Essential Safety Requirements
"ESRs"
A Comparison with BS 5500 and ASME VIII
Div 1
The European
Pressure Equipment Directive 97/23/EC, (PED), places full
responsibility
upon the manufacturer of pressure equipment to comply with
the provisions
of the Directive.
On completion
of all design, manufacturing, inspection and testing procedures,
and after
verification of conformity, the manufacturer can make a Declaration
of Conformity
with the PED.
The
manufacturer can then affix the CE marking which ensures that the equipment
will have
freedom of movement within the European Community.
An important
requirement is that the manufacturer must comply with all the
Essential
Safety Requirements, (ESRs), in Annex 1 of the PED which are relevant
to the
equipment for which he makes the Declaration of Conformity.
The following
table provides a summary of all the ESRs and shows, by reference
to the
relevant clauses in BS 5500 and ASME VIII Div 1, where it is considered
that these
codes satisfy the ESRs.
Numbers in
brackets ( ) refer to notes, see end of table.
Sub PED Essential Safety Requirement ³ASME VIII EN
Section ³ Div1 5500
1 GENERAL ³
======== ³
1.1 Equipment must be designed, manufactured and ³
checked, and installed in such a
way as to ³ (6) (1)
ensure put into service in
accordance with the ³
manufacturers instructions. ³
³
1.2 Manufacturer must apply the principles set out ³
below in the following order: ³
- eliminate or reduce hazards as far as ³
is reasonably
practicable, ³ (6) (1)
- apply appropriate protection measures ³
against hazards ³
- inform users of residual hazards ³
³
1.3 The pressure equipment designed to prevent ³ (6) (1)
danger from misuse or, adequate
warning given. ³
³
Page 2 of 11
2 DESIGN ³
====== ³
2.1 The pressure equipment must be properly ³
designed to be safe throughout its
intended ³
life. ³ U-2 3.1
Design must incorporate
appropriate safety ³
coefficients. ³
³
2.2.1 To be designed for loadings appropriate ³ UG-22 3.2.1
use. ³
2.2.2 Design for adequate strength based on: ³
- a calculation method and supplemented if ³
necessary by an experimental
design method. ³ 3.2.2
- an experimental Design method without ³ U-2
calculation, when the product of
the maximum ³ 3.2.2(3)
allowable pressure PS and the
volume V is les ³
than 6 000 bar x Liters. ³
³
2.2.3(a) The allowable stresses for
pressure equipment ³ UG-23
must be limited having regard to
reasonably ³
foreseeable failure modes, safety
factors must ³
be applied to. ³
Requirements may be met by
applying one of the ³ (8)*
following methods ³
- Design by formula ³ Section 3
- Design by analysis ³ Annex A
- Design by fracture mechanics; ³
U-2(g) Annex U
* Design by analysis or fracture mechanics ³
only permitted where formulas
do not exist. ³
³
2.2.3(b) Appropriate design calculations
must be used to ³
establish the resistance of the
pressure ³
equipment concerned. ³
In particular: ³
- the calculation pressures must not be less ³ UG-21 3.2.3
than the maximum allowable
pressures and ³
take into account static head
and dynamic ³
fluid pressures and the
decomposition of ³
unstable fluids. ³
Page 3 of 11
- the calculation temperature must allow for ³ UG-20 3.2.4
appropriate safety margin ³
- the Design must take appropriate account ³UG-22 3.2.4/3.2.5
of all possible combinations of
temperature ³
and pressure which might arise
under ³
reasonably foreseeable
operating ³
conditions. ³
- maximum stresses and peak stress kept ³UG-23 3.1.1
within the safe limits ³
- the calculation for pressure containment ³UG-23 Annex K
must utilize the values
appropriate to the ³
properties of the material,
based on ³
documented data. ³
- appropriate joint factors must be applied ³UG-27 (1)
- the Design must take appropriate account ³UG-25 3.2.4/3.3
of all reasonably foreseeable
degradation ³ Annex C
mechanisms. ³
³
2.2.3(c) calculated allow for adequate
structural ³ (7) (2)
stability taking into account the
risks from ³
transport and handling ³
³
2.2.4 Design by experimental method must be ³
validated by an appropriate test
programme ³
on a sample representative of the
equipment ³ 3.2.2 &
