| Sr No . | Criteria | HDPE PIPE | DI PIPE/ MS pipe/Bar wrapped steel cylindrical pipe (BWSC) |
| 1 | Pipe performance | Pipe line Efficiency do not detoriates with time. | Pipe line Efficiency detoriates with time. |
| 2 | Dependabilityfor Pipe performance and Chemical resistance. | Not Dependant on other material. All properties are inherent properties of HDPE pipe. | In case of Metal pipe over all performance depend on other material and it’s quality. A) External corrosion is depend on Quality and damange of Metallic zinc & Bituminous paint’s used for extrenal protection. B) “C” value, chemical resistance depend on- Cement Mortar C) Quality of CM and epoxy lining is dependant on -Type & quality of cement or epoxy. D) Cement Mortar lining may fail due to (-ve)surge pr.; due to Disbonding ; due to Deflection of pipe ; due to Cracks in CM or due to Diff. Tempreture. I) – Socket do not have protection by cement Mortar |
| 3 | Is there any surface in pipe line which is not protected ? | Through out the length pipe satisfy the requirment. Internal surface charecterisics is same through out the length. It’s Chemical resistance is same at all locations. | Inside the Socket, surface is not protected by cement Mortar linning. Hence corrosin may start here and result in improper seat for rubber ring i.e in leakage, contamination of water, pitting in pipe etc. Internal surface charecterisics is not same through out the length i.e.in barrel, socket and for rubber ring. It’s Chemical resistance is not same at all locations. |
| 4 | Earthquake effect | The flexibility and strong joint makes HDPE pipe it well suited for dynamic soils including areas prone to earthquake. | May have major leakage problem after earthequake |
| 5 | Surge Pressure | HDPE pressure pipe will produce very low surge pressure . Surge pressure is about 20% than that of Metal Pipe. HDPE pressure pipe can accept repetitive pressure surges.Can withstand for all pressure up to 2.3 times rated pressure | We can say Surge pressure is 5 times of HDPE pipe Surge pressure. Need surge protection instruments. can accept limited repetitive pressure surges.Can withstand for all pressure up to 1.5 times rated pressure |
| 6 | Surge Pressure protection device / Concrete-Thrust block. | Not required. | Required |
| 7 | Suitability in BC soil, against Soil Movement/ soil Settlement | HDPE takes care for soil movement and settelmentofsoil,suitableinBC&expansivesoil also. | Very limited settelment/ movment will tolrate. Not suitable in BC & expansive soil also. Needs Lot of care in these situations. |
| 8 | Corrosion, holes in pipes etc. | Not possible due to its excellent material properties. | Major problem due to it’s material properties. |
| 9 | Infiltrationproblems | HDPE pipe’s fused joints simply do not leak, eliminating infiltration problems. | Experienced Infiltration with almost every scheme |
| 10 | Chemical Resistance | HDPE pipe has superb chemical resistance and is the material of choice in harsh chemical environments | Limited resistance. |
| 11 | Joint Type | Heat Fusion Joint- Mostly used, Other types of joints are Electrofusion joint, Flange Joint. | Rubber Ring Joint. Or welding |
| 12 | Joint Strength | Joint is as Strong as Pipe Material | Joint is much more Weak than Pipe Material |
| 13 | Joint Leakages | Joints are almost Zero % Leak. | All over world it is accepted that leakages are min 25% and max up to 75%. |
| 14 | Joint Leakages Location | No leakage in Length | Everyjointispotentialpointforleakages.i.eatevery10to20feet. |
| 15 | Joint performance with Tempreture. | Joint performance not depend on temperature of water and quality of any other material. If pipe is subjected to continuous temp. more than 300C needs derating in pipe pressure. Normally pipe specs are deigned for water temp.of 300C. | Joint performance depend on temperature of water. Since lot of manufacturer reccomends that store Rubber Ring bellow 25degree C temp.Means if water temp. is above 250C then performance will affect. Performance is depend on Quality of Rubber ring. Means if temp is more than 250C then joint performance will not be up to mark and this is one of the main reason for leakages. |
| 16 | Bending of pipes. | Because of excellent joint pipe can bend with rediusupto 25 times its dia. | Only 1to 2 degree deflection possible. Means almost negligible and hence bends are required at each change in direction.. |
| 17 | Efficient life and Life Cycle Cost – with respect to pipe material cost only | 100 years : The Life Cycle Cost of HDPE pipe is zero. | 35 years : For 100 years Assuming 35 years as a efficient life of pipe.The Life Cycle Cost of it is more than 62 times of its original cost. |
| 18 | Ease to work. | Thecombinationofflexibilityandleakfreejoints allow for unique and cost effective types of installation methods. Such as we can do the welding & testing of max. length of pipes on ground and then just push the pipes in a trench. Ease to installed in water logged area, river crossing, sea out falletc. | Dueto rigidity and rubber ring joint installation has to done in trench. Installed in water logged area, river crossing, sea out fall etc is not possible. |
| 19 | Hazen William’s “C” Factor | 150 – Through out the life span i.e.>100 years | 120 with CM lining,but may come down to 70 to 90 after 35 years. Resulting in to more pumping cost or less discharge |
