EN ISO 13705:2012

SLOVENSKI STANDARD
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Petroleum, petrochemical and natural gas industries - Fired heaters for general refinery
service (ISO 13705:2012)
Erdöl-, petrochemische und Erdgasindustrie - Befeuerte Erhitzer für den allgemeinen
Einsatz in Raffinerien (ISO 13705:2012)
Industries du pétrole, de la pétrochimie et du gaz naturel - Réchauffeurs à brûleurs pour
usage général dans les raffineries (ISO 13705:2012)
Ta slovenski standard je istoveten z: EN ISO 13705:2012
ICS:
75.180.20 Predelovalna oprema Processing equipment
97.100.01 Grelniki na splošno Heating appliances in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 13705
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2012
ICS 75.180.20 Supersedes EN ISO 13705:2006
English Version
Petroleum, petrochemical and natural gas industries - Fired
heaters for general refinery service (ISO 13705:2012)
Industries du pétrole, de la pétrochimie et du gaz naturel - Erdöl-, petrochemische und Erdgasindustrie - Befeuerte
Réchauffeurs à brûleurs pour usage général dans les Erhitzer für den allgemeinen Einsatz in Raffinerien (ISO
raffineries (ISO 13705:2012) 13705:2012)
This European Standard was approved by CEN on 14 December 2012.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, 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.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13705:2012: E
worldwide for CEN national Members.

Contents Page
Foreword . 3

Foreword
This document (EN ISO 13705:2012) has been prepared by Technical Committee ISO/TC 67 "Materials,
equipment and offshore structures for petroleum, petrochemical and natural gas industries" in collaboration
with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for petroleum,
petrochemical and natural gas industries” the secretariat of which is held by AFNOR.
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 June 2013, and conflicting national standards shall be withdrawn at
the latest by June 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 13705:2006.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, 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 the United Kingdom.
Endorsement notice
The text of ISO 13705:2012 has been approved by CEN as a EN ISO 13705:2012 without any modification.

INTERNATIONAL ISO
STANDARD 13705
Third edition
2012-12-15
Petroleum, petrochemical and natural gas
industries — Fired heaters for general
refinery service
Industries du pétrole, de la pétrochimie et du gaz naturel —
Réchauffeurs à brûleurs pour usage général dans les raffineries

Reference number
ISO 13705:2012(E)
©
ISO 2012
ISO 13705:2012(E)
©  ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

