flowguard vs ppr presentation 2014 - alwaab plastics

1 © 2014 The Lubrizol Corporation, all rights reserved. All marks are property of The Lubrizol Corporation, a Berkshire Hathaway Company.

© 2014 The Lubrizol Corporation, all rights reserved. All marks are property of The Lubrizol Corporation, a Berkshire Hathaway Company.

Surpass Polypropylene Limitations with

Reliable FlowGuard™ CPVC


FlowGuard CPVC advantages over PPR

Better Antimicrobial Performance

Eco Friendly

Long Term Performance

Easy Repairs

Quality Assured

Excellent Physical Properties

Superior Installation

UV Resistant

Chlorine Resistant

Fire Resistant


CPVC vs PPR - Physical Properties

CPVC PPR

Tensile Strength (Mpa at 23°C)

55 30

Coefficient of Thermal Expansion (x10-4 K-1)

0.7 1.5

Thermal Conductivity (W/MK)

0.14 0.22

Oxygen Permeation (cm³/m.day.atmosphere) at 70°C

<1 insignificant

13

Sources: Saechtling – Intl. Plastics Handbook, Modern Plastics Encyclopedia, Chemical engineers Handbook, British Gas

: - Needs less hangers and supports - No ‘looping’ of the pipe - Higher pressure bearing capability, same flow rate with smaller pipe size

CPVC:



CPVC PPR

- Straight professional appearance - Need less hangers and supports - Less looping

CPVC:



CPVC PPR

- Suitable for vertical risers

CPVC:



Source : DIN 8077/8079/16969/16893

: Has a higher pressure bearing capability. This leads to same flow rate with smaller pipe size

CPVC:

PN20, 20mm Wall thickness: CPVC : 1.9 mm PP: 3.4 mm

WALL THICKNESS

PN 20 PIPE

Outside

Wall 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


Installation Techniques

Tools required are simple and cheap.

Solvent welding process allows for fast

and easy assembly.

Same procedure for CPVC as for PVC

Chemically welded joints are the strongest part of the system.

No need for electrical source.

CPVC: Solvent Welding Only tools required:

CPVC SOLVENT CEMENT



CPVC: Solvent Cement Mechanism

Plastic Fitting

Plastic Pipe

Cement

Plastic Fitting

Plastic Pipe

Plastic pipe and fittings are composed of large polymer molecules (illustrated by ). Solvent cement is made by dissolving a polymer in a liquid. When solvent cement is applied to the plastic part, the liquid penetrates the surface and softens the outer layer of the plastic part. The polymer chains then interpenetrate with one another to form a strong cohesive bond.

Cohesive bond formed



: - Need of expensive welding machine for

each worker on site. PPR needs more skilled labour. Labour intensive and difficult to install in

tight places Single welding machine can weld joints

up to 32mm only. Large pipe sizes require an even more

labour intensive process using specialized and expensive equipment.

Fusion welding tool heats up to 250°C, posing a burn hazard and adds time to installation process.

Requires an electrical source.

PPR: Fusion Welding

Welding machine/tools for larger sizes



PPR: Fusion Welding

Heat fusion leads to ‘bead formation’ internally and externally

• Increased friction loss at every joint

• Reduced flow rate

• Ample opportunity for bacterial growth

• Increased depositions of non solubles



Requires additional space to

perform, leading to a need to pre-fabricate large frames for subsequent fixing in the wall.

Not convenient in congested

area.

PPR : Fusion Welding


: - The 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.

CPVC : : - - U.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.

PPR :

CPVC vs PPR - UV Resistance


Natural Weathering Effects on some properties of CPVC material

CPVC study :

CPVC vs PPR - UV Resistance

- Samples from locally manufactured CPVC commercial pipes have been naturally weathered for different periods in harsh Saudi weather conditions.

- Standard tensile and SEN fracture toughness tests were performed after natural exposure periods of 1,2,3,6 and 9 months

The tensile test results showed that exposure for periods up to 9 months, including summer season, had limited effects on the tensile strength and modulus of elasticity of the material. The damage due to weathering is mainly a surface phenomenon.

Source: Study from Mechanical Engineering Dept. - King Fahd University of Petroleum & Minerals , Dhahran, Saudi Arabia - 2007


CPVC / PPR and Chlorine

Polymer Chemistry : When chlorine is added to water for disinfection, it

transforms to hypochlorous acid.

