High Density Polyethylene Pressure Pipe

High density polyethylene pipe has been used extensively around the world since the 1950’s. The unique properties of High density polyethylene pipe have offered an alternative to traditional material like steel and copper and also in non pressure applications where clay and fibre cement pipes were used.

The material has been developed internationally from PE 80 to today’s PE100 material which has shown a saving of approximately 30% on the wall thickness from the early days of Polyethylene. This mass saving relates back to a cost saving and a better performance as the internal diameter of the pipe is better. In many cases, because of the excellent flow characteristics of Polyethylene, pipes could be down sized while still performing within the expected parameters.

The pipes’ properties such as impact resistance and resistance to abrasion have made HDPE pipe the obvious choice in the mining and Industrial markets.

Piping made from polyethylene is a cost effective solution for a broad range of piping applications in the municipal, industrial, marine, mining, landfill, duct and agricultural industries. It has been tested and proven effective for above ground, surfaced, buried slip-lined, floating and subsurface marine applications.

High-density polyethylene (HDPE) pipe can carry potable water, waste water, slurries, chemicals, hazardous wastes, and compressed gasses. In fact, polyethylene pipe has a long and distinguished history of service in the gas, oil, mining and other industries. It has the lowest repair frequency per kilometer of pipe per year compared with all other pipe materials used for urban gas distribution.

Polyethylene is a strong, extremely tough, very durable product which offers long service and trouble-free installation.

Applications

High density Polyethylene pressure pipes are specified with confidence in the following applications:

• Civil Engineering. Water mains and reticulation systems
• Building. house connections and cold water reticulation systems
• Agriculture. Irrigation and water supply schemes
• Industrial. Sewer effluent control and water purification. Conveyance of chemicals and water in most industrial plants.
• Mining. Conveyance of water and air in underground operations. Used extensively in treatment and recovery plants.

HDPE is generally used for high pressure applications ranging from 3.2 to 25 Bar, in conjunction with compression, butt-weld or Electrofusion fittings. HDPE piping conforms to the SABS ISO 4424:1996 specifications.

Quality

HDPE pipe is manufactured to the relevant SABS and international quality specifications.

Characteristics of HDPE pipe

HDPE Material

Polyethylene pressure pipe systems offer many advantages when compared to traditional products, namely:

• Weather resistance in above ground applications
• Highly corrosion resistant
• Ease of handling and installation, exceptional toughness
• Excellent abrasion resistance
• Manufactured long lengths and coils
• Manufactured to internationally accepted standards
• Service performance in excess of 50 years

Resistance to weather degradation

The high percentage of carbon black in the formulation of the pipe raw material enables HDPE pipe to resist degradation by ultraviolet rays. The pipe is impervious to rain and wind conditions.

Chemical resistance

HDPE Pipes are chemically inert but there are some chemicals could affect the pipe. As the product is also not electrically conductive, reactions cannot take place within the pipe and affect its performance.

HDPE has excellent corrosion resistance and is virtually inert so it does not need expensive cathodic protection. It offers better resistance to corrosive acids, bases, and salts than most piping materials and also has good resistance to many organic substances such as solvents and fuels.

Natural soil chemicals cannot degrade the pipe in any way.

Ease of Handling

Conventional materials are much heavier than HDPE and will require cranes and lifting gear. Handling of the product can often be done by hand allowing ease of installation in confined spaces and difficult terrain.

High Strength and flexibility

HDPE material has a high degree of impact resistance and is robust and ductile. Pipes can bend quite easily allowing for savings in design as less critical angle changes can be made without bends. HDPE pipe can be laid across uneven surfaces and in narrow trenches. Pipe can be joined outside of the trench before installation into the trench. The ability to absorb pressure surges makes the product superior to other plastic pipe materials.

Even in sub zero temperatures HDPE can still perform to expectation.

Resistance to abrasion

Where very abrasive mediums have to be transported HDPE has proved itself to be the pipe product of choice. HDPE outperforms traditional pipe materials such as steel and steel with sacrificial layers (rubber lined steel).

The product is used extensively in mine tailings and washing plants.

Co-efficient of friction

The smooth internal surface of the pipe and the impermeability of HDPE allows a greater flow capacity and minimal Friction loss. It has less drag and a lower tendency for turbulence at high velocity. Its superior chemical resistance and non-stick surface combines to eliminate scaling and pitting. This preserves the excellent hydraulic characteristics throughout the pipe’s service life.

When designing pipelines, use the Hazen-Williams C factor of 150 and an n Factor of 0.009, when using the Manning formula.

