PVC Pressure Pipes & Fittings

About Rendifield MPVC and UPVC pipe

(All tables are best viewed in tablet-mode or on a computer/laptop)

These additives, as well as heat stabilisers and lubricants, which are necessary to facilitate the extrusion of the pipes, are added to the PVC raw material in a special high speed mixer to produce a dry blend specially formulated for the pipe extrusion process.

During the manufacture of the pipe the dry blend is mixed in the extruder and through a combination of heat and shear, the material is ‘gelled’ into a homogeneous molten mass ready for passage through the die and calibrator to form a pipe which has tight tolerances in terms of the outside diameter, wall thickness and mechanical properties.

It should be noted that in recent years heat stabilisers and lubricants have been changed from lead based compounds to alternative, environmentally friendly materials such organic and calcium/zinc compounds.

RENDIFIELD MINING AND INDUSTRIAL PIPING SOLUTIONS has been used successfully in Southern Africa, Australia and New Zealand for over 15 years and is proven as one of the most cost effective and energy efficient piping materials.

The reason for this is the lower long-term safety factor which may be used with tough materials.

Toughness can be defined as resistance to impact and resistance to cracks, i.e. toughness prevents cracks from starting [initiation] and also prevents the propagation of cracks through the pipe wall. Cracks or notches may be initiated during handling or installation or during service due to bending stresses and point loads on the pipe. Brittle failure does not occur with tough materials having predictable failure properties; therefore the material’s toughness bears a direct relationship with the long-term safety factor.

It is now accepted by pipe standards authorities and by the water industry that the 50 year safety factor depends as much on strength as it does on Pipe Standards toughness. Tough materials fail by predictable ductile yielding and hence allow the use of lower safety factors. Thus the 50 year safety factor relates to the type of material and its properties; HOPE has much lower strength than PVC-U but has higher toughness, hence a safety factor of 1.25.

MPVC pipe composition

Polyvinyl Chloride or PVC is one of the most versatile types of pipe materials. It is produced by the polymerisation of vinyl chloride which is made from coal [or oil) and common salt. In fact, salt makes up over 50% of the polymer, thus making PVC one of the most environmentally friendly plastic materials. being least dependent on increasingly scarce hydrocarbon resources.

The unique properties of PVC can be enhanced by the addition of special additives, for example, to create strong yet tough pipe materials such as modified PVC [PVC-M], foamed multilayer sewer and drainage pipes, and weather resistant, above ground drainage pipes. These additives, as well as heat stabilisers and lubricants, which are necessary to facilitate the extrusion of the pipes, are added to the PVC raw material in a special high speed mixer to produce a dry blend specially formulated for the pipe extrusion process. During the manufacture of the pipe the dry blend is mixed in the extruder and through a combination of heat and shear, the material is ‘gelled’ into a homogeneous molten mass ready for passage through the die and calibrator to form a pipe which has tight tolerances in terms of the outside diameter, wall thickness and mechanical properties. It should be noted that in recent years heat stabilisers and lubricants have been changed from lead based compounds to alternative, environmentally friendly materials such organic and calcium/zinc compounds.

MPVC pipe physical properties

Major properties of PVC pressure and sewer and drain pipes are given in the table below. Please note that as with all thermoplastics, properties are dependent on the operating temperature and the duration of the stress application. For example, working pressures of pipes used at higher temperatures should be lowered [or a higher class to be used] in order to maintain the long-term design life of the pipe.

PHYSICAL	UNITS	PVC-U	PVC-M
Co-Efficient of Linear Expansion	k-1	6 X 10-5	6 X 103
Density	Kg/m3	1.4 X 103	1.1.J X 103
Flammability [oxygen index]	%	45	45
Shore Hardness [DJ		70-80	70-80
Softening Point [Vicat- minimum]	“C	> 80	> 80
Specific Heat	J/Kg/K	1.0 X 103	1.0 X 103
Thermal Conductivity [D”C-SO”C]	W/m/K	0.14	0.14

MECHANICAL
Elastic Modulus [long term: 50 years]	MPa	1500	1400
Elastic Modulus [short term: 100 seconds]	MPa	3300	3000
Elongation at break [Minimum]	%	45	45
Poisons Ratio		0.4	0.4
Tensile Strength [50 year – extrapolated]	MPa	26	26
Tensile Strength [short-term / Minimum]	MPa	45	45

FRICTION FACTORS
Manning		0.008-0.009	0.008-0.009
Hazen Williams		150	150
Nikuradse Roughness [k]	mm	0.03	0.03

MPVC Pipe applications

Rendifield MPVC Pipe Systems

SANS 966 Part 1 UPVC – Below -ground pressure applications for the conveyance of potable water in reticulation systems and for other applications in which continuous temperatures in excess of 25 °Care not encountered.
SANS 966 Part 2 [MPVC) – Below-ground pressure applications for the conveyance of potable water in reticulation systems and for other applications in which continuous temperatures in excess of 25 °Care not encountered.
SANS 1283 High Impact – Suitable for the conveyance of nonpotable water at temperatures between 5 °C and 50 °C for underground use in mines.
SANS 1£152-2 – For water supply and for buried and above ground drainage and sewerage under pressure.