ISO 13705:2012(E)
Contents Page
Foreword .v
Introduction.vi
1 Scope.1
2 Normative references.1
3 Terms, definitions, abbreviated terms and symbols .4
3.1 Terms and definitions .4
3.2 Abbreviated terms and symbols.11
4 General .12
4.1 Pressure design code .12
4.2 Regulations .12
4.3 Heater nomenclature.12
5 Proposals .16
5.1 Purchaser's responsibilities.16
5.2 Vendor's responsibilities.16
5.3 Documentation .16
5.4 Final reports.18
6 Design considerations.18
6.1 Process design .18
6.2 Combustion design .19
6.3 Mechanical design.19
7 Tubes .20
7.1 General .20
7.2 Extended surface.21
7.3 Materials .22
8 Headers.22
8.1 General .22
8.2 Plug headers .23
8.3 Return bends .24
8.4 Materials .24
9 Piping, terminals and manifolds .25
9.1 General .25
9.2 Allowable movement and loads.26
9.3 Materials .28
10 Tube suppports .28
10.1 General .28
10.2 Loads and allowable stress.29
10.3 Materials .30
11 Refractories and insulation .31
11.1 General .31
11.2 Brick and tile construction .32
11.3 Castable construction.33
11.4 Ceramic-fibre construction.33
11.5 Multi-component lining construction .35
11.6 Materials .35
12 Structures and appurtenances .36
12.1 General .36
ISO 13705:2012(E)
12.2 Structures .36
12.3 Header boxes, doors and ports.37
12.4 Ladders, platforms and stairways.37
12.5 Materials .38
13 Stacks, ducts and breeching.39
13.1 General.39
13.2 Design considerations .39
13.3 Design methods.41
13.4 Static design.41
13.5 Wind-induced vibration design .42
13.6 Materials .43
14 Burners and auxiliary equipment.43
14.1 Burners .43
14.2 Sootblowers .48
14.3 Fans and drivers .48
14.4 Dampers and damper controls for stacks and ducts.48
15 Instrument and auxiliary connections.49
15.1 Flue gas and air.49
15.2 Process fluid temperature .50
15.3 Auxiliary connections .50
15.4 Tube-skin thermocouples .51
15.5 Access to connections.51
16 Shop fabrication and field erection.51
16.1 General.51
16.2 Structural-steel fabrication.52
16.3 Coil fabrication.53
16.4 Painting and galvanizing.54
16.5 Refractories and insulation .54
16.6 Preparation for shipment .55
16.7 Field erection.56
17 Inspection, examination and testing.56
17.1 General.56
17.2 Weld examination .57
17.3 Castings examination.57
17.4 Examination of other components.58
17.5 Testing .59
Annex A (informative) Equipment data sheets.61
Annex B (informative) Purchaser's checklist .90
Annex C (informative) Proposed shop-assembly conditions.94
Annex D (normative) Stress curves for use in the design of tube-support elements .96
Annex E (normative) Centrifugal fans for fired-heater systems.111
Annex F (normative) Air preheat systems for fired process heaters .128
Annex G (informative) Measurement of efficiency of fired process heaters.186
Annex H (informative) Stack design.254
Annex I (informative) Measurement of noise from fired-process heaters.264
Bibliography .300

iv © ISO 2012 – All rights reserved

ISO 13705:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 13705 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 6, Processing equipment and
systems.
This third edition cancels and replaces the second edition (ISO 13705:2006), which has been technically
revised.
ISO 13705:2012(E)
Introduction
Users of this International Standard should be aware that further or differing requirements may be needed for
individual applications. This International Standard is not intended to inhibit a vendor from offering, or the
purchaser from accepting, alternative equipment or engineering solutions for the individual application. This
may be particularly applicable where there is innovative or developing technology. Where an alternative is
offered, the vendor should identify any variations from this International Standard and provide details.
In International Standards, the SI system of units is used. Where practical in this International Standard, US
Customary (USC) units are included in brackets for information.
A bullet (●) at the beginning of a clause or subclause indicates that either a decision is required or further
information is to be provided by the purchaser. This information should be indicated on data sheets (see
examples in Annex A) or stated in the enquiry or purchase order. Decisions should be indicated on a checklist
(see example in Annex B).
vi © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 13705:2012(E)

Petroleum, petrochemical and natural gas industries — Fired
heaters for general refinery service
1 Scope
This International Standard specifies requirements and gives recommendations for the design, materials,
fabrication, inspection, testing, preparation for shipment, and erection of fired heaters, air heaters (APHs),
fans and burners for general refinery service.
This International Standard is not intended to apply to the design of steam reformers or pyrolysis furnaces.
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.
ISO 1461, Hot dip galvanized coatings on fabricated iron and steel articles — Specifications and test methods
ISO 1940-1:2003, Mechanical vibration — Balance quality requirements for rotors in a constant (rigid) state —
Part 1: Specification and verification of balance tolerances
ISO 8501-1, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel
substrates and of steel substrates after overall removal of previous coatings
ISO 10684, Fasteners — Hot dip galvanized coatings
ISO 13704, Petroleum, petrochemical and natural gas industries — Calculation of heater-tube thickness in
petroleum refineries
ISO 15649, Petroleum and natural gas industries — Piping
IEC 60079 (all parts), Electrical apparatus for explosive gas atmospheres
EN 10025-2:2004 , Hot rolled products of structural steels — Part 2: Technical delivery conditions for non-
alloy structural steels
ABMA Standard 9 , Load Ratings and Fatigue Life for Ball Bearings
AMCA 210 , Laboratory Methods of Testing Fans for Aerodynamic Performance Rating
AMCA 801:2001, Industrial Process/Power Generation Fans — Specifications and Guidelines

