LPG equipment and accessories - Pressure relief valves for LPG pressure vessels - Ancillary equipment

This document specifies the design, testing and inspection requirements for pressure relief valve isolating devices, valve manifolds, vent pipes and system assemblies which are, where necessary, used with pressure relief valves for use in static pressure vessels for Liquefied Petroleum Gas (LPG) service.
This document addresses both prototype testing and production testing of isolating devices and PRV manifolds.
Pressure relief valves for LPG pressure vessels are specified in EN 14129:2014.

Flüssiggas-Geräte und Ausrüstungsteile - Druckentlastungsventile für Druckbehälter für Flüssiggas (LPG) - Zusatzausrüstung

Dieses Dokument legt die Anforderungen an die Auslegung, Prüfung und Inspektion von Sicherheitsven-til Schließeinrichtungen, Sicherheitsventilverteilern, Abblaseleitungen und Systembaugruppen fest, welche bei Bedarf zusammen mit Sicherheitsventilen für ortsfeste Druckbehälter für den Betrieb mit Flüssiggas (LPG, en: Liquefied Petroleum Gas) verwendet werden.
Dieses Dokument behandelt sowohl die Prototyp Prüfung als auch die fertigungsbegleitende Prüfung von Schließeinrichtungen und Sicherheitsventilverteilern.
Sicherheitsventile für Druckbehälter für Flüssiggas (LPG) sind in EN 14129:2014 festgelegt.

Équipements pour GPL et leurs accessoires - Soupapes de sécurité des réservoirs de gaz de pétrole liquéfié (GPL) - Équipement auxiliaire

Le présent document spécifie les exigences en matière de conception, essais et inspection relatives aux clapets porte-soupape, collecteurs de soupapes, prolongateurs de soupapes et systèmes d'assemblage utilisés, lorsque nécessaire, avec les soupapes de sécurité destinées à être installées sur des réservoirs sous pression statiques contenant du gaz de pétrole liquéfié (GPL).
Le présent document traite à la fois des essais sur prototype et des essais de production des clapets porte-soupape et des collecteurs de soupapes.
Les soupapes de sécurité pour réservoirs GPL sous pression sont spécifiées dans l'EN 14129:2014.

Oprema in pribor za utekočinjeni naftni plin (UNP) - Varnostni ventili za tlačne posode za UNP - Pomožna oprema

General Information

Status
Not Published
Current Stage
4020 - Submission to enquiry - Enquiry
Due Date
11-Mar-2021
Completion Date
11-Mar-2021

RELATIONS

Buy Standard

Draft
prEN 14071:2021
English language
24 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 14071:2021
01-marec-2021
Oprema in pribor za utekočinjeni naftni plin (UNP) - Varnostni ventili za tlačne
posode za UNP - Pomožna oprema

LPG equipment and accessories - Pressure relief valves for LPG pressure vessels -

Ancillary equipment

Flüssiggas-Geräte und Ausrüstungsteile - Druckentlastungsventile für Druckbehälter für

Flüssiggas (LPG) - Zusatzausrüstung

Équipements pour GPL et leurs accessoires - Soupapes de sécurité des réservoirs de

gaz de pétrole liquéfié (GPL) - Équipement auxiliaire
Ta slovenski standard je istoveten z: prEN 14071
ICS:
23.020.32 Tlačne posode Pressure vessels
23.060.40 Tlačni regulatorji Pressure regulators
oSIST prEN 14071:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 14071:2021
---------------------- Page: 2 ----------------------
oSIST prEN 14071:2021
DRAFT
EUROPEAN STANDARD
prEN 14071
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2021
ICS Will supersede EN 14071:2015+A1:2019
English Version
LPG equipment and accessories - Pressure relief valves for
LPG pressure vessels - Ancillary equipment

Équipements pour GPL et leurs accessoires - Soupapes Flüssiggas-Geräte und Ausrüstungsteile -

de sécurité des réservoirs de gaz de pétrole liquéfié Druckentlastungsventile für Druckbehälter für

(GPL) - Équipement auxiliaire Flüssiggas (LPG) - Zusatzausrüstung

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 286.