Hypochlorous acid is a strong oxidizer which is capable of breaking the

carbon-to-carbon bonds of the polymer chain, effectively disintegrating it.

The chlorine atoms surrounding the carbon chain of CPVC, however, are large atoms which protect the chain from attack by hypochlorous acid in the water.

CPVC:

The hydrogen atoms surrounding the carbon chain of polyolefins, such as PPR, PEX and polybutylene, are small atoms which are incapable of protecting the chain from attack by hypochlorous acid in the water.

PPR:



Hydrogen

... ...

Carbon

Chlorine

Access to the CPVC carbon chain is restricted by the chlorine on the molecule CPVC:

Any chlorine which actually reaches the backbone, simply chlorinates it further. The effect is the same as the resin chlorination process.



PPR:

Carbon

Hydrogen Chlorine

Oxygen

Hypochlorous acid attack on polypropylene

Carbon

Hydrogen Chlorine

Oxygen

Bonds are broken at tertiary carbon sites



Dip Tube -Issue Mid 90’s, in the US, PPR pipe

was used in a non-pressure, water heater application.

Device introducing water into a heater at the bottom of heater.

The tube transits through hot water of tank experiencing elevated temperatures in the presence of disinfectants.

PP tubing degraded into powder plugging up components like valves and pressure relief safety devices.

Major recall, PP tubes not used since.

This effect has been seen in practical situations

Anode Rod

DIP TUBE

Steel Tank

Insulation

Outer Case

Drain Valve

HOT COLD

OUT IN

Temperature/

Pressure

Relief

Valve

Electric

Heating

Elements

Thermostat



www.bodycote.com

Bodycote Polymer AB, leading pipe test lab in the world

Identified the chlorine failure mechanism in PP, PE-X and PB piping

A considerable amount of data has been generated which demonstrates without doubt that small quantities of chlorine exhibit a strong oxidizing effect on polyolefin pipes resulting in a significant reduction of the expected lifetime

And studied by many leading test labs

http://mt.bodycote.com/


Chlorine resistance testing

Results & experiences from tests on polyolefin pipes exposed to chlorinated water

Source: Studsvik Polymer AB – Sweden / Tokyo Gas Co., Ltd. – Japan ( presented at the Plastic Pipes X Conference 1998 )

Material ( Specimen )

Hoop Stress

( Mpa )

Chlorine Concentr. ( ppm)

Failure Time

( hours )

Relative Failure Time

PO – A

1.4

3

831

1

PO – A

1.4

1

1428

1.7

PO – A

0.7

3

1334

1

PO – A

0.7

1

2752

2.1

PO – B

1.4

3

837

1

PO – B

1.4

0.5

1161

1.4

PO – B

0.7

3

1435

1

PO – B

0.7

0.5

2111

1.5

PO – C

1.1

3

1007

1

PO – C

1.1

0.5

1451

1.4

PO – C

0.6

3

1086

1

PO - C

0.6

0.5

1848

1.7



NSF P171 Protocol

Two End-Use Conditions:

Continuous re-circulation (Cl-R)

100% at 60o C

4 ppm chlorine, 6.8 pH

Minimum extrapolation is 80 years with no safety factor

Traditional domestic (Cl-TD)

25% at 60o C, 75% at 23o C

4 ppm chlorine, 6.8 pH

Minimum extrapolation is 80 years with no safety factor

Incr

easi

ng

Test

ing

Seve

rity



PPR Manufacturer A Tested in general accordance with

NSF P-171 Protocol for Chlorine Resistance of Plastic Piping Materials and ASTM F-2023-04 Test Method for Evaluating the Oxidative Resistance of PEX Tubing and Systems to Hot Chlorinated Water.

Significant erosion of pipe wall after

testing (up to 50% after 7000 hrs) using low water flowrate (~0.1 gpm).

Similar phenomenon as in dip tubes.

PR Manufacturer B

PPR testing

Before After

PPR Manufacturer A


CPVC : Real Life testing


CPVC plumbing pipe installed in Baltimore, Mary land in 1960’s.

No erosion of pipe wall after 23 years of installation.

No decrease in long term hydrostatic performance.


Warning letter from Plastics

Industry Pipe Association in

Australia - premature aging

of polyolefin pipes are

causing concerns!




