.2.1 Appearance
Shall be according to prEN 13611:2012, 6.2.1.
6.2.2 Holes
Shall be according to prEN 13611:2012, 6.2.2.
6.2.3 Breather holes
Shall be according to prEN 13611:2012, 6.2.3 with the following addition:
If the vented capacity is greater than 70 dm /h of air, a connection for a vent pipe shall be provided.
6.2.4 Test for leakage of breather holes
Shall be according to prEN 13611:2012, 6.2.4.
6.2.5 Screwed fastenings
Shall be according to prEN 13611:2012, 6.2.5.
6.2.6 Jointing
Shall be according to prEN 13611:2012, 6.2.6.
6.2.7 Moving parts
Shall be according to prEN 13611:2012, 6.2.7.
6.2.8 Sealing caps
Shall be according to prEN 13611:2012, 6.2.8.
6.2.9 Dismantling and reassembly
Shall be according to prEN 13611:2012, 6.2.9.
6.2.10 Auxiliary canals and orifices
Shall be according to prEN 13611:2012, 6.2.10.
6.2.11 Presetting device
Shall be according to prEN 13611:2012, 6.2.11.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
6.2.101 External visual Indication of the position of the closure member
If an external visual device to indicate the closure member position, is fitted to an SSD, it shall clearly indicate
whether it is in the open or closed position.
6.2.102 Parts transmitting actuating forces
Parts transmitting actuating forces shall be metallic and designed with a safety factor of ≥3 against permanent
deformation.
6.2.103 Adjustments
The adjustments (e.g. outlet pressure, offset and gas/air-ratio) shall be readily accessible to authorised
persons, but there shall be provision for sealing after adjustment. Means shall be provided to discourage
interference by unauthorised persons. If it is stated in the installation and operating instructions that a
pressure regulator can be put out of action, appropriate means shall be provided to put the pressure regulator
out of action.
6.2.104 Integral safety shut-off device
An integral safety shut-off device shall be functionally independent from the regulator.
This requirement is met if the function of the safety shut-off device is not affected in the event of failure and/or
loss of functionality of one or more of the following regular components:
 Control member;
 Seat ring;
 Actuator;
 Casing of actuator;
 Controller;
 Pilot (for pilot-controlled regulator types);
 Sensing and process lines.
If the regulator incorporates more than one safety device the functional independence shall be met by each
device.
When the integral safety shut-off device utilizes pipeline gas as a source of energy for its operation this shall
be taken from upstream of the pressure regulator. For any kind of pneumatic automation system there shall be
no bypass around the safety shut-off device, also taking fault conditions into account.
6.2.105 Resistance to pressure
Parts of the pressure regulator that are subjected to inlet pressure under normal operating conditions, or could
be subjected to inlet pressure in the event of a failure, shall resist a pressure equal to the maxium allowable
pressure (PS).
6.2.105.1 Requirement
Parts of the pressure regulator that are subjected to inlet pressure under normal operating conditions, or could
be subjected to inlet pressure in the event of a failure, shall resist a pressure equal to the maximum allowable
pressure (PS) multiplied by a safety factor F.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Following safety factors shall be used:
Table 1 — Minimum value of safety factor F
Group of materials Minimum value of safety factor F
For parts of the body stressed by
forces from torque and bending

moments (pipelines) only
Rolled and forged steel 1,70 2,13
Cast steel 2,00 2,50
Spheroidal graphite cast iron and 2,50 3,13
malleable cast iron
Copper-zinc wrought alloys and 2,00 2,50
aluminium alloys
Copper-tin cast alloys and copper- 2,50 3,13
zinc cast alloys
Aluminium cast alloys 2,50 3,13
Amin 4%
Aluminium cast alloys 3,20 4,00
Amin 1,5%
After the test there shall be no visible damage.
6.2.105.2 Test
The hydrostatic pressure test is conducted after leakage and function tests. A pressure of F times the
maximum allowable pressure (PS) is applied to the control for a minimum of 5 min.