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, 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, 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: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14071:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 7

4 Operating conditions ..................................................................................................................................... 9

5 Materials ............................................................................................................................................................. 9

5.1 General ................................................................................................................................................................ 9

5.2 Metallic materials ........................................................................................................................................... 9

5.3 Non-metallic components ......................................................................................................................... 10

5.4 Lubricants, sealants, and adhesives ...................................................................................................... 10

5.5 Inspection Documents ................................................................................................................................ 10

6 Design ............................................................................................................................................................... 11

6.1 Introduction ................................................................................................................................................... 11

6.2 Pressure relief valve isolating devices ................................................................................................. 11

6.2.1 General ............................................................................................................................................................. 11

6.2.2 Actuation ......................................................................................................................................................... 11

6.2.3 Indication of closure ................................................................................................................................... 11

6.2.4 Guiding arrangements ................................................................................................................................ 12

6.2.5 Isolating mechanism security .................................................................................................................. 12

6.2.6 Interchangeability ....................................................................................................................................... 12

6.3 PRV manifold ................................................................................................................................................. 12

6.3.1 General ............................................................................................................................................................. 12

6.3.2 Indication of port closure .......................................................................................................................... 15

6.3.3 Port closure .................................................................................................................................................... 15

6.4 Vent pipe ......................................................................................................................................................... 15

6.4.1 Design ............................................................................................................................................................... 15

6.4.2 Materials .......................................................................................................................................................... 15

6.4.3 Effect from external conditions............................................................................................................... 15

6.5 Connections .................................................................................................................................................... 15

6.6 Threads ............................................................................................................................................................ 15

6.7 Minimum requirements for springs ...................................................................................................... 16

7 Testing of the design ................................................................................................................................... 16

7.1 General ............................................................................................................................................................. 16

7.2 Test requirements ....................................................................................................................................... 16

7.3 Hydraulic proof test .................................................................................................................................... 17

7.4 Relief valve isolator test ............................................................................................................................ 17

7.5 Testing of audible signal of isolating devices and residual flow of isolating devices

and PRV manifolds ....................................................................................................................................... 17

7.6 Resistance of the isolating mechanism ................................................................................................ 17

7.7 Over-torque deformation test ................................................................................................................. 17

7.8 Operation test ................................................................................................................................................ 18

7.8.1 General ............................................................................................................................................................. 18

7.8.2 System test ...................................................................................................................................................... 18

7.9 Stress cracking test ...................................................................................................................................... 18

---------------------- Page: 4 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)

7.9.1 General ............................................................................................................................................................. 18

7.9.2 Mercury(I)nitrate immersion test .......................................................................................................... 18

7.9.3 Moist ammonia air stress cracking test ................................................................................................ 18

8 Production testing of isolating devices and PRV manifolds .......................................................... 18

9 Marking and labelling ................................................................................................................................. 19

9.1 PRV isolating device .................................................................................................................................... 19

9.2 Pressure relief valve PRV manifolds...................................................................................................... 19

10 User instructions........................................................................................................................................... 19

10.1 PRV isolating devices .................................................................................................................................. 19

10.2 PRV manifolds ................................................................................................................................................ 20

Annex A (normative) Dimensions of master test pieces for PRV and isolating devices ................... 21

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2014/68/EU (Pressure equipment Directive) aimed to be

covered ............................................................................................................................................................. 23

Bibliography ................................................................................................................................................................. 24

---------------------- Page: 5 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
European foreword

This document (prEN 14071:2021) has been prepared by Technical Committee CEN/TC 286 “LPG

equipment and accessories”, the secretariat of which is held by NSAI.
This document is currently submitted to the CEN Enquiry.

This document has been prepared under a standardization request 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.
This document will supersede EN 14071:2015+A1:2019.
The major changes in comparison to the previous edition include:
— Revision of 5.2 Metallic materials;
— Revision to the resistance of the isolating mechanism test;
— Revision of the Kd value for M 36;
— Revision of Annex ZA.
---------------------- Page: 6 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
Introduction

This document calls for the use of substances and procedures that may be injurious to health and/or the

environment if adequate precautions are not taken. It refers only to technical suitability: it does not

absolve the user from their legal obligations at any stage.

It is recommended that manufacturers develop an environmental management policy. For guidance, see

the EN ISO 14000 series [1], [2] and [3].

