ISO/TR 4191:2014

TECHNICAL ISO/TR
REPORT 4191
Second edition
2014-01-15
Plastics piping systems for water
supply — Unplasticized poly(vinyl
chloride)(PVC-U) and oriented PVC-U
(PVC-O) — Guidance for installation
Systèmes de canalisations en plastique pour l’alimentation en eau —
Polychlorure de vinyle non plastifié (PVC-U) et orienté PVC-U (PVC-O)
— Pratique recommandée pour la pose
Reference number
©
ISO 2014
© ISO 2014
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ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions, symbols, and abbreviations . 2
3.1 Terms and definitions . 2
3.2 Symbols . 4
3.3 Abbreviations . 4
4 Parameters influencing design . 5
4.1 Allowable operating pressure . 5
4.2 Ring stiffness of pipes . 5
5 Hydraulic properties . 7
5.1 Loss of head . 7
6 Assembly methods . 9
6.1 General . 9
6.2 Integral rubber ring joints .13
6.3 Solvent cement joints .14
6.4 Mechanical joints .15
7 Storage, handling, and transport of pipes .15
7.1 Handling.15
7.2 Transport .16
7.3 Storage .16
7.4 Cold bending on site .17
7.5 Anchoring and thrust blocks .19
8 Storage, handling, and transport of fittings, valves, and ancillaries .21
8.1 PVC-U fittings, valves, and ancillaries are light and easy to handle .21
9 Installation .22
9.1 Installation below ground .22
9.2 Pipe deflection .25
9.3 Installation above ground .27
9.4 Installation in ducts .31
10 Commissioning by site pressure testing .31
10.1 General .31
10.2 Preparation for test .31
10.3 Test pressures .35
10.4 Applying the test .35
10.5 Interpretation of results .36
11 Contaminated soil .36
12 Corrosion protection of metal parts .36
13 Pressure surge .37
14 Usage at lower temperature .37
15 Fatigue .37
16 Repairs .38
17 Pipeline detection .39
Annex A (informative) Classification of soils .40
Bibliography .44
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 2, Plastics pipes and fittings for water supplies.
This second edition cancels and replaces the first edition (ISO/TR 4191:1989), which has been technically
revised.
iv © ISO 2014 – All rights reserved