MPVC pipe dimensions

All pipes are made to provide an effective length of 6.0 meters from 50 mm – 250 mm and 5.8 meters from 315 mm – 500 mm after installation; the outside diameters are the same for all pressure classes of the same size and there are 6 classes of pipes. The minimum wall thickness and mass per meter are given in the table below.

MPVC features and benefits

Environment-friendly & Lead free material.
Excellent flow characteristics: reduces friction losses.
Best long-term strength [serves in excess of 50 years).
Long-term strength, toughness and stiffness.
Large bore and high flow capacity.
Durability and toughness.
Resistant to acids and alkalis.
Resistant to abrasion, scouring and modern cleaning methods.
Light mass: for easy handling and installation.
Elastomeric locked-in sealing ring system.
Inflammable: Does not support

UPVC pipe composition

Composition of PVC Pipe Materials Polyvinyl Chloride or PVC is one of the most versatile types of pipe materials. It is produced
by the polymerisation of vinyl chloride which is made from coal [or oil) and common salt. In fact, salt makes up over 50% of the polymer, thus making PVC one of the most environmentally friendly plastic materials. being least dependent on increasingly scarce hydrocarbon resources.
The unique properties of PVC can be enhanced by the addition of special additives, for example, to create strong yet tough pipe materials such as modified PVC [PVC-M], foamed multilayer sewer and drainage pipes, and weather resistant, above ground drainage pipes. These additives, as well as heat stabilisers and lubricants, which are necessary to facilitate the extrusion of the pipes, are added to the PVC raw material in a special high speed mixer to produce a dry blend specially formulated for the pipe extrusion process.
During the manufacture of the pipe the dry blend is mixed in the extruder and through a combination of heat and shear, the material is ‘gelled’ into a homogeneous molten mass ready for passage through the die and calibrator to form a pipe which has tight tolerances in terms of the outside diameter, wall thickness and mechanical properties.
It should be noted that in recent years heat stabilisers and lubricants have been changed from lead based compounds to alternative, environmentally friendly materials such organic and calcium/zinc compounds.

UPVC pipe physical properties

PHYSICAL	UNITS	PVC-U	PVC-M
Co-Efficient of Linear Expansion	k-1	6 X 10-5	6 X 103
Density	Kg/m3	1.4 X 103	1.1.J X 103
Flammability [oxygen index]	%	45	45
Shore Hardness [DJ		70-80	70-80
Softening Point [Vicat- minimum]	“C	> 80	> 80
Specific Heat	J/Kg/K	1.0 X 103	1.0 X 103
Thermal Conductivity [D”C-SO”C]	W/m/K	0.14	0.14

MECHANICAL
Elastic Modulus [long term: 50 years]	MPa	1500	1400
Elastic Modulus [short term: 100 seconds]	MPa	3300	3000
Elongation at break [Minimum]	%	45	45
Poisons Ratio		0.4	0.4
Tensile Strength [50 year – extrapolated]	MPa	26	26
Tensile Strength [short-term / Minimum]	MPa	45	45

FRICTION FACTORS
Manning		0.008-0.009	0.008-0.009
Hazen Williams		150	150
Nikuradse Roughness [k]	mm	0.03	0.03

UPVC Pipe applications

Rendifield UPVC Pipe Systems

UPVC Pipe Systems – SANS 966 Part 1 UPVC
Below -ground pressure applications for the conveyance of potable water in reticulation systems and for other applications in which continuous temperatures in excess of 25 °Care not encountered.
SANS 966 Part 2 [MPVC) – Below-ground pressure applications for the conveyance of potable water in reticulation systems and for other applications in which continuous temperatures in excess of 25 °Care not encountered.
SANS 1283 High Impact – Suitable for the conveyance of nonpotable water at temperatures between 5 °C and 50 °C for underground use in mines.
SANS 1£152-2 – For water supply and for buried and above ground drainage and sewerage under pressure.