1 European Committee for Standardization (CEN), Rue de Stassart 36, B-1050 Brussels, Belgium.
2 American Bearing Manufacturers Association, 2025 M. Street, NW, Suite 800, Washington, DC 20036, USA.
3 Air Movement and Control Association, 30 West University Drive, Arlington Heights, IL 60004, USA.
ISO 13705:2012(E)
ASME B 17.1 , Keys and Keyseats
ASME Boiler and Pressure Vessel Code, Section VIII, Pressure Vessels
ASTM A 36 , Standard Specification for Carbon Structural Steel
ASTM A 53, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
ASTM A 105, Standard Specification for Carbon Steel Forgings for Piping Applications
ASTM A 106, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service
ASTM A 123, Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
ASTM A 143, Standard Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural
Steel Products and Procedure for Detecting Embrittlement
ASTM A 153, Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware
ASTM A 181, Standard Specification for Carbon Steel Forgings, for General-Purpose Piping
ASTM A 182, Standard Specification for Forged or Rolled Alloy and Stainless-Steel Pipe Flanges, Forged
Fittings, and Valves and Parts for High-Temperature Service
ASTM A 192, Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service
ASTM A 193, Standard Specification for Alloy-Steel and Stainless Steel Bolting for High-Temperature or High-
Pressure Service and Other Special Purpose Applications
ASTM A 194, Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure or High-
Temperature Service, or Both
ASTM A 209, Standard Specification for Seamless Carbon-Molybdenum Alloy-Steel Boiler and Superheater Tubes
ASTM A 210, Standard Specification for Seamless Medium-Carbon Steel Boiler and Superheater Tubes
ASTM A 213, Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and
Heat-Exchanger Tubes
ASTM A 216, Standard Specification for Steel Castings, Carbon, Suitable for Fusion Welding, for High-
Temperature Service
ASTM A 217, Standard Specification for Steel Castings, Martensitic Stainless and Alloy, for Pressure-
Containing Parts, Suitable for High-Temperature Service
ASTM A 234, Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate
and High Temperature Service
ASTM A 240, Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and
Strip for Pressure Vessels and for General Applications
ASTM A 242, Standard Specification for High-Strength Low-Alloy Structural Steel
ASTM A 283, Standard Specification for Low and Intermediate Tensile Strength Carbon Steel Plates
ASTM A 297, Standard Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat
Resistant, for General Application
ASTM A 307, Standard Specification for Carbon Steel Bolts and Studs, 60 000 PSI Tensile Strength

4 American Society of Mechanical Engineers, 3 Park Avenue, New York, NY 10017, USA.
5 American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, USA.
2 © ISO 2012 – All rights reserved

ISO 13705:2012(E)
ASTM A 312, Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless
Steel Pipes
ASTM A 320, Standard Specification for Alloy Steel and Stainless Steel Bolting Materials for Low-
Temperature Service
ASTM A 325, Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile
Strength
ASTM A 335, Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
ASTM A 351, Standard Specification for Castings, Austenitic, for Pressure-Containing Parts
ASTM A 376, Standard Specification for Seamless Austenitic Steel Pipe for High-Temperature Central-Station
Service
ASTM A 384, Standard Practice for Safeguarding Against Warpage and Distortion During Hot-Dip Galvanizing
of Steel Assemblies
ASTM A 385, Standard Practice for Providing High-Quality Zinc Coatings (Hot-Dip)
ASTM A 387, Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum
ASTM A 403, Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
ASTM A 447, Standard Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-
Temperature Service
ASTM A 560, Standard Specification for Castings, Chromium-Nickel Alloy
ASTM A 572, Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel
ASTM A 608, Standard Specification for Centrifugally Cast Iron-Chromium-Nickel High-Alloy Tubing for
Pressure Application at High Temperatures
ASTM B 366, Standard Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings
ASTM B 407, Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube
ASTM B 564, Standard Specification for Nickel Alloy Forgings
ASTM B 633, Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
ASTM C 27, Standard Classification of Fireclay and High-Alumina Refractory Brick
ASTM C 155, Standard Classification of Insulating Firebrick
ASTM C 332, Standard Specification for Lightweight Aggregates for Insulating Concrete
ASTM C 401, Standard Classification of Alumina and Alumina-Silicate Castable Refractories
ASTM C 612, Standard Specification for Mineral Fiber Block and Board Thermal Insulation
AWS D 1.1, Structural Welding Code — Steel
AWS D 14.6, Specification for Welding of Rotating Elements of Equipment
NFPA 70 , National Electrical Code
SSPC SP 6/NACE No 3 , Commercial Blast Cleaning

