Woodford Plastics - Process Pipework
We install, test, repair and modify process pipework in the Chemical, Pharmaceutical, Nuclear, Glass, Pulp & Paper and a wide range of other industries which require chemical and acid resistant pipework.
The market supplies a wide range of pipe systems manufactured for a number of different plastics, ensuring that there are systems available for a wide range of aggresive process's.
Examples of different types of plastics used in pipe systems are detailed below;
Generaly used in less aggresive environments such as water distribution, sewerage and waste water applications due to PVC-U's biological and chemical resistance, light weight, high strength and low cost were corrosion which would limit the use of most metals.
This is a chlorinated version of PVC-U. It has a higher operating temperature and as such can be used in hot and cold water systems wereby its relatively good chemical resistance will make it a better choice than copper. PVC-C also is becoming popular as a sprinkler pipework material due to ist good smoke and flame properties.
Polypropylene is approved for use with foodstuffs, potable and ultra pure waters, hydronic heating and cooling, reclaimed and rainwater systems, compressed air lines, and geothermal applications, as well as within the pharmaceutical and chemical industries. Polypropylene is noted for its resistance to physical and chemical damage. Polypropylene is adversely affected by UV radiation and should have a protective coating if installed outside
When compared to other plastics, polyethylene shows excellent diffusion resistance, and because of this property, polyethylene has been used for gas conveyance for many years. PE is widely used for the conveyance of potable water and fire fighting mains. It is used as supply pipe in commercial and residential Low-flow irrigation systems and drip irrigation systems. Cross-linked polyethylene material (XLPE) is being used to replace copper and traditional plastic piping for transporting both hot and cold water. Oxidative-induction time is a routine test when assessing the quality of polyethylene pipes.
Polyvinylidenfluorine (PVDF) is a thermoplastic fluoropolymer with high virginity, as it is a homopolymer without any additives such as stabiliser and pigments. Therefore, PVDF is physiologically harmless and can be used in high-purity areas. Moreover, it characterises due to high chemical stability and chemical resistance. In comparison to other fluoroplastics PVDF is easy to process.
PVDF has a good resistance against UV- and gamma radiation and also a good resistance to ageing. As it is translucent, the media exposes UV radiation.
PVDF suits, acc. to "FDA "Title 21, Code of Regulations (USA) Chapter 1, part 177.2510" application of products in continuous contact with food stuff. It is approved for the application in converting plants and storages of the "US-Department of Agriculture (USDA)". PVDF comply also to the characteristic of "3-A Sanitary Standards for Multiple-Use Plastic Materials Used as Product Contact Surfaces for Dairy Equipment, Serial-No.2000".
Reproduction of microorganisms on PVDF
The surface of a product made of PVDF is unfavourable to the proliferation of microorganisms - as with glass. This conclusion is the result of an examination which has been executed within the framework of "Centre d'Enseignement et de Recherches des Industries Alimentaires et Chimiques" (CERIA at Brussels) by Solvay. Due to these properties PVDF is applied in the food (e.g. in dairies) as well as in the drug industry and in ultrapure ranges of the semi-conductor industry.
PVDF has an outstanding resistance to most inorganic and organic acids, oxidising media, aliphatic and armoatic hydrocarbons, alcohols and halogenated solvents. It resists halogens - especially bromine (but not fluorine) - and soft bases. It degrades of smoking sulfuric acids, some strong alkamine amines, concentrated and hot alkalines as well as alkaline metals. In high polar solvents, like acetone and ethyl acetate it can swell.
Ethylenechlortrifluorethylene (ECTFE) is a thermoplastic fluoropolymer with a unique combination of characteristics - a copolymere with a changing configuration of ethylene and chlorotrifluorethylene.
This material can be used for special applications where a high chemical resistance at high temperatures is required (e.g. free chlorine within the media and 98% sulphuric acid)
ECTFE has a good resistance against UV- and gamma radiation and also a good resistance to ageing. As it is translucent, the media exposes UV radiation.
ECTFE is suitable, acc. to "BgVV" for the safe application of products in continuous contact with food stuff. For avoiding every influence of smell and taste it is recommended to clean the food with water which has direct contact with ECTFE parts.
Reproduction of microorganisms on ECTFE
The surface of a product made of ECTFE is unfavourable to the proliferation of microorganisms- as with glass. This conclusion is the result of an examination which has been executed within the framework of a test of the HP-suitability of ECTFE. Due to these properties, ECTFE is applied in the food and drug industry and for ultra-pure water ranges.
ECTFE has a remarkable good chemical resistance against the most inorganic and organic chemicals as well as against solvents. Up to now there is no solvent known, which corrodes ECTFE below 120°C or shows crack formation. Only contact with chlorinated solvents show a small swelling. ECTFE should not be used for melted alkali metal or hot amines (e.g. aniline, dimethyle). An essential advantage compared to other thermoplastics is the chemical resistance of ECTFE against chlorine or chlorine compound also at higher temperatures.
PTFE / PFA lined steel
By applying a lining to the inside surfaces of carbon steel or stainless steel pipework, a very high performance corrosion resistant system can be manufactured
Lining materials can be PTFE, PFA, PVDF, PP, PE dependant upon the type of fluid to be conveyed and the operating conditions of the system.
A wide range of accessories can be supplied with the same high performance lining such as;
- Instrument tees
- Bulls eye sight glasses
- Ball valves
- Check valves
- Butterfly valves
- Expansion bellows
- Dip pipes
- Nozzle liners
- Adapter flanges
GRP and GRP Composite pipework
By using suitable resins GRP composite pipe systems can provide high chemical resistance, high strength, and light weight. As per the case with lining steel pipe, GRP pipe can also be fabricated with a lining material to provide extra chemical resistance.