Protection of the environment is a key political issue in Europe and elsewhere. For TC 286 this is covered

in CEN/TS 16765 [4] LPG equipment and accessories - Environmental considerations for CEN/TC 286

standards, and this Technical Specification should be read in conjunction with this document. The

Technical Specification provides guidance on the environmental aspects to be considered regarding

equipment and accessories produced for the LPG industry and the following is addressed:

a) design;
b) manufacture;
c) packaging;
d) use and operation; and
e) disposal.

It has been assumed in the drafting of this document that the execution of its provisions is entrusted to

appropriately qualified and experienced people.
All pressures are gauge pressures unless otherwise stated.

NOTE This document requires measurement of material properties, dimensions and pressures. All such

measurements are subject to a degree of uncertainty due to tolerances in measuring equipment, etc. It may be

beneficial to refer to the leaflet “measurement uncertainty leaflet” SP INFO 2000 27 [5].

---------------------- Page: 7 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
1 Scope

This document specifies the design, testing and inspection requirements for pressure relief valve

isolating devices, valve manifolds, vent pipes and system assemblies which are, where necessary, used

with pressure relief valves for use in static pressure vessels for Liquefied Petroleum Gas (LPG) service.

This document addresses both prototype testing and production testing of isolating devices and PRV

manifolds.
Pressure relief valves for LPG pressure vessels are specified in EN 14129:2014.
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 549:2019, Rubber materials for seals and diaphragms for gas appliances and gas equipment

EN 751-1:1996, Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases

and hot water - Part 1: Anaerobic jointing compounds

EN 751-2:1996, Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases

and hot water - Part 2: Non-hardening jointing compounds

EN 751-3:1996, Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases

and hot water - Part 3: Unsintered PTFE tapes

EN 1092-1:2018, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN

designated - Part 1: Steel flanges
EN 1563:2018, Founding - Spheroidal graphite cast irons
EN 10204:2004, Metallic products - Types of inspection documents
EN 12164:2016, Copper and copper alloys - Rod for free machining purposes
EN 12165:2016, Copper and copper alloys - Wrought and unwrought forging stock
EN 12420:2014, Copper and copper alloys - Forgings

EN 12516-1:2014+A1:2018, Industrial valves - Shell design strength - Part 1: Tabulation method for steel

valve shells

EN 12516-4:2014+A1:2018, Industrial valves - Shell design strength - Part 4: Calculation method for valve

shells manufactured in metallic materials other than steel
EN 13480-3:2017 , Metallic industrial piping - Part 3: Design and calculation
EN 13445-2:2014 , Unfired pressure vessels - Part 2: Materials
1) As impacted by EN 13480-3:2017/A2:2020 and EN 13480-3:2017/A3:2020.

2) As impacted by EN 13445-2:2014/A1:2016, EN 13445-2:2014/A2:2018 and EN 13445-2:2014/A3:2018.

---------------------- Page: 8 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)

EN 13906-1:2013, Cylindrical helical springs made from round wire and bar - Calculation and design - Part

1 : Compression springs

EN 14129:2014, LPG Equipment and accessories - Pressure relief valves for LPG pressure vessels

ISO 6957:1988, Copper alloys - Ammonia test for stress corrosion resistance
ASME B1.20.1:2013, Pipe threads, general purpose (inch)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
liquefied petroleum gas
LPG

low pressure liquefied gas composed of one or more light hydrocarbons which are assigned to UN 1011,

UN 1075, UN 1965, UN 1969 or UN 1978 only and which consists mainly of propane, propene, butane,

butane isomers, butene with traces of other hydrocarbon gases
3.2
pressure vessel

assembly of the pressure envelope (including the openings and their closures) and non-pressure-

retaining parts attached directly to it
3.3
pressure relief valve
PRV

self-closing valve which automatically, without the assistance of any energy other than that of the vapour

concerned, discharges vapour at a predetermined pressure, and operates with a pop action

Note 1 to entry: This is known as a “safety valve” in ADR.
3.4
pressure relief valve system
PRV system

pressure relief valve(s) for use on the pressure vessel complete with isolating device or PRV manifold,

and vent pipe where appropriate
3.5
pressure relief valve isolating device

device fitted between the storage tank and the external pressure relief valve, which permits the

replacement of the pressure relief valve without de-pressuring the pressure vessel

