SIST EN 88-2:2008

SLOVENSKI STANDARD
SIST EN 88-2:2008
01-januar-2008
7ODþQLUHJXODWRUMLLQSULSDGDMRþHYDUQRVWQHQDSUDYH]DSOLQVNHDSDUDWHGHO
7ODþQLUHJXODWRUML]DYVWRSQHWODNHQDGEDUGRYNOMXþQREDU
Pressure regulators and associated safety devices for gas appliances - Part 2: Pressure
regulators for inlet pressures above 500 mbar up to and including 5 bar
Druckregler und zugehörige Sicherheitseinrichtungen für Gasgeräte - Teil 2: Druckregler
für Eingangsdrücke über 500 mbar bis einschließlich 5 bar
Régulateurs de pression et dispositifs de sécurité associés pour appareils a gaz - Partie
2: Régulateurs de pression pour pression amont supérieure a 500 mbar et inférieure ou
égale a 5 bar
Ta slovenski standard je istoveten z: EN 88-2:2007
ICS:
23.060.40 7ODþQLUHJXODWRUML Pressure regulators
SIST EN 88-2:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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EUROPEAN STANDARD
EN 88-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2007
ICS 23.060.40

English Version
Pressure regulators and associated safety devices for gas
appliances - Part 2: Pressure regulators for inlet pressures
above 500 mbar up to and including 5 bar
Régulateurs de pression et dispositifs de sécurité associés Druckregler und zugehörige Sicherheitseinrichtungen für
pour appareils à gaz - Partie 2: Régulateurs de pression Gasgeräte - Teil 2: Druckregler für Eingangsdrücke über
pour pression amont supérieure à 500 mbar et inférieure ou 500 mbar bis einschließlich 5 bar
égale à 5 bar
This European Standard was approved by CEN on 8 May 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 88-2:2007: E
worldwide for CEN national Members.

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EN 88-2:2007 (E)
Contents Page
Foreword. 4
Introduction . 5
1 Scope. 6
2 Normative references . 6
3 Terms and definitions. 7
3.1 Pressure regulator . 7
3.2 Components . 7
3.3 Safety shut-off devices. 9
3.4 Control variables. 10
3.4.1 Reference values. 10
3.4.2 Variables in the controlling process. 11
3.4.3 Possible values of all variables . 11
3.4.4 Terms pertinent to the controlled variable. 12
3.5 Operating features in stable conditions . 12
3.6 Features pertinent to accuracy. 14
3.7 Features pertinent to lock-up behaviour . 15
3.8 Further functional terminology. 16
3.8.1 Pressures pertinent to design of gas pressure regulator. 16
3.8.2 nominal pressure . 17
3.8.3 operating temperature range temperature range at which the pressure regulator
components and fixtures are capable of operating continuously. 17
4 Classification. 17
5 Units of measurement and test conditions . 17
5.1 Units of measurement . 17
5.2 Test conditions. 17
6 Construction requirements. 18
6.1 General. 18
6.2 Construction. 18
6.2.1 General. 18
6.2.2 Breather holes . 18
6.2.3 External visual Indication of the position of the closure member. 18
6.2.4 Parts transmitting actuating forces . 19
6.2.5 Pressure adjustment. 19
6.3 Materials. 19
6.3.1 General. 19
6.3.2 Springs. 19
6.3.3 Requirements for elastomers (including vulcanized rubbers). 19
6.4 Gas connections . 19
6.4.1 General. 19
6.4.2 Connection sizes. 19
6.4.3 Threads . 20
6.4.4 Pressure test nipples (applicable only for outlet connections operating at ≤
500 mbar) . 20
7 Performance requirements . 20
7.1 General. 20
7.2 Strength of housings. 20
7.2.1 Requirement . 20
7.2.2 Performance test. 21
7.3 External and internal leak tightness . 21
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EN 88-2:2007 (E)
7.4 Torsion and bending. 21
7.5 Control classification. 21
7.5.1 General. 21
7.5.2 Control classifications for pressure regulators. 21
7.5.3 Safety shut-off device accuracy group for over-pressure. 22
7.6 Safety devices . 22
7.6.1 Over-pressure safety shut-off device . 22
7.6.2 Under-pressure safety shut-off devices . 23
7.6.3 Bypass. 23
7.6.4 Response time. 23
7.7 Durability of performance . 23
7.7.1 Pressure regulator . 23
7.7.2 Safety slam-shut device . 23
8 Marking, installation and operating instructions. 24
8.1 Marking . 24
8.2 Installation, operating and servicing instructions. 24
8.3 Warning notice . 25
Annex A (informative) Main components for direct acting and pilot controlled pressure
regulators. 26
A.1 Main components of a pressure regulator . 26
A.2 Main components of a gas safety shut-off device. 27
Annex B (informative) Use of ISO 7-1 and EN ISO 228-1 threads for gas connections (see
6.4.3) . 29
Annex C (normative) Performance test methods . 30
C.1 General. 30
C.2 Apparatus and test rig. 30
C.3 Performance tests under stable conditions. 32
C.3.1 General. 32
C.3.2 Determination of a performance curve. 34
C.3.3 Determination of the lock-up pressure. 35
C.3.4 Regulator accuracy class. 36
C.4 Safety shut-off device accuracy group. 37
C.4.1 General conditions and apparatus. 37
C.4.2 Test at ambient temperature. 39
C.4.3 Test at the limit temperatures between 0 ºC and 60 ºC. 39
C.4.4 Verification of the upper limit of the highest set range . 40
C.4.5 Response time. 40
C.5 Durability of performance . 41
C.5.1 General. 41
C.5.2 Pressure regulator . 41
C.5.3 Safety shut-off devices. 42
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 90/396/EEC. 43
Bibliography . 45

