Surpass Polypropylene Limitations with Reliable FlowGuard CPVC

Transcription

1 Surpass Polypropylene Limitations with Reliable FlowGuard CPVC 1

2 FlowGuard CPVC advantages over PPR Excellent Physical Properties Better Antimicrobial Performance Superior Installation Eco Friendly UV Resistant Long Term Performance Chlorine Resistant Easy Repairs Fire Resistant Quality Assured 2

3 CPVC vs PPR - Physical Properties Tensile Strength (Mpa at 23 C) Coefficient of Thermal Expansion (x10-4 K -1 ) Thermal Conductivity (W/MK) Oxygen Permeation (cm³/m.day.atmosphere) at 70 C CPVC PPR <1 insignificant 13 CPVC: : - Needs less hangers and supports - No looping of the pipe - Higher pressure bearing capability, same flow rate with smaller pipe size Sources: Saechtling Intl. Plastics Handbook, Modern Plastics Encyclopedia, Chemical engineers Handbook, British Gas 3

4 CPVC vs PPR - Physical Properties CPVC PPR CPVC: - Straight professional appearance - Need less hangers and supports - Less looping 4

5 CPVC vs PPR - Physical Properties CPVC PPR CPVC: - Suitable for vertical risers 5

6 CPVC vs PPR - Physical Properties WALL THICKNESS PN 20 PIPE Wall thickness (mm) Outside Diameter (mm) CPVC PP PEX PB PN20, 20mm Wall thickness: CPVC : 1.9 mm PP: 3.4 mm Source : DIN 8077/8079/16969/16893 CPVC: : Has a higher pressure bearing capability. This leads to same flow rate with smaller pipe size 6

7 Installation Techniques CPVC: Solvent Welding Tools required are simple and cheap. Only tools required: 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. CPVC SOLVENT CEMENT No need for electrical source. 7

8 Installation Techniques CPVC: Solvent Cement Mechanism Plastic Fitting Plastic Fitting Cement Plastic Pipe Plastic Pipe Cohesive bond formed 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. 8

9 Installation Techniques PPR: Fusion : - Welding 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. Welding machine/tools for larger sizes 9

10 Installation Techniques 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 10

11 Installation Techniques PPR : Fusion Welding 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. 11

12 CPVC vs PPR - UV Resistance CPVC : : PPR : : - - The main degradation process is dehydrochlorination, not oxidation. - U.V. acts as a strong catalyst for the oxidation process which breaks down polymer chain, - 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. leading to weakness in pipe and loss of hydrostatic strength. - There is a loss of impact resistance due to impact modifiers losing efficiency. This may even result in increased modulus. 12

13 CPVC vs PPR - UV Resistance CPVC study : Natural Weathering Effects on some properties of CPVC material - 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

14 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. CPVC: 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. PPR: 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. 14

15 CPVC / PPR and Chlorine CPVC: Access to the CPVC carbon chain is restricted by the chlorine on the molecule Chlorine Hydrogen Any chlorine which actually reaches the backbone, simply chlorinates it further. The effect is the same as the resin chlorination process.... Carbon... 15

16 CPVC / PPR and Chlorine PPR: Hypochlorous acid attack on polypropylene Bonds are broken at tertiary carbon sites Hydrogen Chlorine Hydrogen Chlorine Carbon Oxygen Carbon Oxygen 16

17 CPVC / PPR and Chlorine This effect has been seen in practical situations Temperature/ Pressure Relief Valve Electric Heating Elements Thermostat HOT COLD OUT IN Anode Rod DIP TUBE Steel Tank Insulation Outer Case Drain Valve 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. 17

18 CPVC / PPR and Chlorine And studied by many leading test labs 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 18

19 Chlorine resistance testing Results & experiences from tests on polyolefin pipes exposed to chlorinated water Material ( Specimen ) Hoop Stress ( Mpa ) Chlorine Concentr. ( ppm) Failure Time ( hours ) Relative Failure Time PO A PO A PO A PO A PO B PO B PO B PO B PO C PO C PO C PO - C Source: Studsvik Polymer AB Sweden / Tokyo Gas Co., Ltd. Japan ( presented at the Plastic Pipes X Conference 1998 ) 19

20 Increasing Testing Severity Chlorine resistance testing NSF P171 Protocol Two End-Use Conditions: Continuous re-circulation (Cl-R) 100% at 60 o C 4 ppm chlorine, 6.8 ph Minimum extrapolation is 80 years with no safety factor Traditional domestic (Cl-TD) 25% at 60 o C, 75% at 23 o C 4 ppm chlorine, 6.8 ph Minimum extrapolation is 80 years with no safety factor 20

21 Chlorine resistance testing PPR testing PPR Manufacturer A PPR Manufacturer A Before After Tested in general accordance with NSF P-171 Protocol for Chlorine Resistance of Plastic Piping Materials and ASTM F 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 21

22 Chlorine resistance testing 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. 22

23 CPVC / PPR and Chlorine Warning letter from Plastics Industry Pipe Association in Australia - premature aging of polyolefin pipes are causing concerns! 23

24 CPVC / PPR and Chlorine 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 24

25 Fire Related properties Limiting Oxygen Index (% of Oxygen needed in an atmosphere to support combustion) CPVC PPR 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: - Low flame spread and smoke generation - Self extinguishing - No flaming drips 25