6 American Welding Society, 550 NW Le Jeune Road, Miami, FL 33126, USA.
7 National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269-9101, USA.
8 The Society for Protective Coatings, 40, 24th Street, Pittsburg, PA 15222-4643, USA.
ISO 13705:2012(E)
3 Terms, definitions, abbreviated terms and symbols
For the purposes of this document, the following terms and definitions apply.
NOTE Terms and definitions related to centrifugal fans are given in Annex E.
3.1 Terms and definitions
3.1.1
air heater
air preheater
APH
heat transfer apparatus through which combustion air is passed and heated by a medium of higher
temperature, such as combustion products, steam or other fluid
3.1.2
anchor
tieback
metallic or refractory device that holds the refractory or insulation in place
3.1.3
arch
flat or sloped portion of the heater radiant section opposite the floor
3.1.4
atomizer
device used to reduce a liquid fuel oil to a fine mist, using steam, air or mechanical means
3.1.5
backup layer
refractory layer behind the hot-face layer
3.1.6
balanced-draught heater
heater that uses forced-draught fans to supply combustion air and induced-draught fans to remove flue gases
3.1.7
breeching
heater section where flue gases are collected after the last convection coil for transmission to the stack or the
outlet ductwork
3.1.8
bridgewall
gravity wall
wall that separates two adjacent heater zones
3.1.9
bridgewall temperature
temperature of flue gas leaving the radiant section
3.1.10
burner
device that introduces fuel and air into a heater at the desired velocities, turbulence and concentration to
establish and maintain proper ignition and combustion
NOTE Burners are classified by the type of fuel fired, such as oil, gas, or a combination of gas and oil, which may be
designated as “dual fuel” or “combination”.
4 © ISO 2012 – All rights reserved

