cpvc versus ppr
TRANSCRIPT
CPVC versus PPRCPVC versus PPR
1. Physical properties 2. Installation Techniques 3. U.V. resistance 4. Fire Related properties
CPVC PVC PPR PEX PB CU
Tensile Strength(MPa at 23°C)
55 50 30 25 27 >300
Coefficient ofThermal Expansion(x10-4 K-1)
0.7 0.7 1.5 1.5 1.3 0.2
Thermal Conductivity(W/MK)
0.14 0.14 0.22 0.22 0.22 >400
LOI 60 45 18 17 18
Oxygen Permeation(cm3/m.day.atmosphere) at 70°C
<1insignificant
(notavailable)similar to
CPVC
(notavailable)similar toPB/PEX
13 16 (notavailable)insignificant
Sources: - Saechtling - International Plastics Handbook - Modern Plastics Encyclopedia
- Chemical engineers Handbook- CEN proposals for European Standards- British Gas
CPVC has excellent properties CPVC has excellent properties compared to PPRcompared to PPR
CPVC versus PPRCPVC versus PPR
CPVC has better physical properties :CPVC has better physical properties :
• PPR has thermal expansion twice that of CPVC(more anchors, loops)
• PPR has thermal conductivity 40% more than CPVC (more insulation)
• PPR has 50% working stress of CPVC(thicker pipe wall, lower water flow)
WALL THICKNESSPN 20 PIPE
OutsideWall thickness (mm)
Diameter (mm) CPVC PP PEX PB
20 1.9 3.4 2.8 2.3
25 2.3 4.2 3.5 2.8
32 3.0 5.4 4.4 3.6
40 3.7 6.7 5.5 4.5
50 4.6 8.4 6.9 5.6
SOURCE : DIN 8077 / 8079 / 16969 / 16893
PN20, 20mm Wall thickness:CPVC : 1.9 mmPP: 3.4 mm
Wall thickness PN20 pipeWall thickness PN20 pipe
CPVC has a higher pressure bearing capability . This leads to same flow rate with smaller pipe size for CPVC.
CPVC versus PPRCPVC versus PPR
Straight professional appearance Need less hangers and supports Less looping
CPVC PPR
CPVC versus PPRCPVC versus PPR
Suitable for vertical risers
CPVC versus PPR CPVC versus PPR easy and cost effective installation easy and cost effective installation
1. Pipe cutter
2. Chamfering tool
3. Solvent cement
All you need is :
Tools required for CPVC are simple and cheap
No need for electrical source
Same procedure for CPVC as for PVC
CPVC versus PPR CPVC versus PPR Installation techniques Installation techniques
• PPR needs more skilled labour
• Single Welding machine can weld jointsup to 32mm only. For larger diameters,more sophisticated welding machines which are heavier and bulkier and not easy to carry(needs more man power) and also needa holding device which is another machine.
• More the machines more the labour.
• Not convenient in congested area, more accidents, more hazardous.
• Need for POWER
CPVC versus PPRCPVC versus PPRInstallation techniques Installation techniques
• Heat fusion leads to ‘bead’ formationinternally and externally. This leads to ample opportunity for bacteria to grow
• Increased frictional loss at every joint
• Reduced flow rate.
• Increased depositions of non solubles
CPVC versus PPRCPVC versus PPRBead Formation in PP Bead Formation in PP
External bead PP socket
PP pipe
Internal beat
CPVC versus PPRCPVC versus PPRBead Formation in PP Bead Formation in PP
CPVC versus PPRCPVC versus PPRBead Formation in PP Bead Formation in PP
U.V. ExposureU.V. Exposure
Polyethylene, PolypropyleneU.V. acts as a strong catalyst for the oxidation process which breaks down polymer chain, leading to weakness in pipe and loss of hydrostatic strength.
CPVCThe main degradation process is dehydrochlorination, not oxidation. This dehydrochlorination, whilst slightly accelerated by U.V., does not break down the polymer chains to any significant extent after outdoor exposure, being mainly limited to a surface discoloration effect.There is a loss of impact resistance due to impact modifiers losing efficiency. This may even result in increased modulus.
No significant loss in pressure bearing capability30 years of outside service in Southern CaliforniaImpact resistance mainly an installation issue (before any UV exposure)
No breakdown of pipe in service
CPVC versus PPRCPVC versus PPRFire related properties Fire related properties
• PP has a Limiting Oxygen Index (% of Oxygen needed in an atmosphere to support combustion)of 17 as compared to 60% of CPVC
• Flash Ignition Temp. of PP is about 340°C ascompared to 480°C for CPVC
• Heat of Combustion of PP is about 3 x more thanCPVC (generating more heat and easy burning)
Low flame spreadLow smoke generationSelf extinguishingNo flaming drips CPVC PP
continues to burn …
HEALTH CONCERNS
Bacterial growth in water piping at 120 days
-
20.000
40.000
60.000
80.000
100.000
120.000
CPVC STEEL COPPER POLYETHYLENE
MATERIAL
CPVC piping supports the lowest bacterial growthcompared with traditional piping materials
Source : Bakterielle Oberflächenbesiedlung in trinkwasserdurchstromtenSchlauch- und Rohrleitungen;Dr. Georg-Joachim Tuschewitzki;Privatdozent am Hygiene-Institut der Universität Bonn;23.10.1989.
BACTERIA
(kBE/cm²)
Dr. G. J. Tuschewitzki
"CPVC piping supports the lowest bacterialgrowth compared with traditional piping materials"
Health ConcernsHealth Concerns
Study: Biofilm Formation Potential of Pipe Materials in internal installations by H.R. Veenendaal / D. van de Kooiy – KIWA(KIWA is the The Netherlands approvals agency for potable water piping systems) - 1999
Number of Legionella bacteria in the test water (average after 8, 12 and 16 weeks - static test, no flow.)
0
50
100
150
200
CPVC(*) StainlessSteel
PEX (*) PB (*) PPR (*)
cfu
/ml
(*) Average of 2 samples
Health Health ConcernsConcerns
″ In the presence of the two CPVC materials, the growth of Legionnella bacteria in the water was low ″