6.2.106 Signal tube connections
Requirements on connections for gas pressure, air pressure or furnace pressure signal tubes shall be stated
in the installation and operating instructions.
6.2.107 Creep relief device
A creep relief device can only be built into the spring-operated regulator to vent the gas to the atmosphere
when the controlled pressure is higher than the lock-up pressure of the regulator with a limited capacity (see
Annex CC).
6.3 Materials
6.3.1 General material requirements
Shall be according to prEN 13611:2012, 6.3.1 with the following addition:
Closure members shall conform to prEN 13611:2012, Annexes F to H.
Elastomers and vulcanized rubber shall conform to 7.8.1.
6.3.2 Housing
Shall be according to prEN 13611:2012, 6.3.2 with the following addition:
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Materials shall conform to prEN 13611:2012, Annexes F to H.
6.3.3 Zinc alloys
prEN 13611:2012, 6.3.3 is replaced by:
Zinc alloys shall not be used.
6.3.4 Springs providing closing and/or sealing force
Shall be according to prEN 13611:2012, 6.3.4. .
6.3.5 Resistance to corrosion and surface protection
Shall be according to prEN 13611:2012, 6.3.5.
6.3.6 Impregnation
Shall be according to prEN 13611:2012, 6.3.6.
6.3.7 Seals for glands for moving parts
Shall be according to prEN 13611:2012, 6.3.7.
6.4 Gas connections
Shall be according to prEN 13611:2012, 6.4.
6.5 Electrical parts of the control
prEN 13611:2012, 6.5 is not applicable.
6.6 Protection against internal faults for the purpose of functional safety
prEN 13611:2012, 6.6 is not applicable.
7 Performance requirements
7.1 General
Shall be according to prEN 13611:2012, 7.1.
7.2 Leak-tightness
Shall be according to prEN 13611:2012, 7.2, with the following addition:
All pressure containing parts and all connecting joints of pressure regulators shall be leak-tight according to
prEN 13611:2012, F.7.12.
7.3 Test for leak-tightness
7.3.1 General
Shall be according to prEN 13611:2012, 7.3.1.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
For external leakage carry out the test with 1,5 times x PS (maximal allowable pressure) at the inlet and outlet
and on the atmospheric side of the working diagram (including the safety diaphragm, if any). If applicable the
additional test conditions of 7.3.1 shall be taken into account.
The test results shall meet the requirements of 7.2.
7.3.2 External leak-tightness
Shall be according to prEN 13611:2012, 7.3.2, with the following addition:
If applicable the additional test conditions of 7.3.1 shall be taken into account.
7.3.3 Internal leak-tightness
prEN 13611:2012, 7.3.3 is replaced by the following:
This test is only applicable for SSDs and shall be carried out with the pressure regulator, if any, in the open
position.
With any closure member in the closed position, pressurize the inlet of the pressure regulator in the direction
of gas flow indicated, to two different pressures, 10 kPa and 1,5 x PS, and measure the leakage rate.
The internal leakage test of the assembled SSD and its fixtures shall be carried out with two different
pressures, 10 kPa and 1,5 PS, upstream of the closure member and at atmospheric pressure downstream of
the closure member.
7.4 Torsion and bending
Shall be according to prEN 13611:2012, 7.4.
7.5 Torsion and bending tests
Shall be according to prEN 13611:2012, 7.5.
7.6 Rated flow rate
Shall be according to prEN 13611:2012, 7.6 with the following addition:
The requirement for the rated flow rate is only applicable for safety shut-off devices without regulator.
7.7 Test for rated flow rate
Shall be according to prEN 13611:2012, 7.7 with the following addition:
The test for the rated flow rate is only applicable for safety shut-off devices without regulator.
7.8 Durability
7.8.1 Elastomers in contact with gas
Shall be according prEN 13611:2012, 7.8.1 with the following modification:
Elastomers and vulcanized rubber in contact with gas (e.g. valve pads, O-rings, diaphragms and lip seals)
shall comply with requirements and tests given in EN 549:1994, or EN 682, or prEN 13611, Annex O, or
EN 13787.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
7.8.2 Marking
Shall be according to prEN 13611:2012, 7.8.2.