ISO 13705:2012(E)
3.1.11
butterfly damper
single-blade damper, which pivots about its centre
3.1.12
casing
metal plate used to enclose the fired heater
3.1.13
castable
insulating concrete poured or gunned in place to form a rigid refractory shape or structure
3.1.14
ceramic fibre
fibrous refractory insulation which can be in the form of refractory ceramic fibre (RCF) or man-made vitreous
fibre (MMVF)
NOTE Applicable forms include bulk, blanket, board, modules, paper, coatings, pumpables and vacuum-formed
shapes.
3.1.15
convection section
portion of the heater in which the heat is transferred to the tubes primarily by convection
3.1.16
corbel
projection from the refractory surface generally used to prevent flue gas from bypassing the tubes of the
convection section if they are on a staggered pitch
3.1.17
corrosion allowance
material thickness added to allow for material loss during the design life of the component
3.1.18
corrosion rate
rate of reduction in the material thickness due to chemical attack from the process fluid or flue gas or both
3.1.19
crossover
interconnecting piping between any two heater-coil sections
3.1.20
damper
device for introducing a variable resistance in order to regulate the flow of flue gas or air
3.1.21
direct-APH
heat exchanger that transfers heat directly between the flue gas and the combustion air
NOTE A regenerative APH uses heated rotating elements and a recuperative design uses stationary tubes, plates or
cast-iron elements to separate the two heating media.
3.1.22
draught
negative pressure (vacuum) of the air and/or flue gas measured at any point in the heater
3.1.23
draught loss
pressure drop (including buoyancy effect) through duct conduits or across tubes and equipment in air and flue
gas systems
ISO 13705:2012(E)
3.1.24
duct
conduit for air or flue gas flow
3.1.25
fuel efficiency
total heat absorbed divided by the total input of heat derived from the combustion of fuel only (lower heating
value basis)
NOTE This definition excludes sensible heat of the fuels and applies to the net amount of heat exported from the unit.
3.1.26
thermal efficiency
total heat absorbed divided by the total input of heat derived from the combustion of fuel plus sensible heats
from air, fuel and any atomizing medium
3.1.27
erosion
reduction in material thickness due to mechanical attack from a fluid
3.1.28
excess air
amount of air above the stoichiometric requirement for complete combustion
NOTE Excess air is expressed as a percentage.
3.1.29
extended surface
heat-transfer surface in the form of fins or studs attached to the heat-absorbing surface
3.1.30
extension ratio
ratio of total outside exposed surface to the outside surface of the bare tube
3.1.31
flue gas
gaseous product of combustion including excess air
3.1.32
forced-draught heater
heater for which combustion air is supplied by a fan or other mechanical means
3.1.33
fouling allowance
factor to allow for a layer of residue that increases the pressure drop
NOTE 1 This residue is usually a build-up of coke or scale on the inner surface of a coil.
NOTE 2 The fouling allowance is used in calculating the fouled pressure drop.
3.1.34
fouling resistance
factor used to calculate the overall heat transfer coefficient
NOTE The inside fouling resistance is used to calculate the maximum metal temperature for design. The external
fouling resistance is used to compensate the loss of performance due to deposits on the external surface of the tubes or
extended surface.
6 © ISO 2012 – All rights reserved

ISO 13705:2012(E)
3.1.35
guillotine
isolation blind
single-blade device used to isolate equipment or heaters
3.1.36
header
return bend
cast or wrought fitting shaped in a 180° bend and used to connect two or more tubes
3.1.37
header box
internally insulated compartment, separated from the flue gas stream, which is used to enclose a number of
headers or manifolds
NOTE Access is afforded by means of hinged doors or removable panels.
3.1.38
heat absorption
total heat absorbed by the coils, excluding any combustion air preheat
3.1.39
average heat flux density
heat absorbed divided by the exposed heating surface of the coil section
NOTE Average flux density for an extended-surface tube is indicated on a bare surface basis with extension ratio
noted.
3.1.40
maximum heat flux density
maximum local rate of heat transfer in the coil section
3.1.41
total heat release
heat liberated from the specified fuel, using the lower heating value of the fuel
3.1.42
volumetric heat release
heat released (net) divided by the net volume of the radiant section, excluding the coils and refractory dividing
walls
3.1.43
higher heating value
gross heating value
total heat obtained from the combustion of a specified fuel at 15 °C (60 °F)
3.1.44
lower heating value
net heating value
higher heating value minus the latent heat of vaporization of the water formed by combustion of hydrogen in
the fuel
3.1.45
hot-face layer
refractory layer exposed to the highest temperatures in a multilayer or multi-component lining
3.1.46
hot-face temperature
temperature of the refractory surface in contact with the flue gas or heated combustion air
ISO 13705:2012(E)
3.1.47
indirect APH
fluid-to-air heat-transfer device
NOTE The heat transfer can be accomplished by using a heat-transfer fluid, process stream or utility stream that has
been heated by the flue gas or other means. A heat pipe APH uses a vaporizing/condensing fluid to transfer heat between
the flue gas and air.
3.1.48
induced-draught heater
heater that uses a fan to remove flue gases and to maintain a negative pressure in the heater to induce
combustion air without a forced-draught fan
3.1.49
interface temperature
calculated temperature between each layer of multilayer or multi-component refractory construction
3.1.50
jump over
interconnecting pipework within a heater coil section
3.1.51
louvre damper
damper consisting of several blades, each of which pivots about its centre and is linked to the other blades for
simultaneous operation
3.1.52
manifold
chamber for the collection and distribution of fluid to or from multiple parallel flow paths
3.1.53
man-made vitreous fibre
MMVF
synthetic amorphous glass insulation fibre, based on a calcium, magnesium and silicate chemistry, that has
enhanced solubility in body fluids
3.1.54
metal fibre reinforcement
stainless-steel needles added to castable for improved toughness and durability
3.1.55
monolithic lining
single-component lining system
3.1.56
mortar
refractory-material preparation used for laying and bonding refractory bricks
3.1.57
multi-component lining
refractory system consisting of two or more layers of different refractory types
NOTE Examples of refractory types are castable, insulating firebrick, firebrick, block, board and ceramic fibre.
3.1.58
multilayer lining
refractory system consisting of two or more layers of the same refractory type
3.1.59
natural-draught heater
heater in which a stack effect induces the combustion air and removes the flue gases
8 © ISO 2012 – All rights reserved