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EN 88-2:2007 (E)
Foreword
This document (EN 88-2:2007) has been prepared by Technical Committee CEN/TC 58 “Safety and
control devices for gas-burners and gas-burning appliances”, 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 May 2008, and conflicting national standards shall be
withdrawn at the latest by May 2008.
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, which is an integral part of this
document.
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 500 mbar;
Part 2: Pressure regulators for inlet pressures above 500 mbar up to and including 5 bar.
This European Standard should be used in conjunction with EN 13611 ‘’Safety and control devices for
gas burners and gas burning appliances — General requirements.’’
SIL classification according to EN 61508 cannot automatically be claimed based upon compliance
with this standard. Pressure regulators with SIL classification do not meet automatically the
requirements of this standard.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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EN 88-2:2007 (E)

Introduction
This standard is a particular standard for Pressure Regulators for gas-burners and gas-burning
appliances which cites EN 13611 ‘’Safety and control devices for gas burners and gas-burning
appliances - General requirements’’ wherever possible. This standard supplements or modifies the
corresponding clauses of EN 13611. The construction and performance requirements are as far as
applicable in total conformity with EN 13611.
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EN 88-2:2007 (E)

1 Scope
This European Standard specifies the safety, construction and performance requirements for pressure
regulators (hereafter referred to as regulators) intended for use with gas burners and gas-burning
st nd rd
appliances using fuel gases of the 1 , 2 and 3 families. This European Standard covers type
testing only. It also provides additional information for the purchaser and user.
This European Standard is applicable to regulators that may be tested independently of gas burners
and gas-burning appliances, which have a declared working pressure from above 500 mbar up to and
including 5 bar.
This European Standard is also applicable to regulators incorporating safety devices.
NOTE 1 For safety accessories and pressure accessories, the requirements of EN 13611:2007, Annex F also
apply.
NOTE 2 Regulators conforming to EN 88-2 fulfil also the requirements of EN 88-1.
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:
a) pressure regulators that are connected directly to mains pipe-work or to a container that
maintains a standard distribution pressure;
b) pressure regulators which use electrical auxiliary energy.
2 Normative references
The following referenced documents are indispensable for the application 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 88-1:2007, Pressure regulators and associated safety devices for gas appliances — Part 1:
Pressure regulators for inlet pressures up to and including 500 mbar
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 13611:2007, Safety and control devices for gas burners and gas burning appliances — General
requirements
EN 13787, Elastomers for gas pressure regulators and associated safety devices for inlet pressures
up to 100 bar
EN 60534-1:2005, Industrial-process control valves — Part 1: Control valve terminology and general
considerations (IEC 60534-1:2005)
EN 60534-2-3, Industrial-process control valves — Part 2-3: Flow capacity — Test procedures (IEC
60534-2-3:1997)
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EN 88-2:2007 (E)
EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1:
Dimensions, tolerances and designation (ISO 228-1:2000)
EN ISO 6708, Pipework components — Definition and selection of DN (nominal size) (ISO
6708:1995)
ISO 7-1, Pipe threads where pressure tight joints are made on the threads —
Part 1: Designation, dimensions and tolerances
ISO 3419, Non-alloy and alloy steel butt-welding fittings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13611:2007, EN 60534-
1:2005 and the following apply.
3.1 Pressure regulator
3.1.1
pressure regulator
device that maintains the outlet pressure constant independent of the variations in inlet pressure
and/or flow rate within defined limits
3.1.2
nominal inlet diameter
nominal size DN of the inlet connection in accordance with EN ISO 6708
3.1.3
nominal outlet diameter
nominal size DN of the outlet connection in accordance with EN ISO 6708
3.2 Components
NOTE The main components of a pressure regulator and a safety shut-off device are shown in Annex A.
3.2.1
control member
movable part of the pressure regulator that is positioned in the flow path to restrict the flow through
the pressure regulator
NOTE A control member may be a plug, ball, disk, vane, gate, diaphragm, etc.
3.2.2
body
part of the pressure regulator that is the main pressure containing envelope
3.2.3
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
3.2.4
seat ring
replaceable component of a regulator valve seat assembly
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EN 88-2:2007 (E)
3.2.5
actuator
device or mechanism which changes the signal from the controller into a corresponding movement
controlling the position of the control member
3.2.6
casing of actuator
housing of the actuator
NOTE There may be two chambers under pressure within it. When the pressure in each chamber is
different from atmospheric pressure, the chamber at the higher pressure is termed the "motorization chamber"
3.2.7
controller
device that controls the regulator
NOTE It includes:
 setting element, normally a spring, to obtain the set value of the controlled variable;
 detector element, normally a diaphragm, for the controlled variable.
3.2.8
pilot controller
device that controls the regulator
NOTE It includes:
 setting element to obtain the set value of the controlled variable;
 detector element for the controlled variable;
 unit which compares the set value of the controlled variable with its feedback value;
 system which provides the motorization energy for the actuator.
3.2.9
main diaphragm
device that detects the controlled variable feedback pressure and provides the force to position the
valve
3.2.10
pressure containing parts
parts where failure would result in release of gas to the atmosphere
NOTE Such parts comprise bodies, control member, bonnets, the casing of the actuator, blind flanges and
pipes for process and sensing lines.
3.2.11
inner metallic partition wall
metallic wall that divides internal chambers which have differing operating pressures
3.2.12
process and sensing line
line that connects impulse points to the pressure regulator
NOTE Sensing and process lines may be integrated into the pressure regulator or external to the pressure
regulator. Those lines with no internal flow are termed "sensing lines"; those with internal flow are termed
"process lines".
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EN 88-2:2007 (E)
3.2.13
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
3.2.14
exhaust line
line to atmosphere between the regulator or fixtures for the safe venting of gas in the event of a
component failure
3.2.15
fixtures
functional devices connected to the main components of the pressure regulator or SSD
3.3 Safety shut-off devices
3.3.1
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
3.3.2
closure member
movable part of the safety shut off device that shuts off the gas flow
3.3.3
trip mechanism
mechanism that releases the closure member when activated by the controller
3.3.4
actuator
device that is activated by the trip mechanism which shuts the closure member
3.3.5
relatching device
device that enables the complete opening of an SSD
3.3.6
safety shut-off device controller
safety device for the regulator
NOTE It may include:
 setting element to adjust the set value of the trip pressure;
 sensing element for the control of the monitored pressure (e.g. a diaphragm);
 unit which compares the set value of the trip pressure with the monitored pressure;
 system which gives the energy to operate the trip mechanism.
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EN 88-2:2007 (E)
3.4 Control variables
3.4.1 Reference values
3.4.1.1 Pressure
NOTE All pressures specified in this European Standard are static gauge pressures. They are measured in
1)
bar .
3.4.1.1.1
inlet pressure
p
e