7.8.3 Resistance to scratching
Shall be according to prEN 13611:2012, 7.8.3.
7.8.4 Resistance to humidity
Shall be according to prEN 13611:2012, 7.8.4.
7.9 Performance tests for electronic controls
prEN 13611:2012, 7.9 is not applicable.
7.10 Long-term performance for electronic controls
prEN 13611:2012, 7.10 is not applicable.
7.11 Data exchange
prEN 13611:2012, 7.11 is not applicable.
7.101 Pressure regulator performance
7.101.1 General
If more than one function exists (e.g. pressure regulator and integral safety shut-off device) then the
performance of each function shall be considered separately.
If the pressure regulator has built-in safety device(s) it shall be tested with the safety device(s) in its (their)
normal operating position.
The external sensing/process lines shall be located on the downstream pipework as stated in the installation
and operating instructions.
7.101.2 General test procedure
7.101.2.1 Apparatus
The tests shall be carried out on a test rig built as specified in Figure 1 or in accordance with EN 60534-2-3 as
appropriate. The nominal diameter of the pipework connecting the pressure regulator inlet and the flow rate
regulating valves with the pressure regulator shall not be smaller than the nominal diameter of the pressure
regulator and so chosen as to ensure that in all operating conditions of the tests the velocity of the gas does
not exceed 50 m/s for pressures ≥ 50 kPa.
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
Dimensions in millimetres
Key
Nominal size Internal diameter
1 Inlet pressure gauge p
1 (DN) (mm)
2 Outlet pressure gauge p
6 6
3 Adjustable regulator for inlet pressure
8 9
4 Inlet temperature gauge
10 13
5 Outlet temperature gauge
15 16
6 Flow meter, positioned at inlet or outlet
20 22
7 Pressure regulator under test
25 28
8 Manual control tap for flow adjustment
32 35
9 Hole, 4 holes à Ø 1,5 mm
40 41
a
The connection possibility for an application is voluntary. 50 52
The size of the outer diameter is given as an example and may 65 67
vary if applicable.
80 80
100 106
125 131
150 159
200 209
250 260
Figure 1 — Performance test apparatus
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
The uncertainty of measurement shall not exceed 2 %. Pressure gauges shall have an accuracy of at least
AC/4 (in %) in the range of the scale according to the applicable standard and a full scale not greater than
twice the value of the variable to be measured.
The lock-up pressure tests shall always be carried out on a test rig in which the downstream pipework has the
minimum specified length; for these tests an additional downstream volume is not permitted. The flow meter
shall be installed in accordance with its instructions.
7.101.2.2 Conversion of the air flow rate
Shall be according to prEN 13611:2012, 7.7.3.
7.101.2.3 Methods of test
Pressure regulators shall be tested according to
 accuracy class, 7.101.2.4 and
 lock up pressure class, 7.101.2.5.
Tests shall be carried out with air at ambient temperature.
Steady state conditions shall always be reached before readings are taken. Examples of performance curves
are shown in Figures BB.1 and BB.2.
7.101.2.4 Accuracy class
7.101.2.4.1 Requirement
Over the full range of inlet pressure from p to p and over the whole rated flow rate range from q to
1min 1max min
q as stated in the installation and operating instructions the outlet pressure variation from the outlet setting
max
pressure p shall not exceed the values given in Table 1. The stated minimum rated flow rate q shall not
2s min
exceed 10 % of q .
max
When tested in accordance with 7.101.2.4.2, pressure regulators shall conform to accuracy requirements
relevant to the declared accuracy class chosen from Table 1 within the declared class.
Table 2 — Accuracy classes
Accuracy class Maximum regulation tolerance
AC 1 ± 1 %
AC 2,5 ± 2,5 %
AC 5 ± 5 %
AC 10 ± 10 %
AC 20 ± 20 %
NOTE The same type of pressure regulator may have different accuracy classes depending on the outlet pressure
range and/or the inlet pressure range, as stated in the installation and operating instructions.