Classes of PPR damage seen in re-circulating hot water loop in Australia

Whitening and deposition of powder in pipe interior that may be either localized or uniform

Brittle cracking along stress lines in joins, elbows and other welded-in fittings

Cracking by prevention of thermal expansion by incorrect clipping

Longitudinal brittle crack in pipe under stress


Fire Related properties

- Low flame spread and smoke generation - Self extinguishing - No flaming drips

CPVC:

CPVC PPR

Limiting Oxygen Index (% of Oxygen needed in an atmosphere to support combustion)

60

17

Flash Ignition Temperature 480°C 340°C

Heat of combustion of PPR is about 3x more than CPVC generating more heat and easy burning


CPVC and Fire Resistance Testing

The best possible rating a non-metal material can receive

Fire behavior B → Low flammability, no contribution to flashover

Smoke development s1 → Low smoke development

Flaming droplets d0 → No burning drops

EN 13501-1:2002 – Fire classification of construction products and building elements

CPVC rating = B s1 d0


CPVC vs PPR: Antimicrobial Performance

Dr. Paul Sturman concludes:

“CPVC consistently

outperforms most other non-

metallic piping materials with

regard to its ability to resist

the formation of biofilms”.

Source: Assessment of the Microbial Growth Potential of Materials in

Contact with Treated Water Intended for Human Consumption, KIWA, 2007

Source: Dr. Paul Sturman, research professor and industrial coordinator for

The Center for Biofilm Engineering at Montana State University based on

his evaluation of Dutch Research and Knowledge Institute for Drinking

Water (KIWA) 1999 study Biofilm Formation Potential of Pipe Materials in

Plumbing Systems, 2006 study Standardizing the Biomass Production

Potential Method for Determining the Enhancement of Microbial Growth by

Construction Products in Contact With Drinking Water, and 2007 study

Assessment of the Microbial Growth Potential of Materials in Contact with

Treated Water Intended for Human Consumption


CPVC vsPPR: Antimicrobial Performance

0

200

400

600

800

1000

1200

1400

pg

AT

P/c

m²

Copper CPVC Inox 304 Inox 316 Polybutene Polypropylene

Comparison of BPP (Biomass Production Potential) values*

observed at 30°C and 50°C

BPP at 30°C BPP at 50°C

* Values measured at 8, 12 and 16 weeks (Inox 304/316 = Stainless Steel )

Study conducted by CRECEP in France, confirm the ability of CPVC to resist biofilm formation

Source: Study of 6 different materials used for drinking water distribution and their capacity to support bacterial growth conducted by Crecep (Research

and Control of drinking water Centre in Paris) according to a European standard project by means of the Biomass Production Potential test in 2005.


CPVC vs PPR: Antimicrobial Performance

Study: Biofilm Formation Potential of Pipe Materials in internal installations by H.R. Veenendaal / D. van de Kooiy – KIWA - 1999 (KIWA is the approvals agency for potable water piping systems in The Netherlands)

″ In the presence of the two CPVC materials, the growth of Legionnella bacteria in the water was low ″


CPVC vs PPR: Environmental Impact

Total energy requirements for CPVC production are lower than other plastic materials, due primarily to the low petroleum content.

Source: H. Sambele, Kapitel Nachchlorierte Polyvinylchloride Rohre, Technical University Berlin, 1993


CPVC vs PPR: Recycling

: • PVC piping can easily be recycled

as PVC piping or window profiles

• Piping material can be collected from the jobsite by a specialized recycling firm (country specific)

• Regrind piping material into pellets and granules

• Mix regrind into applications such as floor fillings, floor coatings, cable trays, speed bumps and car mats.

CPVC : • : - • Cannot meet the strength and

performance requirements of many applications without fiberglass reinforcement

• More expensive and not recyclable due to its fiberglass layer

PPR :


CPVC vs PPR: Long term performance

LTHS Performance at 95°C

1

10

1 10 100 1000 10000 100000 1000000

Time (hours)

Ho

op

Str

es

s (

MP

a)

PPR

CPVC

Reference curves for expected strength at 95°C

CPVC

PPR

Hyd

rost

atic

str

ess,

in M

pa

Time to fracture, in hours

Source: EN ISO 15874-2 / EN ISO 15877-2


CPVC vs PPR: Repairs

: • On line repairs - punctures could

be repaired like a patch made from section of a pipe and solvent cemented in situ without dismantling the pipe

• Similarly, if any additional fitting needs to be added or replaced, it is easy.