Polypropylene Pipe

• Polypropylene sizes 20mm to 500mm
• Available in material grade PPH-100 & beta pp as per DIN 8077
• Also available as coils from 20mm to 110mm diameter

Applications and uses:

Polypropylene is one of the most common, fastest growing and versatile thermoplastics currently used. Each year
many tons of this material are converted into diverse products ranging from plastic bags through automobile parts
to tanks and chemical piping systems

Waste

Over a period of many years, polypropylene has become a preferred material for handling many different types of liquid waste. This material’s wide range of chemical resistance makes it very suitable for handling the wide range of different chemicals and mixtures that are found in different waste streams. The unsuitability of polypropylene for use with concentrated oxidizing acids is generally not a problem because these acids will usually be diluted before they are disposed of. The high resistance of polypropylene to solvents is particularly important, because many solvents do not mix in water and often end up floating in a concentrated form near the top of the pipe. Thus, even though a waste stream may contain only 1% of a solvent, it is often not possible to regard this dilution because most of the solvent will often float to the top of the pipe. The material’s high temperature capabilities are also important in enabling it to handle any exothermic reactions that may occur when different chemicals mix.

Deionized Water

Large volumes of distilled or deionized water are used by a wide range of different industries. This water is often used for diluting chemicals, washing and rinsing. Polypropylene is commonly used as a piping material for conveying this water. Polypropylene piping systems are able to maintain the purity required in all but the most demanding installations. Fusion joining gives fast reliable joining without the use of hazardous and noxious solvents that may contaminate the water. The total quantity of added lubricants and organic materials in polypropylene is far less than found in many other plastic piping materials. The use of

A pigmented material is recommended to reduce degradation of the pipe material from ultraviolet light. The pigmented pipe wall will prevent the transmission of ambient light into the pipe material. This prevents possible degradation of the pipe wall and corresponding particulation of plastic into the water stream.

Caustic Solutions

The chemical resistance of polypropylene to caustic solutions such as potassium hydroxide and sodium hydroxide is very good. The fusion joining method gives strong joints that are resistant to attack by these strongly caustic solutions. This contrasts to solvent cemented joints which may be attacked by some caustic solutions. For these reasons polypropylene is often used to transport caustic soda used for neutralizing acidic waste streams.

PPH pipes are produced as per DIN 8077 table given below.

Colour RAL 7032 – beige grey / pebble grey.

DN	NOMINAL PRESSURE										DN
	PN 2.5		PN 4		PN 6		PN 10		PN 16
de mm	e mm	dl mm	e mm	dl mm	e mm	dl mm	e mm	dl mm	e mm	dl mm	de mm
20					1.8	16.4	1.9	16.2	2.8	14.4	20
25					1.8	21.4	2.3	20.4	3.5	18.0	25
32					1.9	28.2	3.0	26.0	4.5	23.0	32
40					2.3	35.4	3.7	32.6	5.6	28.8	40
50	1.8	46.4	2.0	42.4	2.9	36.6	4.6	37.2	6.9	36.2	50
63	1.8	59.4	2.5	54.4	3.6	47.2	5.8	47.8	8.7	45.6	63
75	1.9	71.2	2.9	65.4	4.3	56.8	6.9	57.4	10.4	54.2	75
90	2.2	85.6	3.5	78.6	5.1	68.4	8.2	69.2	12.5	65.0	90
110	2.7	104.6	4.3	96.0	6.3	83.4	10.0	84.6	15.2	79.6	110
125	3.1	118.8	4.9	109.0	7.1	94.8	11.4	96.0	17.2	90.6	125
140	3.5	133.0	5.4	122.2	8.0	106.2	12.8	107.4	19.4	101.2	140
160	3.9	152.2	6.2	139.8	9.1	141.8	14.6	123.0	22.1	115.8	160
180	4.4	171.2	7.0	157.2	10.2	136.8	16.4	138.4	24.9	130.2	180
200	4.9	190.2	7.7	174.8	11.4	152.0	18.2	153.8			200
225	5.5	214.0	8.7	196.6	12.8	171.0	20.5	173.0			225
250	6.1	237.8	9.7	218.4	14.2	190.0	22.8	192.2			250
280	6.9	266.2	10.8	244.6	15.9	212.8	25.5	215.2			280
315	7.7	299.6	12.2	275.2	17.9	239.4	28.7	242.2			315

Physical Properties

Polypropylene Property	Value	Unit	Standard
Density	0.912	gm / cm 3	ISO 1183
Tensile Creep Modulus 1 hr ( 1.5 N/mm2 )	740	N / mm2	ISO 899
Tensile Creep Modulus 1000 hr ( 1.5 N/mm2 )	320	N / mm2	ISO 899
Modulus of Elasticity	950	N / mm2	ISO 527
Izod Impact Strength, 0º C	150	K J . m2	ISO 180 / 1C
Vikat Softening Point – 5kg	145	º Celcius	ISO 306
Flammability ( oxygen index )	17.5
Max Service Temperature	100	º Celsius
Thermal Conductivity	0. 22	W . m . K	DIN 52612
Linear Coefficient Of Thermal Expansion	15 x 10 -5	K -1	DIN 53752
Volume Resistivity	> 10 15	Ohms . cm	IEC 93
Surface Resistance	> 10 14	Ohms	IEC 93

PVDF (Polyvinylidene Fluoride) Pipe

Polyvinylidene fluoride, or PVDF, is a fluorinated thermoplastic which has outstanding resistance to most mineral and organic acids, aliphatic and aromatic hydrocarbons, alcohols, halogenated solvents, and oxidizing environments. It also has outstanding aging resistance, with its properties remaining constant after many years of continuous use.