3.6
coefficient of discharge

ratio of the actual measured flow capacity divided by the calculated theoretical capacity for the same fluid

at the same operating conditions
---------------------- Page: 9 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
3.7
pressure relief valve manifold
PRV manifold

device fitted to a storage vessel permitting two or more pressure relief valves to be fitted only one of

which can be isolated at a time, which permits replacement of the isolated pressure relief valve without

depressurizing the vessel
3.8
discharge capacity

capacity at the flow rating pressure of a pressure relief valve expressed in cubic metres per minute of free

air at STP
3.9
vent pipe

open-ended pipe, fitted with a protection cap and attached to the pressure relief valve outlet, to direct

discharged fluid away from the protected pressure vessel surface
3.10
design signal flow

limited flow of LPG intended to equalise pressures so that a replacement PRV can be properly fitted to an

isolating device; indicate the effectiveness of the internal shut off in an isolating device before the PRV is

completely removed; and produce an acoustic signal
3.11
Standard Temperature and Pressure
STP
15,6 °C (288,7 K), 1,013 bar absolute (0,1013 MPa absolute)
3.12
flow rating pressure
inlet pressure at which the discharge capacity is measured
3.13
lift
actual travel of the sealing disc away from the closed position
3.14
sealing element

non-metallic resilient component which effects a seal by contact with the valve seat

3.15
valve seat

normally raised area of the pressure relief valve body on to which the sealing element effects a seal

3.16
maximum allowable pressure
maximum pressure for which the equipment is designed
Note 1 to entry: All pressures are gauge pressures unless otherwise stated.
---------------------- Page: 10 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
3.17
nominal diameter

numerical designation of the size of a component, which is a convenient round number, approximately

equal to the manufacturing dimensions in millimetres (mm)
3.18
external leak tightness
resistance to leakage through the fitting to or from the atmosphere
4 Operating conditions
4.1 Equipment designed in accordance with this document shall be suitable for:
— minimum operating temperature of −20 °C;
— maximum operating temperature of 65 °C;
— maximum allowable pressure of 25 bar; and
— minimum pressure of 50 mbar absolute.

4.2 For some parts of Europe and certain applications, temperatures lower than – 20 °C can be

encountered. For these conditions, a temperature rating of – 40 °C shall apply.

NOTE 1 In service, temperatures below this can be encountered during short periods, for example, during

discharge.

NOTE 2 Vacuum conditions on the isolating device or PRV manifold, arising from butane at low temperature or

evacuation of the pressure vessel can expose the valve or fitting to a vacuum of 50 mbar absolute.

5 Materials
5.1 General

5.1.1 All materials in contact with LPG shall be physically and chemically compatible with LPG under

all normal operating conditions for which the device is intended to be used.

5.1.2 Material for components shall be selected for adequate strength in service. The material shall

resist atmospheric corrosion, brass dezincification, stress corrosion, impact and material failure. Where

stress corrosion could be present in a material, stress relieving heat treatment shall be carried out where

necessary.

5.1.3 The components exposed to atmosphere shall be manufactured from corrosion resistant

materials or suitably protected against corrosion.

NOTE Alternative materials to those listed in 5.2 are not precluded, providing they comply with a standard or

specification that ensures control of chemical and physical properties, and quality appropriate to the end use.

5.2 Metallic materials

5.2.1 Equipment shall be made from steel, stainless steel, copper alloys or other suitable materials.

---------------------- Page: 11 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)

5.2.2 Shell materials shall be selected in accordance with EN 12516-1:2014+A1:2018,

EN 12516-4:2014+A1:2018 or EN 13445-2:2014 .
5.2.3 Materials for steel flanges shall be in accordance with EN 1092-1:2018.

5.2.4 Components made from stainless steel shall contain not less than 16 % chromium, and not less

than 7 % nickel. Springs shall be manufactured from stainless steel wire and shall contain not less than

16 % chromium and not less than 6 % nickel.