Introduction
This Technical Report is a guidance document and gives a recommended practice for the installation
of unplasticized poly(vinyl chloride) (PVC-U) and oriented unplasticized poly(vinyl chloride) (PVC-O)
piping systems conveying water under pressure for buried and above-ground drainage and sewerage
systems.
Molecular orientation of PVC-U results in the improvement of physical and mechanical properties.
Unless specifically mentioned, the recommendations are valid for both PVC-U and PVC-O and expressed
as PVC.
TECHNICAL REPORT ISO/TR 4191:2014(E)
Plastics piping systems for water supply — Unplasticized
poly(vinyl chloride)(PVC-U) and oriented PVC-U (PVC-O) —
Guidance for installation
1 Scope
This ISO Technical Report gives recommended practices for installation of unplasticized
poly(vinyl chloride) (PVC-U) and oriented unplasticized poly(vinyl chloride) (PVC-O) pipes, fittings,
valves, and ancillaries when used in piping systems conveying water under pressure.
The recommendations are intended to give practical guidance of design and installation of piping
systems incorporating pipes, fittings, valves, and ancillary equipment made from PVC materials and
used for the following purposes:
— water mains and services buried in ground;
— waste water under pressure;
— conveyance of water above ground for both outside and inside buildings,
for the supply of water under pressure at approximately 20 °C (cold water) intended for human
consumption and for general purposes.
This Technical report is also applicable to components for the conveyance of water up to and including
45 °C. For temperatures between 25 °C and 45 °C, Figure 1 of ISO 1452-2:2009 applies.
In addition, recommendations are given for the connection to fittings, valves, and ancillary equipment
made from materials other than PVC.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3, Preferred numbers — Series of preferred numbers
ISO 161-1, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal
pressures — Part 1: Metric series
ISO 1452-1:2009, Plastics piping systems for water supply and for buried and above-ground drainage and
sewerage under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 1: General
ISO 1452-2:2009, Plastics piping systems for water supply and for buried and above-ground drainage and
sewerage under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 2: Pipes
ISO 1452-3, Plastics piping systems for water supply and for buried and above-ground drainage and sewerage
under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 3: Fittings
ISO 1452-4, Plastics piping systems for water supply and for buried and above-ground drainage and sewerage
under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 4: Valves
ISO 1452-5, Plastics piping systems for water supply and for buried and above-ground drainage and sewerage
under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 5: Fitness for purpose of the system
ISO 4065, Thermoplastics pipes — Universal wall thickness table
ISO 4633, Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for
materials
ISO 7387-1, Adhesives with solvents for assembly of PVC-U pipe elements — Characterization — Part 1:
Basic test methods
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
ISO 9311-1, Adhesives for thermoplastic piping systems — Part 1: Determination of film properties
ISO 9969, Thermoplastics pipes — Determination of ring stiffness
ISO/DIS 16422:2013, Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the
conveyance of water under pressure — Specifications
3 Terms and definitions, symbols, and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions in ISO 1452-1:2009 and the following apply.
3.1.1
nominal outside diameter
d
n
numerical designation of size which is common to all components in a thermoplastics piping system
other than flanges and components designated by thread size
Note 1 to entry: It is a convenient round number for reference purposes.
Note 2 to entry: For pipe conforming to ISO 161-1, the nominal outside diameter, expressed in millimetres, is the
minimum mean outside diameter d .
em, min
3.1.2
nominal wall thickness
e
n
specified wall thickness, in millimetres
Note 1 to entry: It is identical to the specified minimum wall thickness at any point e .
y,min
3.1.3
nominal pressure (PN)
alphanumeric designation related to the mechanical characteristics of the components of a piping
system and used for reference purposes
3.1.4
hydrostatic pressure
p
internal pressure applied to a piping system
3.1.5
working pressure (PFA)
maximum pressure which a piping system can sustain in continuous use under given service conditions
without pressure surge
Note 1 to entry: For thermoplastics piping systems, the value of the nominal pressure is equal to the working
pressure at a temperature of 20 °C expressed in bars.
2 © ISO 2014 – All rights reserved