26 CPVC and Fire Resistance Testing EN :2002 Fire classification of construction products and building elements CPVC rating = B s1 d0 Fire behavior Smoke development Flaming droplets B Low flammability, no contribution to flashover s1 Low smoke development d0 No burning drops The best possible rating a non-metal material can receive 26

27 CPVC vs PPR: Antimicrobial Performance Dr. Paul Sturman concludes: CPVC consistently outperforms most other nonmetallic piping materials with regard to its ability to resist the formation of biofilms. 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 Source: Assessment of the Microbial Growth Potential of Materials in Contact with Treated Water Intended for Human Consumption, KIWA,

28 pg ATP/cm² CPVC vsppr: Antimicrobial Performance Study conducted by CRECEP in France, confirm the ability of CPVC to resist biofilm formation Comparison of BPP (Biomass Production Potential) values* observed at 30 C and 50 C BPP at 30 C BPP at 50 C Copper CPVC Inox 304 Inox 316 Polybutene Polypropylene (Inox 304/316 = Stainless Steel ) * Values measured at 8, 12 and 16 weeks 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

29 CPVC vs PPR: Antimicrobial Performance In the presence of the two CPVC materials, the growth of Legionnella bacteria in the water was low Study: Biofilm Formation Potential of Pipe Materials in internal installations by H.R. Veenendaal / D. van de Kooiy KIWA (KIWA is the approvals agency for potable water piping systems in The Netherlands) 29

30 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,

31 CPVC vs PPR: Recycling CPVC : : PPR : : - 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. Cannot meet the strength and performance requirements of many applications without fiberglass reinforcement More expensive and not recyclable due to its fiberglass layer 31

32 Hoop Stress (MPa) Hydrostatic stress, in Mpa CPVC vs PPR: Long term performance LTHS Performance at 95 C Reference curves for expected strength at 95 C 10 CPVC PPR PPR CPVC Time (hours) Time to fracture, in hours Source: EN ISO / EN ISO

33 CPVC vs PPR: Repairs CPVC : : PPR : : - On line repairs - punctures could On line repairs In case of be repaired like a patch made punctures, one has to cut open a from section of a pipe and solvent pipe line and repairs are done cemented in situ without with the socket dismantling the pipe If any additional fitting of higher Similarly, if any additional fitting diameter needs to be added or needs to be added or replaced, it replaced, the pipe line has to be is easy. dismantled due to heavy tooling Training to plumbers : Lubrizol as needed for heat fusion, or one raw material supplier and our has to use electro fusion fittings FlowGuard licensees train the which are expensive plumbers 33

34 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 34

35 CPVC: Quality Assurance CPVC: : 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 The globally established FlowGuard brand assures quality! 35

36 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 36

37 Thermal expansion and Contraction 37

38 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) 38

39 Thermal expansion and Contraction 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) 2L/5 (12" or 32 cm) L/2 (16" or 40 cm) L (31" or 79 cm) 6" min. 6" min. L/4 LOOP OFFSET CHANGE IN DIRECTION Do not butt up against fixed structures (joist, stud, wall) 39

40 Thermal expansion and Contraction Example of loop allowing thermal expansion 2014 The Lubrizol Corporation, all rights reserved. All marks are property of The Lubrizol Corporation, 40 a Berkshire Hathaway Company. 40

41 Expansion loop requirements Thermal Expansion = e = Lp. C. D T Length of pipe in expansion loop = L = 3 E Do e ½ 2S 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 C CPVC is greater than C Cu but E Cu is far greater the E CPVC L and L are similar CPVC Cu 41

42 Expansion loops - CEN proposals DL = DT. L. a BA (bending arm) = C (Do. DL) ½ e.g for DT = 50 C L = 20m Do = 25mm CPVC PP a C CPVC PP DL = 70mm 150mm BA = 1.42 m 1.84 m 42

43 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 43

44 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 44

45 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. 45

46 CPVC Installations in Concrete 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 46

47 CPVC Installations in 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. 47

48 CPVC Installations in Concrete 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. 8. As the concrete is poured, periodically check to see that the pipe has not moved from its intended positioning. FlowGuard pipe while pouring concrete 48

49 CPVC Installations in Concrete 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. 49

50 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) 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. (1) 50

51 Thermal Insulation 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, ,14. (80-25) Ln (20/15.4) = 185 W/m 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, ,14 Ln (20/15.4) = 3.37 W/mKs 51

52 Thermal Insulation K has been calculated below for ASTM Schedule 80 (F441) CPVC pipe ASTM Schedule 80 Nom. diameter K value (W/mKs) 1/ / ¼ ½ ½ ½ Example for 1½ " : 2. 3, ,14 K = 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 52

53 Thermal Insulation K has been calculated below for DIN 8079 CPVC pipe (PN 16, 20 and 25) DIN 8079 Outside Diameter K value (W/mKs) PN16 PN20 PN25 (S = 6.25) (S = 5) (S = 4) SDR 13.5 SDR 11 SDR

54 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 Material New - less friction - less head loss C Factors After 4-40 years service CPVC Copper/Steel Steel 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. Copper 54

55 Condensation - 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 versus Copper 55

56 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. 56

57 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. 57

58 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. 58

59 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,