ISO 13705:2012(E)
3.1.60
normal heat release
design heat absorption of the heater divided by the calculated fuel efficiency
3.1.61
pass
stream
flow circuit consisting of one or more tubes in series
3.1.62
pilot
small burner that provides ignition energy to light the main burner
3.1.63
plenum
windbox
chamber surrounding the burners that is used to distribute air to the burners or reduce combustion noise
3.1.64
plug header
cast return bend provided with one or more openings for the purpose of inspection or mechanical tube
cleaning
3.1.65
pressure design code
recognized pressure vessel standard specified or agreed by the purchaser
EXAMPLE ASME Boiler and Pressure Vessel Code, Section VIII.
3.1.66
pressure drop
difference between the inlet and the outlet static pressures between termination points, excluding the static
differential head
3.1.67
primary air
portion of the total combustion air that first mixes with the fuel
3.1.68
protective coating
corrosion-resistant material applied to a metal surface
EXAMPLE Coating on casing plates behind porous refractory materials to protect against sulfur in the flue gases.
3.1.69
radiant section
portion of the heater in which heat is transferred to the tubes primarily by radiation
3.1.70
radiation loss
setting loss
heat lost to the surroundings from the casing of the heater and the ducts and auxiliary equipment (when heat
recovery systems are used)
3.1.71
secondary air
air supplied to the fuel to supplement primary air
ISO 13705:2012(E)
3.1.72
setting
heater casing, brickwork, refractory and insulation, including the tiebacks
3.1.73
shield section
shock section
tubes that shield the remaining convection-section tubes from direct flame radiation
3.1.74
sootblower
device used to remove soot or other deposits from heat-absorbing surfaces in the convection section
NOTE Steam is normally the medium used for soot-blowing.
3.1.75
stack
vertical conduit used to discharge flue gas to the atmosphere
3.1.76
strake
spoiler
metal attachment to a stack that can prevent the formation of von Karman vortices that can cause wind-
induced vibration
3.1.77
structural design code
structural design standard specified or agreed by the purchaser
EXAMPLE International Building Code.
3.1.78
target wall
reradiating wall
vertical refractory firebrick wall which is exposed to direct flame impingement on one or both sides
3.1.79
temperature allowance
number of degrees Celsius (Fahrenheit) to be added to the process fluid temperature to account for flow mal-
distribution and operating unknowns
NOTE The temperature allowance is added to the calculated maximum tube-metal temperature or the equivalent
tube-metal temperature to obtain the design metal temperature
3.1.80
terminal
flanged or welded connection to or from the coil providing for inlet and outlet of fluids
3.1.81
tube guide
device used with vertical tubes to restrict horizontal movement while allowing the tube to expand axially
3.1.82
tube retainer
device used to restrain horizontal radiant tubes from lifting off the intermediate tube supports during operation
3.1.83
tube support
tube sheet
device used to support tubes
10 © ISO 2012 – All rights reserved

ISO 13705:2012(E)
3.1.84
vapour barrier
...