3.1.6
hydrostatic stress
σ
stress induced in the wall of a pipe when it is subjected to internal water pressure
Note 1 to entry: The stress in megapascals is related to the internal pressure, p, in bars, the nominal wall thickness,
e , in millimetres, and the nominal outside diameter of the pipe, d , in millimetres by the following formula:
n n
pd ×−()e
nn
σ =
20e
n
Note 2 to entry: If σ and p are given in the same units, the denominator becomes 2en.
3.1.7
long-term hydrostatic strength at 20 °C
σ
lhts
quantity with the unit of stress, i.e. MPa, which can be considered to be a property of the material under
consideration and which represents the 97,5 % lower confidence limit for the long-term hydrostatic
strength and equals the predicted average strength at a temperature of 20 °C and a time of 50 years with
internal water pressure
Note 1 to entry: ISO 9080 gives the possibility to extrapolate to 100 year lifetime.
3.1.8
lower confidence limit of the predicted hydrostatic strength
σ
LPL
quantity with the dimension of stress, which represents the 97,5 % lower confidence limit of the
predicted hydrostatic strength for a single value at a temperature T and a time t
Note 1 to entry: It is denoted as σ = σ .
LPL (T,t,0,975)
Note 2 to entry: The value of this quantity is determined by the method given in ISO 9080.
3.1.9
minimum required strength
MRS
value of σ rounded to the next lower value of the R 10 series from ISO 3 when σ is below 10 MPa or
LPL LPL
to the next lower value of the R 20 series when σ is higher than 10 MPa
LPL
3.1.10
design coefficient
C
overall coefficient with a value greater than one, which takes into consideration service conditions, as
well as properties of the components of a piping system other than those represented in σ
LPL
3.1.11
pipe series S
dimensionless number for pipe designation (see ISO 4065)
3.1.12
standard dimension ratio
SDR
numerical designation of a pipe series which is a convenient round number approximately equal to the
dimension ratio of the nominal outside diameter, d , and the nominal wall thickness, e
n n
Note 1 to entry: According to ISO 4065, the standard dimension ratio, SDR, and the pipe series S are related as
follows:
[SDR] = 2[S] +1
3.2 Symbols
C design coefficient
d outside diameter (at any point)
e
d mean outside diameter
em
d inside diameter (at any point)
i
d mean inside diameter of socket
im
d nominal (outside or inside) diameter
n
DN nominal size
E wall thickness (at any point)
e mean wall thickness
m
e nominal wall thickness
n
f derating ( uprating) factor for application
A or
f derating factor for temperatures
T
Δ material density
Σ hydrostatic stress
P internal hydrostatic pressure
p test pressure
T
σ design stress
s
σ stress at lower predicted confidence limit
LPL
3.3 Abbreviations
LPL lower predicted confidence limit
MRS minimum required strength
MOP maximum operating pressure
PFA allowable operating pressure
PEA allowable site test pressure
PN nominal pressure
DN nominal diameter
PVC-U unplasticized poly(vinyl chloride)
SDR standard dimension ratio
PVC-O oriented poly(vinyl chloride)
4 © ISO 2014 – All rights reserved

4 Parameters influencing design
4.1 Allowable operating pressure
4.1.1 Where pipe material temperatures do not exceed 25 °C, and where no extra safety considerations
are applicable, nominal pressures are given in Table A.1 of ISO 1452-2:2009 and in Table 2 of
ISO/DIS 16422:2013. These nominal pressures have been calculated on the basis of well-established
data, taking into account a service life of at least 50 years of continuous operation. For common water
supply systems up to 25 °C, the allowable operating pressure PFA in bars (1 bar = 105 N/m2 = 0,1 MPa)
is equal to the nominal pressure, PN.
4.1.2 Design coefficient, C, should comply with those specified in ISO 1452, for PVC-U, and ISO 16422,
for PVC-O.
4.1.3 Where the water service temperature is between 25 °C and 45 °C, it is required that the maximum
allowable pressure is reduced by applying a derating factor, f , as shown in Figure A.1 of ISO 1452-2:2009
T
and Annex C of ISO/DIS 16422:2013.
Figure A.1 of ISO 1452-2:2009 shows that for temperatures up to and including 25 °C, the derating factor
to be applied is 1,0 and for temperatures above 25 °C, the derating factor reduces from 1,0 to 0,63 at
45 °C. The same is valid for PVC-O pipes.
Where water service temperatures are expected to exceed 45 °C, the manufacturer’s advice should be
obtained.
4.2 Ring stiffness of pipes
Where a calculation of the initial pipe deflection is applied, the initial ring stiffness of the pipe should be
taken from Table 1.
Table 1 — Initial ring stiffness of pipes
Pipe series
S 20 S 16,7 S 16 S 12,5 S 10 S 8 S 6,3 S 5
(SDR 41) (SDR 34,4) (SDR 33) (SDR 26) (SDR 21) (SDR 17) (SDR 13,6) (SDR 11)
Nominal pressure − PN 6 PN 6 PN 8 PN 10 PN 12,5 PN 16 PN 20
PN 6 PN 7,5 PN 8 PN 10 PN 12,5 PN 16 PN 20 PN 25
for d ≤90
n
for d >90
n
Calculated ring 3,9 6,7 7,6 16 31,3 61 125 250
stiffness in kN/m
(S
calc)
Nominal ring stiff-
4 8 − 16 32 − − −
ness SN
The initial ring stiffness S in Table 1 has been calculated using the following formula:
calc
E×I E
S = =
calc
()de− 96[]S
en
(1)
where
S is the calculated initial ring stiffness in kilonewtons per square metre;
calc
E is the modulus of elasticity in flexure, having the value of 3,2 × 106 kN/m2 for PVC-U and
having the value of 4 × 106 kN/m2 for PVC-O;
1×e
n
Ι is the moment of inertia in cubic millimetres with for 1 m pipe length;
d is the nominal outside diameter in millimetres;
e
e is the nominal wall thickness in millimetres;
n
S is the pipe series.
The initial ring stiffness of PVC-O pipes with the different MRS values are given in the graphs of Figure 1.
6 2 6 2
E: PVC-O: 4 × 10 kN/m (4 000 Mpa) E: PVC-U: 3,2 × 10 kN/m (3 200 Mpa).
NOTE The following C factor has been used: MRS 250 (PVC-U): C = 2,0; PVC-O: C = 1,6.
6 © ISO 2014 – All rights reserved