Typical Values

Physical Properties	ASTM Test Method	Units	PVDF
Density	D792	lbs/in3	0.064
Water absorption: 24 hrs, 73° F	D570	%	<0.4

Mechanical Properties	ASTM Test Method	Units	PVDF
Tensile Strength, Ultimate, 73°F	D638	psi	30,2006,650
Tensile Modulus, 1% Secant, 73°F	D638	psi	348,000
Elongation, ultimate, 73° F	D638	%	80
Flexural Strength, 73° F	D790	psi	10,750
Flexural Modulus, Tangent, 73°F	D790	psi	391,500
Compressive Strength, 73°F	D695	psi	11,600
Izod Impact Strength, Notched, 73°F	D256	ft-lbs/in.	1.9
Rockwell Hardness	D785	—-	R100
Coefficient of friction @ 68°F, 1200 in/min, 155 lbs. Load	—-	Static/Dynamic	0.3

Thermal Properties	ASTM Test Method	Units	PVDF
Heat Deflection @ 264 psi,	D648	°F	235
Coefficient of Linear Thermal Expansion	D696	in./in./-°F	7.1 X 10-5
Melting Point	D3448	°F	352
Thermal Conductivity	C177	BTU-in/hr-ft2/°F	1.31
Flammability	UL94	—-	V-0

Electrical Properties	ASTM Test Method	Units	PVDF
Volume Resistivity, 73°F	D257	ohm-cm	5 X1014
Dielectric Constant @ 60 Hz, 73°F	D150	—-	9

ABS (Acrylonitrile Butadiene Styrene) Pipe

ABS (Acrylonitrile Butadiene Styrene) is highly rated as a thermoplastic pipework system and is used in many applications such as food and beverage processing as well as water and sewerage treatment and many other industries.

ABS has good chemical resistance with high impact strength. ABS is non toxic and conforms to the toxicological requirements of the British Plastic Federation, British Industrial Biological Research Association Code of Practice for food usage 45/5.

It also fulfils the EEC requirements for plastic materials in contact with foodstuffs. ABS systems are lightweight, rigid and easy to install using a solvent cement.

WRAS Approval

Water Regulations Advisory Scheme – approved product for potable water.

Standards

Individual products are in compliance with appropriate British Standards.
Kitemark Licence No. KM 60042

Fittings (inch size)	BS 5392 Part 1
Pipe (inch size)	BS 5391 Part 1
Fittings (mm size)	DIN 8063, KIWA 549, ISO
Pipe (mm size)	DIN 16890, DIN 16891
Threaded fittings	BS 21, DIN 2999, ISO 727

Chemical Resistance

ABS has good resistance to most diluted inorganic acids, salts, animal fats and oils and organic acids. It is not resistant to organic solvents, alcohol, petrol, acetic acid or vegetable oils. Recommendations can be given by our Technical Department regarding the resistance of ABS to specific chemicals.

Temperature & Pressure Relationship

Temp °C	Class C	Class D	Class E
	bar	bar	bar
-40	9.0	12.0	15.0
-20	9.0	12.0	15.0
0	9.0	12.0	15.0
20	9.0	12.0	15.0
30	7.5	10.0	12.5
40	6.1	8.1	10.1
50	4.6	6.1	7.7
60	2.7	3.8	4.5
70	1.8	2.4	3.0
80	0.6	0.7	0.9

Pressure Ratings Fittings & Valves

Product	Size Inches	Pressure Rating
Fitting Solvent Cement	½ – 4	15 bar (217psi)
	5-6	12 bar (173psi)
	12½ & 8	9 bar (130psi)
Valves	⅜ – 2	16 bar (232psi)
Valves	2½ – 4	10 bar (145psi)

All pressure ratings are at 20°C

Temperature and Pressure

It is suitable for use over a wide temperature range from -40°C to +80°C at pressures up to 15 bar.
Please consult the above temperature/pressure relationship chart for specific ratings.
It is important to remember that if the temperature is increased above 20°C then the pressure must be reduced.

ABS in sub-zero temperatures

ABS Pipe systems are suitable for temperatures as low as -40°C, however it is necessary as with any other pipeline to take preventative measures to ensure the pipeline fluid does not freeze, as freezing would cause subsequent damage to the system.

Thermal Expansion

The thermal coefficient of linear expansion for ABS is 10.1 x 10-5/°C.
It is necessary in certain situations to make special provision for this expansion and contraction.
Thermal expansion of ABS is compared with other materials, in the following chart.

Polybeutylene Lined Pipe

This specialized pipe is PE100 with an internal epoxied layer of Polybeutylene suited for petrochemical applications such as petrol station forecourts.