the equipment. ³UG-101 5.8.6
Test programme must be clearly
defined and ³ (3)
must include a pressure strength
test. ³
2.3 Provisions to Ensure Safe Handling and ³
Operation Method of operation
specified for ³ (8)
pressure equipment must be such as
to preclude ³
any reasonably foreseable risk in
operation ³ UG-36
of the equipment. ³
Particular attention must be paid
to: ³
- closures and openings, ³UG-135(b)
- dangerous discharge of pressure
relief ³ (1)
blow-off, ³
- devices to prevent physical
access whilst ³ (8)
pressure or a vacuum exists ³UG-35(b)
Page 4 of 11
- surface temperature taking
into ³ (7)
consideration the intended
use, ³
- decomposition of unstable
fluids ³ (7)
Pressure equipment fitted with an
access ³
door must be equipped with an
automatic ³
or manual device enabling the user
easily to ³ (7)
ascertain that opening it will not
present ³
any hazard. ³
Where the opening can be operated
quickly ³UG-35(b)
equipment must be fitted with a
device to ³
prevent it being opened whenever
the pressure ³
or temperature of the fluid presents a
hazard ³
³
2.4(a) Pressure equipment must be designed and ³
constructed so that all necessary
examinations ³
to ensure safety can be carried
out; ³UG-46 3.12(3)
carried out; ³
³
2.4(b) Means of determining the internal condition ³UG-46 3.12
of the equipment must be
available ³
³
2.5 Means must be provided for the draining and ³
venting of pressure equipment
where necessary: ³UG-25(b) (1)
- to avoid harmful effects such as
water hammer ³
vacuum collapse, corrosion and
uncontrolled ³ (7)
chemical reactions. ³
- to permit cleaning, inspection
and ³
UG-46
maintenance in a safe
manner. ³
³
2.6 Adequate allowance or protection against ³ UG-25 3.3
corrosion or other chemical attack
must ³
be provided. ³
³
2.7 Where erosion or abrasion may arise, adequate ³ (8) 3.3.4(3)
must be taken to: ³
- minimize that effect by
appropriate Design ³UG-26
EX/EG replacement of parts
instructions. ³
Page 5 of 11
2.8 Assemblies must be so designed that: ³
- the components to be assembled
together ³ (7) (2)
are suitable and reliable for
their duty ³
- all the components are properly
integrated ³
and assembled in an appropriate
manner. ³
³
2.9 Equipment must be so designed and provided with ³
accessories or provision made for
their fitting ³
as to ensure safe filling and
discharge in ³
particular with respect to hazards
such as on ³
filling: ³
- overfilling or
overpressurizatio ³
(6) (1)
- instability of the pressure
equipment; ³
- on discharge the uncontrolled
release of the ³
pressurised fluid; ³
- on filling or discharge; unsafe
connection ³
and disconnection ³
³
2.10 Where the allowable limits could be exceeded, ³
the pressure equipment must be
fitted with, ³
or provision made for the fitting
of suitable ³
protective devices based on the
particular ³UG-125 3.13
characteristics of the equipment
or assembly. ³
³
2.11.1 Safety accessories must: ³
- be designed and constructed as
to be reliable ³UG-126 3.13.1
and suitable for their intended
duty, ³
- be independent of other
function, ³UG-127 3.13.1
- comply with appropriate Design
principles ³ 3.13.1
in order to obtain suitable and
reliable ³
protection. ³
³
2.11.2 Pressure Limiting Devices ³
Must be so designed that the
pressure will ³UG-131 3.13.2
not permanently exceed the maximum
allowable ³
pressure ³
³
2.11.3 Temperature Monitoring Devices ³(6) (1)
Must have an adequate response
time. ³
³
2.12 Where necessary, pressure equipment must ³UG-125 1.1.5(3)
designed and, where appropriate,
fitted ³U 2
& 3
accessories, to meet
danger-limitation ³
requirements in the event of
external fire. ³
Page 6 of 11
3 MANUFACTURING ³
============= ³
3.1 The manufacture must ensure the competent ³
execution of the provisions set
out at the ³
design stage by applying the
appropriate ³
techniques and relevant
procedures, especially ³
with a view to the aspects set out
below. ³
³
3.1.1 Preparation of the component parts must not ³
give rise to defects or cracks or
changes ³
in the mechanical characteristics
likely to ³UG-76 4.2
be detrimental to the safety of
the pressure ³
equipment. ³
³