NOTE The following C factor has been used: PVC-O: C = 1,4.
Figure 1 — Initial ring stiffness of pipes of PVC-O
In case the actual modulus measured or stated by the manufacturer or designer is known, then use the
following correction formulae:
For PVC-U: SN = SN1 × E/3 200
For PVC-O: SN = SN1 × E/4 000
(SN1 = taken from the graph)
5 Hydraulic properties
5.1 Loss of head
For head losses through fittings, the manufacturer’s advice should be obtained.
PVC pressure pipes are specified by nominal diameters, d . Internal diameters vary according to pipe
n
series (see Table 2 of ISO 1452-2:2009 and ISO/DIS 16422:2013). This shall be taken into account when
calculating the flow characteristics of pipes.
The flow is characterized by the Reynolds number as follows:
Re = v × dh/µ (2)
where
Re is the Reynolds number [-];
v is the flow speed [m/s];
µ is the kinematic viscosity [m /s].
The friction value f is then calculated by an iterative manner using Formula (3):
 
1 ε/D 25, 1
h
=−2log +
 
 
37,
f Re f
 
(3)
where
D is the hydraulic diameter (for a circular pipe, full flow = internal pipe diameter) [m];
h
Re is the Reynolds number [-];
ε is the roughness of the pipe [m].
And finally, the pressure loss is calculated by
L ρV
Δpf=× ×
D 2
(4)
where
∆p is the pressure loss [m];
f friction value;
L is the length of the pipe [m];
D is the internal diameter of the pipe [m];
ρ is the density of the fluid [kg/m ];
V is the flow speed [m/s].
8 © ISO 2014 – All rights reserved

Figure 2 — Example of flow chart for head losses in pipes
Figure 2 comprises the friction loss diagram for PVC-U pipes calculated by L-E Janson in accordance with
Colebrook. For internal diameters up to 200 mm, k = 0,02 mm and for larger diameters, k = 0,05 mm. The
temperature of the water is ±10 °C.
6 Assembly methods
6.1 General
6.1.1 PVC pressure pipes conforming to ISO 1452-2:2009 are supplied in nominal lengths and with one
of the following three end conditions:
a) plain, for jointing by means of separate couplers;
b) integral elastomeric ring socket (one end), for push-fit jointing;
c) integral socket (one end), for solvent cement jointing.
6.1.2 Fittings of PVC for use with PVC pipes are specified in ISO 1452-3 and can either have socket-type
joints for solvent cementing or elastomeric ring joints for push-fit jointing. Valves and ancillaries of PVC-U
are specified in ISO 1452-4.
6.1.3 The principal types of joints and their characteristics are as follows:
a) Lastomeric ring seal joints (see Figure 3). An elastomeric sealing ring is compressed and forms
a pressure-tight seal when a spigot is inserted into a socket. These joints do not sustain axial thrust
(non-end-load-bearing).
Figure 3 — Typical elastomeric ring seal joints
b) Solvent cement joints (see Figure 4). A solvent-based adhesive is applied to a spigot and to a
socket and the two components are pushed together. Solvent-cemented joints sustain axial thrust (end-
load-bearing).
Figure 4 — Typical solvent cement joints
c) Mechanical joints (see Figure 5). These joints can be either end-load-bearing or non-end-load-
bearing.
10 © ISO 2014 – All rights reserved