• Training to plumbers : Lubrizol as raw material supplier and our FlowGuard licensees train the plumbers

CPVC : • : - • On line repairs – In case of

punctures, one has to cut open a pipe line and repairs are done with the socket

• If any additional fitting of higher diameter needs to be added or replaced, the pipe line has to be dismantled due to heavy tooling needed for heat fusion, or one has to use electro fusion fittings which are expensive

PPR :


CPVC vs PPR: Repairs

Perception of PPR in Mature Markets

India • Joint blockages lead to heavy losses to

the builders as they had to cut open tiles and walls to redo and correct the piping.

• Repairs and reconnections very

cumbersome and time consuming


CPVC: Quality Assurance

: FlowGuard CPVC products: • Must conform to appropriate

national standards • And must comply with the

Lubrizol quality of pipe/fitting program!

• Tested at manufacturing site and at Lubrizol labs in USA and Europe: - Dimensions - Flattening - Pressure tests - Impact - Heat reversion

CPVC:

The globally established FlowGuard brand assures quality!


© 2014 The Lubrizol Corporation, all rights reserved. All marks are property of The Lubrizol Corporation, a Berkshire Hathaway Company.

Back-up slides: 1. Thermal expansion and contraction

2. CPVC in walls, concrete

3. Thermal insulation

4. Scale build up

5. Condensation

6. CPVC with chilled water systems

7. Quieter than copper / Water Hammer


Thermal expansion and Contraction



Table I. Calculated expansion loop lengths for CPVC Schedule 80 piping with DT of 80°F (44°C)

Length of run in feet (meters)

Nominal

Size 20 (6) 40 (12) 60 (18) 80 (24) 100 (30) 1/2" 18 (46) 25 (63) 31 (79) 36 (91) 40 (101) 3/4" 20 (51) 28 (71) 35 (89) 40 (101) 45 (114) 1" 22 (56) 32 (81) 39 (99) 45 (114) 50 (127) 1¼" 25 (64) 36 (91) 43 (109) 50 (127) 56 (142) 1½" 27 (69) 38 (97) 47 (119) 54 (137) 60 (152) 2" 30 (76) 42 (107) 52 (132) 60 (152) 67 (170)



An example was selected from the guide in Table I to demonstrate the use of these data in the following three methods of compensating for the thermal expansion. Example : Pipe size = 1/2 in. Length of run = 60 ft. (18m) ’L ’ = 31 in. (79 cm) ( from table)

6" min. 6" min. L/4

LOOP OFFSET CHANGE IN DIRECTION

Do not butt up against fixed

structures (joist, stud, wall)

2L/5

(12" or 32 cm)

L/2

(16" or 40 cm)

L

(31" or 79 cm)


40


Example of loop allowing thermal expansion


Expansion loop requirements

C is greater than C CPVC Cu but E is far greater the E Cu CPVC

L and L are similar CPVC Cu

Thermal Expansion = e = Lp . C . D T

Length of pipe in expansion loop = L = 3 E Do e

Where: e = Thermal expansion Lp = Length of pipe in total C = Coefficient of thermal expansion DT = Temperature change L = Length of pipe in expansion loop E = Young’s modulus, modulus of elasticity Do = Outside diameter of pipe S = Hydrostatic design stress

2S

½


Expansion loops - CEN proposals

DL = DT . L . a

BA (bending arm) = C (Do . DL)

CPVC PP

a 0.07 0.15

C 34 30

e.g for DT = 50° C

L = 20m

Do = 25mm

CPVC PP

DL = 70mm 150mm

BA = 1.42 m 1.84 m

½


CPVC piping in walls

Allow to expand freely or embed in concrete. Concrete should be homogeneous, without gravel or stones which risk damaging the pipe.

Do not embed demountable fittings.

Pressure testing should be done before concrete is poured.