gas pressure at the inlet of the pressure regulator
3.4.1.1.2
outlet pressure
p
a

gas pressure at the outlet of the pressure regulator
3.4.1.1.3
differential pressure
∆p
difference between values of pressure measured at two different points
3.4.1.1.4
motorization pressure,
p
m

gas pressure in the motorization chamber
3.4.1.1.5
motorization chamber
chamber at the higher pressure of two chambers under pressure within the casing of actuator
3.4.1.1.6
pilot feeding pressure
p
ep

gas pressure at the inlet of the pilot
3.4.1.2 Flow conditions
3.4.1.2.1
normal conditions
absolute pressure p of 1 013,25 mbar and temperature T of 0 °C (273,15 K)
n n
NOTE For calculation purposes a value of 273 K is used in this European Standard.
3.4.1.2.2
gas volume
volume of gas at normal conditions
3
NOTE It is expressed in m .
3.4.1.2.3
volumetric flow rate
Q
volume of gas which flows through the pressure regulator in unit time

5 2 5 -1
1) 1 bar = 1000 mbar = 10 N/m = 10 Pa = 10 MPa.
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EN 88-2:2007 (E)
3
NOTE It is expressed in m /h at normal conditions.
3.4.2 Variables in the controlling process
3.4.2.1
controlled variable
X
variable which is monitored by the controlling process
NOTE 1 This controlled variable in pressure regulators may be:
inlet pressure, p
e
 ;
outlet pressure, p
a
 ;
 differential pressure, ∆p.
NOTE 2 In this European Standard, only the outlet pressure "p " is considered as the controlled variable.
a
3.4.2.2
disturbance variable
Z
variables acting from outside on the controlling process
NOTE In the case of pressure regulators with the outlet pressure as the controlled variable, the disturbance
variables are essentially:
fluctuations in the inlet pressure, p
e
 ;
 changes in the volumetric flow rate, Q.
3.4.2.3
monitored pressure
pressure monitored and safeguarded by the SSD
3.4.2.4
trip pressure
pressure value at which the closing member starts to move
3.4.2.5
upper trip pressure
p
o
upper limit of the monitored pressure (over-pressure)
3.4.2.6
lower trip pressure
p
u
lower limit of the monitored pressure (under pressure)
3.4.3 Possible values of all variables
3.4.3.1
actual value
instantaneous value of any variable at any instant
NOTE It is specified by the subscript "i" added to the symbol of the variable
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EN 88-2:2007 (E)
3.4.3.2
maximum value
highest value to which any variable can be adjusted, limited or reached during a series of
measurements or during a certain time period
NOTE It is specified by the subscript "max" added to the symbol o
...