Figure 5 — Typical mechanical joint
These joints, also known as compression joints, use separate couplers made from PVC-U, reinforced
plastics or metal, e.g. cast iron. A pressure-tight seal is achieved when an elastomeric sealing ring is
compressed by tightening backing ring(s) of various designs. These joints may or may not sustain axial
thrust (non-end-load-bearing). For the choice of specific mechanical couplers, advice shall be sought at
the manufacturer of the PVC pipes.
d) Flanged joints (see Figure 6). A flange is incorporated onto the end of a pipe or fitting in a
variety of ways. A pressure-tight seal is achieved by compressing a sealing gasket between the mating
faces of flanges on adjacent pipes, fittings, or valves made from plastics or metals. These joints can be
either end-load-bearing or non-end-load-bearing.
Figure 6 — Example of flanged joints
e) Union couplers and adaptors (see Figure 7). Union couplers and adaptors can be used for joint-
ing PVC pipes to PVC pipes and PVC pipes to metal pipe threads. Union couplers and adaptors sustain
axial thrust (end-load-bearing).
Figure 7 — Union couplers and adaptors
Where pipe installations include non-end-load-bearing jointing systems (above or below ground), it is
essential to consider the probability of joint separation due to axial thrust.
In below-ground applications, joint separation can be prevented by means of end-load-bearing joints or
concrete anchor blocks (see Figure 8).
12 © ISO 2014 – All rights reserved