3.1.2 Permanent joints and adjacent zones must be ³(7)UW-35 5.6 (3)
free of any surface or internal
defects ³
detrimental to the safety of the
equipment. ³
The properties of permanent joints
must meet ³Section IX 4.3
the minimum properties specified
for the ³
materials to be joined unless
relevant property ³
values are specifically taken into
account in ³
design. ³
³
Permanent joining of components
which ³ UW-28 4.3
contribute to the pressure
resistance of ³
equipment and components which are
directly ³ UW-29
attached to them must be carried
out by ³
suitably qualified personnel
according to ³
suitable operating
procedures. ³
³
For pressure equipment in
categories II, ³ (7) 4.3
operating procedures and personnel must
be ³
approved by a competent third
party which, ³
at the manufacturers discretion,
may be:
- a notified body ³
- a third-party organisation
recognised by a ³
Member State as provided for in
Article 13. ³
³
3.1.3 Non-destructive tests of permanent joint must ³ UW-51(a)2
be carried out by suitable
qualified personnel. ³ App6 5.6.1
For pressure equipment in
categories
III
and IV ³ App8
the personnel must be approved by
a third-party³
organisation.
Page 7 of 11 ³
3.1.4 Where the manufacturing process will change the ³ UW-40 4.4
material properties to impair the
safety of ³
the pressure equipment, suitable
heat treatment ³
must be applied at the appropriate
stage of ³
manufacture. ³
³
3.1.5 Procedures must be established and maintained ³ UG-77 4.1.2
for identifying the material
making up the ³
components. ³
³
3.2 Pressure equipment must be subjected to ³
final assessment as described
below. ³
³
3.2.1 Equipment must undergo a final inspection ³ UG-97 5.1(3)
to asses visually and by
examination of the ³
accompanying documents, compliance
with the ³
requirements of the
Directive. ³
The final inspection must be
carried out ³
internally and externally on every
part of ³
the equipment, where appropriate
in the ³
course of manufacture. ³
³
3.2.2 Final assessment must include a test for ³ UG-99 5.8 (3)
the pressure containment aspect,
which will ³
normally take the form of a
hydrostatic ³
pressure test. ³
For category 1 series-produced
pressure ³
UG-100 Annex V
test may be performed on a
statistical ³ (3)
basis. ³
Where the hydrostatic pressure
test is ³
(7) 5.8.4
harmful or impractical, other
tests of a ³
recognised value may be carried
out. ³
³
3.2.3 For assemblies, the final assessment must ³
also include a check of the safety
devices ³ UG-125* (1)
intended to check full compliance
with the ³
requirements referred to in
2.10. ³
* Safety devices, whilst in the ASME need ³
not be fitted by the vessel
manufacturer. ³
³
3.3 In addition to the CE marking the following ³
information must be provided: ³
³
Page 8 of 11
3.3(a) the name and address of the manufacturer and, ³
where appropriate, of his
authorised represent ³ (7) 1.4.4
within the Community. ³ 5.8.9 (3)
- the year of manufacture, ³
- identification of the pressure
equipment ³
- essential maximum/minimum
allowable limits ³
³
3.3(b) depending upon the type of equipment, further ³
information necessary for safe
installation, ³ (7) (2)
operation or use and, where
applicable, ³
maintenance and periodic
inspection. ³
³
3.3(c) where necessary, warnings fixed to the ³
equipment drawing attention to
misuse which ³
experience has shown might
occur ³ (7) (2)
occur. ³
3.4 Operating Instructions ³ (1)
4 MATERIALS
=========
Materials used for the manufacture
of ³ UG-4 2.1
pressure equipment must be
suitable for such ³
application during the
scheduled ³
lifetime unless replacement is
foreseen. ³
4.1 Materials for pressurised parts must: ³
4.1(a) have appropriate properties for all operating ³ UG-4 2.2(3)
and be sufficiently ductile and
tough. ³ UG-84
care should be exercised, in
particular, ³
in selecting materials and weld
pocedures ³
in order to prevent brittle-type
fracture; ³
4.1(b) be sufficiently chemically resistant to fluid ³ UHA-6 3.3.1
contained in the pressure
equipment; ³ (8)
4.1(c) not be significantly affected by ageing; ³ (2)
4.1(d) be suitable for the intended processing ³ (7) (2)
procedures.