CPVC pipe running through concrete block


CPVC piping in walls

As pipe thermally expands tensile stresses will be developed. Concrete will contain the CPVC. Other materials may not, e.g plasterboard. The developed tensile stress, s , is given by the

equation: s = C . DT . E

C = Coefficient of thermal expansion

DT = Temperature change

E = Youngs modulus

This calculated developed tensile stress may be compared to the tensile strength of the surrounding material (plasterboard, concrete, etc.) to give an indication whether material will contain the pipe, or whether the pipe will crack the wall. For CPVC : C = 6.1 x 10-5 cm/cm°C

E = 2650 MPa


CPVC Installations in Concrete

FlowGuard™ CPVC pipe and fittings are acceptable for use in embedded concrete. Direct contact with concrete does not have any adverse effect on FlowGuard™ materials. Typical recommended installation practices should be followed. In addition, particular care must be paid to the following guidelines:

1. As the FlowGuard™ pipe is laid out be certain that it does not come in contact with sharp objects or edges, such as rocks, metal, or structural members.

2. Straight runs of pipe will minimise the stress on the pipe.



3. Avoid the contact of FlowGuard™ pipe and fittings with construction materials that are incompatible with CPVC. Verify the suitability of a particular product for use with CPVC with the manufacturer of the particular construction material. 4. Steps must be taken to prevent the wire mesh or reinforcing bars from causing any abrasion damage to the FlowGuard™ pipe and fittings. This is mostly of concern prior to pouring the concrete.

Example of vertical runs of FlowGuard™ pipe prior to pouring concrete



5. When there are pipe joints that will eventually be covered in concrete, the installation must be pressure tested prior to pouring the concrete. If there will be no joints covered by concrete, there is no need to pressure test prior to pouring the concrete.

6. Prior to the pouring of the concrete, the FlowGuard™ pipe should be intermittently secured to prevent movement during this process. Nonabrasive, plastic fasteners are good choices for this application.



7. Care should be taken so that the pipe and fittings are not damaged by the tools and equipment used to pour and finish the concrete.

FlowGuard pipe while pouring concrete

8. As the concrete is poured, periodically check to see that the pipe has not moved from its intended positioning.



9. During the concrete pouring process jostle the pipe periodically to assure that there are no air pockets around the pipe. The pipe should be fully covered in concrete. There is a possibility of abrading the pipe if large air pockets are permitted to form around the pipe. 10. Thermal expansion and contraction is not an issue for FlowGuard™ pipe and fittings that are embedded in concrete. Those forces are relieved in a manner that does not affect the pipe or fittings. However, expansion and contraction must still be incorporated in the design of those sections of pipe that are not embedded in concrete. Failure to adequately allow for stress at these points may result in damage to the pipe where it enters and exits the concrete. 11. Pipes may be sleeved at entry and exit points to provide extra protection, but if care is taken to avoid damage during application & finishing of the concrete, this should not normally be necessary.


Thermal Insulation CPVC has a much lower thermal conductivity than metals used in piping systems (0.14 W/mK for CPVC versus >400 W/mK for copper). For this reason in most cases it is not necessary to thermally insulate CPVC piping. However the equation below can be used to calculate the approximate heat loss from CPVC pipes per 1 meter length of pipe.

Q/L = 2 . P . l . DT

Ln (do/di) (1)

Where :

Q/L = Heat loss per peter of pipe, W/m

l = Thermal conductivity, (W/mK) for CPVC, l = 0.14 W/mK

P = 3,1416

di = Inside diameter, mm

do = Outside diameter, mm

DT = Temperature differential between inner and outer surface of pipe.

This can be approximated to : T water - T ambient (K)

In fact, the outside pipe surface temperature is significantly different to T ambient. However, this will be ignored to facilitate comparison between

CPVC and other materials.


Thermal Insulation

= 185 W/m

Example :

What is the heat loss/meter from a 20 mm outside diameter CPVC pipe,

wall thickness 2.3 mm, with water flowing inside at 80°C and an

ambient air temperature of 25°C?