Figure 8 — Typical anchor block arrangements
Joint separation in above-ground applications can be prevented by properly designed anchor brackets
or more easily by use of end-load-bearing jointing systems (see 7.5).
When evaluating the axial thrust, the test pressure shall be considered.
6.2 Integral rubber ring joints
6.2.1 Elastomeric sealing rings are usually made from synthetic materials, e.g. ethylene-propylene-
diene (EPDM) copolymer, styrene-butadiene rubber (SBR), or a combination of synthetic and natural
rubber. Profiles of the ring and of the socket depend on individual manufacturers’ designs. The rings to be
used should be those supplied by the manufacturer for his own assembly system. If the sealing ring is not
in place at the time of delivery, the groove should be cleaned, any foreign bodies should be removed, and
the ring should be located into the groove as directed by the manufacturer. Sealing ring materials shall
fulfil the requirements as specified in EN 681-1 or ISO 4633.
6.2.2 Integral elastomeric ring joints do not normally sustain end thrust. Particular attention should be
paid to the correct design of anchor blocks and to their location in the pipeline system (see 7.5).
In some countries, it is common practice to provide restraint against thrust by the inclusion of end-load-
bearing joints at strategic points within the system. Where this practice is acceptable, the pipe and/or
fittings manufacturer’s advice should be sought to help identify the places where end-load-bearing
joints should be applied (see 7.5).
6.2.3 Before assembling both, the elastomeric ring and spigot should be inspected and cleaned.
6.2.4 The correct assembly of an elastomeric ring seal joint requires that the spigot end of the pipe be
chamfered and correctly lubricated prior to insertion into the socket. Lubricant should also be applied to
the elastomeric ring once this is fitted into the ring groove.
The lubricant used should not have any detrimental effect on the pipe, fittings, ancillaries, or elastomeric
sealing ring and shall not be toxic, shall not impart any taste or odour to the water, and shall not encourage
the growth of bacteria.
In conformity to 4.2 of ISO 1452-1:2009, the lubricant should have no influence on water quality. Only
lubricants recommended by the pipe or fittings supplier should be used.
As soon as the pipe spigot and elastomeric ring have been lubricated, the spigot should be introduced
into the socket so as to avoid any risk of soiling or pollution.
After aligning the pipes in both horizontal and vertical planes, the spigot end should be inserted into the
socket up to the reference mark on the spigot.
Pipes may be cut on site. If this is necessary, the cut should be square and the cut end deburred and/or
chamfered to the angle and dimensions given in ISO 1452-2:2009.
6.3 Solvent cement joints
6.3.1 General
6.3.1.1 The dimensions of the sockets and spigots for solvent cement joints are given in ISO 1452.
6.3.1.2 The solvent cement adhesives identification characteristics should be specified by the
manufacturer according to ISO 7387-1 and their properties shall conform to ISO 9311-1.
The adhesive(s) should have no detrimental effects on the pipe and shall not cause the test assembly to
fail to conform to ISO 1452-5.
6.3.1.3 In conformity to ISO 1452, the solvent cements should have no influence on water quality.
6.3.2 Jointing operations
6.3.2.1 Solvent cement adhesives and cleaning fluids are flammable, therefore it is important that
smoking or any other sources of ignition should be prohibited in the area in which these materials are
being used. Solvent cement operations should be carried out in a well-ventilated area. Specific instructions
can be found on the package of the Solvent cement.
6.3.2.2 The pipe end to be jointed should be cut square to its axis and free from irregularities such as
burrs and swarf to prevent excessive amounts of adhesive being scraped off the socket. Chamfered pipes
should not be used for solvent cementing. When the chamfer is applied on site, the angle and dimensions
should conform to ISO 1452-2:2009.
6.3.2.3 The surfaces to be jointed should be clean, dry, and free from grease. It is recommended that a
degreasing agent is used for this purpose in accordance with manufacturer’s recommendations.
6.3.2.4 The solvent cement should be applied in an even layer and in a longitudinal direction to both
spigot and socket mating surfaces.
6.3.2.5 The application of the solvent cement should be performed quickly. For diameters greater than
110 mm, two persons are necessary to apply the adhesive, one to the spigot end and one to the socket
simultaneously. The size of the brush shall be in accordance with the manufacturer’s instructions. It is
recommended to take the brush size approximately 1/3 of the diameter of the pipe.
6.3.2.6 Immediately and without twisting, the spigot should be pushed into the socket to the required
depth. Excessive amounts of adhesive around the socket mouth should be removed as soon as the joint
has been made. Once the joint is made, leave to dry without disturbing for at least 5 min.
14 © ISO 2014 – All rights reserved