7.101.2.4.2 Test
To determine the variation of the inlet pressure p and of the flow rate q for a performance curve, proceed as
follows (see also Table 1):
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
a) Adjust the outlet pressure setting of the pressure regulator. Set the outlet control tap to obtain a flow rate
of 0,5 q (or any other value which is appropriate). For adjustable pressure regulators, adjust the outlet
max
pressure setting to the maximum value (p ), the inlet pressure p being the nominal pressure (or any
2max 1
other value) as stated in the installation and operating instructions. After the outlet pressure being set,
there shall be no further adjustment of the pressure regulator.
b) Vary the inlet pressure p from the nominal pressure over the minimum (p ) to the maximum value
1 1min
(p ) as stated in the installation and operating instructions and back to p , and record the outlet
1max 1min
pressure p for, at least, 5 values of p in each direction, without resetting the flow rate.
2 1
c) With inlet pressure p kept constant, vary the flow rate from q to q and back by using the outlet
1min max min
control tap, the outlet pressure p being recorded for, at least, 5 values of q in each case. Make sure that
there is no change of the inlet pressure during the whole time of this procedure.
d) Readjust the inlet pressure from p to p as stated in the installation and operating instructions and
1min 1max
then vary the flow rate from q to q (as in step c)).
max min
e) For adjustable pressure regulators, repeat steps b) to d) after the outlet pressure setting has been
readjusted according to step a) to the value p .
2min
The determination is based on optimal enveloping of each family of performance curves with the vertical and
horizontal limit lines as shown in Figures BB.1 and BB.2. Examples of optimal enveloping procedures are
shown in Figures BB.1 and BB.2 and are described as follows:
 plot the performance curves of a family in a semilog diagram with rated flow rates on the decimal scale of
the abscissa and outlet pressure on the logarithmic scale of the ordinate;
 locate on this diagram, in an optimized manner, three dashed lines spaced as shown in Figures BB.1 and
BB.2; the optimization of the location of these lines is reached when the greatest possible number of
performance requirements are met;
 identify the actual outlet setting pressure where the horizontal line intersects the ordinate;
 ensure that q , q , q , q , AC and p are as stated in the operation and
max,p1min max,p1max min,p1max min,p1min 2f
installation instructions.
NOTE Other equivalent optimal enveloping methods may be used.
7.101.2.5 Lock-up pressure class
7.101.2.5.1 Requirement
When a pressure regulator, as stated in the installation and operating instructions, has the ability to lock-up,
the outlet pressure shall not rise by more than stated in Table 2. Such a pressure regulator shall be tested in
accordance with the test method described in 7.101.2.5.2.
Table 3 — Lock-up pressure classes
Lock-up pressure class Maximum regulation tolerance within the lock-up pressure
zone
SG 5 5 %
SG 10 10 %
SG 20 20 %
SG 30 30 %
oSIST prEN 88-2:2015
prEN 88-2:2014 (E)
NOTE The same type of pressure regulator may have different lock-up pressure groups depending on the outlet
pressure range and/or the inlet pressure range, as stated in the installation and operating instructions.
7.101.2.5.2 Test
When a pressure regulator, as stated in the installation and operating instructions, has the ability to lock-up,
an additional measurement at zero rated flow rate shall be taken for each pair of p and p values.
1 2s
The lock-up pressure shall be determined in connection with tests carried out to determine the performance
curve of the outlet pressure. The time required to reduce the rated flow rate to zero shall not be less than the
lock-up time of the pressure regulator. This condition is deemed to be satisfied when the lock-up pressure is
found to be independent of the time needed to reduce the rated flow rate to zero (see Figure 2).

Key
t Time
p Lock-up pressure
2f
p Outlet pressure with control member at
t Lock-up time
f
closure position
Figure 2 — Graphical representation of 7.101.2.5.2
The
...