Page 9 of 11
4.1(e) be selected in order to avoid significant ³ UG-18 (2)
undesirable effects when the
various materials ³
are put together.
4.2(a) The pressure equipment manufacturer must define³ (4) (4)
in an appropriate manner the
values necessary
for the design
calculationsreferred to in 2.2.3
AND
4.2(b) the manufacturer must provide in his technical ³ (7) 2.1.2
documentation elements relating to
compliance ³ (3)
compliance with the materials
specifications of
the Directive in one of the
following forms:
- by using Materials which comply
with
harmonized standards
- by using Materials covered by A
European
approval of pressure equipment
materials
- by a particular material
appraisal;
4.2(c) for equipment in categories
III
and IV, ³ (6) (2)
particular appraisal as referred
to in the 3rd ³
indent of (b) must be performed by
the notified ³
body in charge of conformity
assessment ³
procedures for the pressure
equipment. ³
³
4.3 Manufacturer must take appropriate measures ³ UG-93
to ensure that the material used
conforms with ³
the required specification. ³
In particular, documentation
prepared by the ³
material manufacturer affirming
compliance with ³
a specification must be obtained for
all
materials.
For equipment in categories II,
III
and IV ³ UG-93 (2)
this must take the form of a
certificate of
specific product control.
Where material manufacture has an
appropriate ³ (6)
quality assurance system,
certified by a
competent body established within
the Community
and having undergone a specific
assessment for
materials, certificates issued by
the
manufacturer are presumed to
certify conformity
with the relevant requirements of
this section.
Page 10 of 11
6 PIPING ³ (6) (1)
====== ³ goto
³ ASME 31.3B
³
7 SEPCIFIC QUANTITATIVE
REQUIREMENTS ³
FOR CERTAIN PRESSURE
EQUIPMENT. ³
================================= ³
7.1 Allowable stresses ³ Annex K (3)
7.2 Joint coefficients ³ (1)
³
7.3 Pressure limiting devices, particularly for ³ Annex J
pressure vessels ³
The momentary pressure surge must
keep to 10% ³
of the allowable pressure. ³
³
7.4 For pressure vessels, the
hydrostatic test ³ UG-99 5.8(3)
must be no less than that
corresponding to ³
the maximum loading to which the
pressure ³
equipment may be subject in
service, taking ³
into account its maximum allowable
pressure ³
at its maximum allowable
temperature, ³
multiplied by the coefficient
1.25 ³
or ³
the maximum allowable pressure
multiplied ³
by the coefficient 1.43 ³
whichever is the
greater. ³
³
7.5 Unless other values are required in accordance ³ (6) (2)
other criteria that must be taken
into account, ³
a steel is considered as
sufficiently ductile ³
to satisfy 4.1(a) if, in a tensile
test carried ³
out by a standard procedure, its
elongation ³
after rupture is no less than 14%
and its ³
bending rupture energy measured on
an ISO V ³
test-piece is no less than 27 J,
at a ³
temperature not greater than 20C
but not higher ³
that the lowest scheduled
operating procedure. ³
³
Page 11
of 11
NOTES: ³
====== ³
(1) Outside scope of current BS 5500. ³
(2) Requirements not given in BS 5500. ³
Consideration needed to inclusion? ³
(3) Referencclause? ³
(4) Uncertain as to meaning of
ESR
³
(6) Outside the scope of ASME ³
(7) Requirement not addressed in ASME ³
(8) Requirement partly addressed in ASME ³
³
(10) EN 13445
harmonization and BS/EN 5500 ³
³