6.3.2.7 The joint becomes resistant to pressure only after an additional period. Allow the required
minimum time given by the pipe manufacturers before applying the maximum recommended test
pressure (see Figure 11).
NOTE 1 Solvent cements are slow to cure at low temperatures and cure fast at high temperatures. Solvent
cementing is not recommended at temperatures of 0 °C and below.
NOTE 2 Solvent cements for joints >250 mm is not recommended on the installation site.
6.4 Mechanical joints
6.4.1 Compression joints
Compression joints are normally separate fittings made from PVC-U, reinforced plastics or metal and
can be in the form of a coupler for connecting pipes and fittings of the same material and of the same
dimensions or as an adaptor for connecting components of different materials and/or dimensions.
Generally, compression fittings consist of the following four main elements:
a) body;
b) elastomeric sealing rings;
c) backing (compression) rings;
d) nuts or bolts.
Each element is positioned on the pipe separately and the sealing rings compressed between the body
of the fitting and the pipe by tightening the backing rings. Nuts or bolts should be correctly tightened in
accordance with the manufacturer’s recommendations at all stages of assembly.
6.4.2 Threaded joints
There is a range of threaded joints for assembly to metallic pipes, including the following:
a) PVC-U and metal union adaptor;
b) PVC-U adaptor fittings.
PVC pipes conforming to ISO 1452-2:2009 and ISO 16422 are not recommended for threading in pressure
application.
6.4.3 Flanged joints
PVC pipes, fittings, and ancillaries can be supplied with flanged ends. Although detailed flange designs
vary considerably, all are suitable for connection to pipes, fittings, and valves made from other materials,
e.g. metals. A pressure-tight joint is obtained by compressing a gasket or ring between the mating faces
of adjacent flanges.
7 Storage, handling, and transport of pipes
7.1 Handling
When pipes are to be handled individually, they should be lowered, lifted, and carried in a controlled
fashion and should never be thrown, dropped, or dragged. Single pipes up to nominal size 250 mm can
be handled by two men without difficulty. Pipes of larger nominal size can require lifting apparatus, as
with bundles.
7.2 Transport
When transporting pipes, flatbed vehicles should be used. The bed should be free from nails and other
projections. When practicable, package of pipes should be transported in original package or scalp
timbers if possible.
The vehicles should have side supports appropriately spaced approximately 2 m apart, and the pipes
should be secured effectively during transport. All posts should be flat with no sharp edges.
When loading socketed pipes, the pipes should be stacked on the vehicle so that the sockets do not take
excessive loads.
Where pipes overhang the vehicle, the amount of overhang should not exceed 1 m.
Unloading bundled pipes require the use of appropriate mechanical equipment. The chosen technique
should not cause damage to the pipes, e.g. forklift truck with flat protected forks or suitable crane with
spreader bars. PVC pipes should never be lifted using wire ropes and slings or metal hooks and chains.
Slings should be non-metallic, e.g. rope or webbing.
Pipes should not be covered where temperatures may rise to unaccepted levels. Pipes having a ring
stiffness lower than 4 should be stacked with intermediate scaffold wooden battens. Pipes should be
arranged in a package in such a way that the socket and spigot ends are arranged in an alternate fashion.
7.3 Storage
PVC pipes are light and easy to handle and consequently likely to be mistreated for that reason.
Appropriate precautions should be taken during handling and storage to ensure that pipes are not
damaged.
In depots or stores, bundled pipes should be stacked no more than three units or 2 m high, whichever is
lower. At the construction site, bundles should be stacked no more than two units or 1 m high, whichever
is lower. If the bundles are timber framed, they should be stacked timber to timber. Provision should be
made for side supports, to prevent stack collapse, when banding or framing is removed. Side supports
should be spaced at centres not greater than 3 m (see Figure 9).
Where pipes are supplied with end caps, plugs, or wrappings, these should not be removed before the
pipes are put in place. Contact with fuels and solvents should be avoided during storage.
Prolonged exposure to strong ultraviolet light (sunlight) can slightly reduce the impact strength of PVC
pipes and cause discoloration. Nevertheless, the resistance to internal water pressure is not reduced.
Suitable protection by a free-venting opaque cover (canvas or polyethylene sheeting) is recommended if
the total exposed storage time is likely to exceed 12 months.
In case sunlight results in very high surface temperatures, then also free-venting opaque cover should
be applied. When pipes may become very hot (approximate more than 60 °C), then the integral sockets
may change shape slightly, causing possible assembly problems.
16 © ISO 2014 – All rights reserved

