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1.Cutting
For the plastic-lined compound steel pipe, when required to be cut. It's necessary to use a toothed saw (hand saw or automatic saw machine),for the compound steel pipe lined with stainless steel. Both toothed and toothless saws are applicable. When pipe is cut, the end face of the pipe should be kept perpendicular to the axis of the pipe the pipe ends must be repaired and maintained with scraper after cutting. |
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2.Threading
Hand or electric threading machines are suitable for threading. Attention should be paid to cooling of the body of pipe when screwing plastic-lined compound steel pipe. After screwing pretection measures to thread must be taken.
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3.Installation of pipe
Cover the thread of pipe end with a layer of sealing material, connect pipe to pipe fittings, and appropriately tighten them with pipe pliers.
4.Repair of surface
After completion of installation, coat the exposed threads and damaged places with rust inhibitor so as to pretect pipes. |
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Comparison between hot dip galvanized steel pipe and traditional electroplated steel pipe
| Pipe material |
Structure and properties of plating |
Remark |
| Hot dip galvanized steel pipe |
There is a complicate physical and chemical reaction between the base of steel pipe and melted galvanization liquid, a zinc-iron alloy layer which is anticorrosive and possesses tight structure is formed, the alloy layer integrates with pure zinc and the base of steel pipe, so it is of good anticorrosion. |
Suitable for water supply in construction engineering |
| Traditional electroplated steel pipe |
Zinc layer is plating, and independent of the base of steel pipe, the zinc layer which is thinner, and just adheres to the base of steel pipe, is easy to shed off. It is of bad anticorrosion. |
The eletroplated pipe is prohibited to be used in water supply innew-built residential buildings |
Comparison of properties between walsall pipe and other pipe
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Material |
Working pressure |
Insolation andradiation |
Working temperature |
Mechanical strength |
Price |
| Walsall hot dip galvanized steel pipe |
CS/Zinc |
=1.6Mpa |
Prolong life |
suitable for hotand cold water |
Rigid pipe |
Medium |
| Walsall hot dip galvanized steel pipe lined with stainless steel |
CS/SS/Zinc |
=1.6Mpa |
Prolong life |
suitable for hotand cold water |
Rigid pipe |
High |
| Aluminium-plastic pipe |
Plastic/Aluminium |
=1Mpa |
Quicken ageing of plastic |
Fall into heat and cold water pipe |
Pliable pipe |
Low |
| Plastic pipe |
Plastic |
=1Mpa |
Quicken ageing of plastic |
Mainly suitable for cold water |
Pliable pipe |
Low |
Attention during installation
It is well known that zinc has positive pole protective effect on the base of steel pipe. The pure zinc layer on the surface of hot dip galvanized steel pipe can at atmosphere generate a tight and passivated [ Zn2(OH)2CO3] film which can further prevent zinc from corrosion .The hot dip galvanized steel pipe which thickness of the galvanization layer is above 50µm, can be safely used for 30 years in reasonable environment. Please pay attention to 'reasonable environment', as zinc is a relatively active amphoteric element which can react on acid and alkali, and also can replace the heavy metal ions of salt, the galvanization layer is easy to suffer from destruction and to be holed by corrosion in moisture environment with medium of acid, alkali salt.
If hot dip galvanized steel pipe is intended to be buried in wall or underground (toilet of living room) it is suggested that the buried surface of the steel pipe be processed (such as coated with bitumen, epoxy paint or covered with channel) so as to prevent galvanization layer from direct contact with medium. It is better to be refilled with dry neutral earth. At present we promote a new type of acid and alkali resistance pipe-epoxy anticorrosive paint coated pipe (compound pipe).
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