Q/L = 2 . 3,1416 . 0,14. (80-25)

Ln (20/15.4)

Equation (1) can be simplified for standard pipe dimensions to :

Q/L = K . DT (2)

where K is a coefficient taking into account the thermal conductivity of

CPVC and the pipe geometry. In the previous example, do = 20 mm,

di = 15.4 mm

K = 2 . 3,1416 . 0,14

Ln (20/15.4) = 3.37 W/mKs


Thermal Insulation K has been calculated below for ASTM Schedule 80 (F441)

CPVC pipe

ASTM Schedule 80 Nom. diameter K value (W/mKs) 1/2 2.04 3/4 2.54 1 2.77 1¼ 3.37 1½ 3.72 2 4.33 2½ 4.12 3 4.68 3½ 5.08 4 5.42 6 6.30

Example for 1½ " :

K = 2 . 3,1416 . 0,14

Ln (48.3/38.14)

K = 3.72 W/mKs

Example :

What is the heat loss/meter for a 2 inch ASTM Schedule 80 CPVC pipe,

with a temperature differential of 60°C?

Q/L = 4.33 x 60 = 260 W/m


Thermal Insulation

K has been calculated below for DIN 8079 CPVC pipe

(PN 16, 20 and 25)

DIN 8079 Outside K value (W/mKs)

Diameter

PN16 PN20 PN25

(S = 6.25) (S = 5) (S = 4)

SDR 13.5 SDR 11 SDR 9

16 - 160 5.5 4.4 3.5


Scale build up Function of roughness of pipe, as measured by Hazen-Williams

’C' factor used in Hazen-Williams formula for calculating friction

head losses in piping systems.

Higher value for C - less friction

- less head loss

Material C Factors

New After 4-40 years service

CPVC 150 150

Copper/Steel 130 -140 60 -120

Once corrosion attack starts (e.g. green colour from copper

reacting with chlorides in water to form copper chloride),

this starts a vicious circle leading to scale build up.

With CPVC, there is no corrosion and hence scale build up is inhibited.

Steel

Copper


Condensation

CPVC versus Copper

- For a given ambient air temperature and water temperature in the pipe, the relative humidity must be 10 to 15 % higher with CPVC to get the same degree of condensation . or - For the same humidity level and water temperature, the external air temperature can be ± 10°C higher than for copper to get the same degree of condensation.


CPVC and chilled water systems (1 of 2)

FlowGuard™ CPVC pipe and fittings are acceptable for use with chilled water provided that the water stays above freezing point.

Particular care must be paid when other fluids or agents are used or added to the water:

1. Heat transfer fluids : Ethylene glycol, propylene glycol and glycerine: see Lubrizol published recommendations. For other products - please ask your Lubrizol representative.

2. Anti-corrosion agents may be used to protect the chiller system from corrosion. In general, corrosion inhibitors at their ordinary use concentrations are not detrimental to CPVC but please ask your Lubrizol representative for confirmation.


CPVC and chilled water systems (2 of 2)

Heat exchanger system: should be flushed out before connecting to CPVC piping. (The heat exchanger coil may have on its surface some metal forming oils or other types of lubricants left over from the manufacturing process. Certain of these lubricants may be detrimental to CPVC and therefore need removing.)

The refrigerant: is used in combination with an oil component in the compressor side of the chiller to provide cooling. As long as the heat exchanger coil remains intact, the refrigerant and associated oil should not come in contact with the CPVC piping. If the heat exchanger coil ruptures, the refrigerant and its associated oil may leak into the CPVC recirculating piping. Some types of refrigerant oils used may lead to failures of the CPVC re-circulating piping ( e.g. POE oils can be highly detrimental). Proper operation conditions and preventive maintenance of the chiller system can prevent such a rupture.


Quieter than copper Velocity of sound in :

CPVC = 1350 M/S

COPPER = 3600 M/S

WATER = 1473 M/S

Based on classical approach (Newton) using Youngs modulus:

VELOCITY = (YOUNGS MODULUS/DENSITY) 1/2

This means that in a :

Copper System : Sound travels in the copper

CPVC System : Sound travels in the water and system is as quiet as physically possible.


Water Hammer

Pressure surge resulting from instant change in velocity of the flowing water

Governing equation is a modified version of Newton’s speed of sound equation

(velocity of propagation of elastic vibration)

VELOCITY = (YOUNGS MODULUS / DENSITY) 1/2

" The maximum theoretical shockwave for both CPVC and Polybutylene is much lower than the values for copper tubing. This is easily understood when it is recognized that the modulus of elasticity for the plastic piping material is much lower than the modulus of elasticity for copper."

Source: JB ENGINEERING AND CODE CONSULTING, P.C., Munster, IN, Water hammer control in small systems , October 18 , 1994

flowguard vs ppr presentation 2014 - alwaab plastics

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