Key
1 non-metallic wide band webbing
2 webbing positioned outside timber battans
3 additional support battans
4 strapped timber battans
a
Lifting bundlepacks by crane.
Figure 9 — Handling and storage
7.4 Cold bending on site
Cold bending on site is permitted for pipes to deviate from one continuous straight line by the following
techniques:
a) means of a slight deflection within an elastomeric ring joint;
b) the gradual curvature of each pipe length.
To ensure that the efficiency of the elastomeric ring seal is not impaired, deflection within the joint
would normally be limited to a maximum of 1°. For greater deflections, special designs of joint should be
used and the manufacturer’s advice obtained.
The radius of curvature, R, of a cold-formed bend over the length of a 6 m pipe shall not be less than 300
times the external diameter of the pipe (see Figure 10).
Table 2 gives useful dimensions for cold-bent PVC-U pipes up to and including DN 160 for PN 16 pipes. To
avoid uncontrolled angle deflection, the pipe end in the socket should be fixed.
Table 3 gives useful dimensions for cold-bent PVC-O pipes up to and including DN 160.
Ferrule straps or house connections should preferably not be applied to bend sections, unless otherwise
recommended by the supplier.
∅ = Max. OD pipe
R = 200 ∅
180L
α =
π R

α
SR=×2 sin

α
AS=×sin

α
BR=−R×cos
Figure 10 — Dimensions relating to pipe curvature
Table 2 — Allowable bending radii for PVC-U pipes
(Effective bending length L = 6,0 m, R = 200 × d)
DN Minimum radius Angle Chord Deflection
PVC-U
[mm] α/2 S [m] A [m]
[m]
63 12,6 13,64 5,94 1,40
75 15,0 11,50 5,98 1,19
90 18,0 9,55 5,97 0,99
110 22,0 7,81 5,98 0,81
125 25,0 6,87 5,98 0,72
140 28,0 6,14 5,78 0,64
160 32,0 5,37 5,99 0,56
180 — — — —
18 © ISO 2014 – All rights reserved

Table 3 — Allowable bending radii for PVC-O pipes
(Effective bending length L = 6,0 m, R = 120 × D)
DN Minimum radius Angle Chord Deflection
PVC-O
[mm] α/2 S [m] A [m]
[m]
63 7,56 22,70 5,84 2,25
75 9,00 19,08 5,88 1,92
90 10,80 15,90 5,92 1,62
110 13,20 13,02 5,94 1,34
125 15,00 11,45 5,96 1,18
140 16,80 10,23 5,96 1,06
160 19,20 8,90 5,97 0,92
180 – – – –
Other combination of bending radius and diameter can be calculated using the formulas in Figure 10.
For practical reasons, the bending moment should not become higher than 1000 kNm.
This bending moment can be calculated with M = R /E .
I
7.5 Anchoring and thrust blocks
Systems with non-tensile-resistant joints may require thrust support at fittings.
At any change in pipe direction or size or at any branch, valve, or end fitting, pressure thrusts arise which
should be countered by the pipe system itself or by appropriate anchorages transferring the thrust back
to the soil or supporting structure. A table of forces generated is given in Table 4. In addition, external
torque and bending loads on valves and hydrants can be significant, and design shall provide reaction
that will guard against excessive loading on the pipe.
Table 4 — Thrust forces for blank ends and bends
Nominal Radial thrust on bends of various angles
Thrust on
diameter
a
kN/bar
blank end
d
n
a
kN/bar
90° 45° 22,5° 11,25°
mm
63 0,31 0,44 0,24 0,12 0,06
75 0,44 0,62 0,34 0,17 0,09
90 0,64 0,90 0,49 0,25 0,12
110 0,95 1,34 0,73 0,37 0,19
125 1,23 1,74 0,94 0,48 0,24
140 1,54 2,18 1,18 0,60 0,30
160 2,01 2,84 1,54 0,78 0,39
180 2,54 3,60 1,95 0,99 0,50
200 3,14 4,44 2,40 1,23 0,62
225 3,98 5,62 3,04 1,55 0,78
250 4,91 6,94 3,76 1,92 0,96
280 6,16 8,71 4,71 2,40 1,21
315 7,79 11,02 5,96 3,04 1,53
355 9,90 14,00 7,58 3,86 1,94
400 12,57 17,
...