5.2.5 Hot stamped brass shall be non-porous and shall be suitable for machining or other processes.

Leaded brass shall be CW614N or CW617N in accordance with EN 12420:2014, EN 12164:2016 or

EN 12165:2016. Sand-cast brass shall not be used. Cold drawn brass rods shall only be used for machining

after adequate testing for internal cracking, porosity or other inclusions and shall be heat treated if

required. Components produced from stamping brass shall not exhibit cold shuts, also known as folds, or

surface defects. Components manufactured from hot stamped brass, drawn brass or machined from brass

rod, shall be capable of withstanding, without cracking, the stress-cracking test.

5.2.6 Components manufactured from hot stamped brass or contents gauge bodies made of drawn

brass or machined from brass rod shall be capable of withstanding, without cracking, the stress-cracking

test in accordance with 7.9.

5.2.7 Spheroidal graphite cast iron shall comply with EN 1563:2018, with an elongation at fracture of

more than 18 %. Other ductile irons or cast irons shall not be used. Castings shall be free from inclusions

and surface defects, which could adversely affect the strength, leak tightness or performance of the

device.
NOTE For guidance on the choice of metallic materials, see EN ISO 11114-1 [7].
5.3 Non-metallic components

All non-metallic materials in contact with LPG shall not distort, harden or adhere to the body or seat face

to such an extent as to impair the function of the device.

All rubber materials shall also comply with the requirements of EN 549:2019. The ozone test in

EN 549:2019 shall only be carried out where gaskets/seals are exposed to the atmosphere.

NOTE For guidance on the choice of non-metallic materials, see EN ISO 11114-2 [8].

5.4 Lubricants, sealants, and adhesives

Where used on threads and seals; lubricants, sealants, and adhesives shall be compatible with LPG and

shall not interfere with the operation of the valve or fitting.
Sealants shall comply with EN 751-1:1996, EN 751-2:1996 or EN 751-3:1996.
5.5 Inspection Documents

The main metallic pressure-bearing parts shall be provided with material manufacturers’ certificates

conforming to EN 10204:2004, certificate type 3.1.

Springs and other metallic parts shall have certificates conforming to EN 10204:2004 certificate type 2.2.

Non-metallic parts shall be provided with certificates confirming their conformance with the

specification.
---------------------- Page: 12 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
6 Design
6.1 Introduction

6.1.1 This section identifies essential requirements for the design of ancillary equipment.

6.1.2 The design shall allow the equipment to operate with the flow characteristics as identified in 7.8.

6.1.3 Equipment components shall be designed with adequate strength and clearances to ensure

correct operation in service.
6.1.4 The design should take account of the following:
— minimizing the use of raw materials;

— minimizing the environmental impact of in-service maintenance and end of life disposal; and

— efficient packaging of the finished product.
6.2 Pressure relief valve isolating devices
6.2.1 General

Pressure relief valves intended for use with these isolating devices shall be in accordance with

EN 14129:2014.

If interchangeability of pressure relief valves of diverse manufacturers is required, the requirements of

6.2.6 shall be fulfilled.
6.2.2 Actuation

Isolating devices shall only be actuated by the fitting or removal of the pressure relief valve. The isolating

mechanism shall be closed by a spring.
The seal should preferably be metal to metal.
6.2.3 Indication of closure

Isolating devices shall have positive means to determine that closure has occurred when the PRV has

been removed. This shall be achieved by:

— the use of two tell-tale holes in the pressure relief valve. When one complete hole is visible above the

bonded seal, the isolating device shall close within one further revolution. (The valve should be

closed within five revolutions when removing a fully engaged relief valve from an isolating device).

When the isolating device is closed there shall be three full revolutions remaining before

disengagement. The use of visible marking (e.g. machined groove) may be used on a thermal

expansion valve which shall be visible when three full turns of engagement remain;

— a noticeable audible change in the release of gas which shall have taken place when removing the

pressure relief valve indicating closure of the isolating device while a minimum of three threads

remain engaged.

When the isolating device is closed the residual flow shall not exceed 600 l/h at 1 bar differential and

STP.

The residual flow through a port of a PRV manifold, with a PRV removed, shall not exceed 2,5 l/h at 1 bar

differential and STP.
---------------------- Page: 13 ----------------------
oSIST prEN 14071:2021
prEN 14071:2021 (E)
6.2.4 Guiding arrangements
The design shall incorporate guiding arrangements of the isolating mechani
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.