Canal of nodular cast iron, abbreviation ball is in charge of, use be called " nodular cast iron " material is cast and become. This kind of material is through be being joined in the molten iron that goes out in smelt the ball changes an agent (it is magnesium or rare earth magnesium alloy normally) , make cast-iron medium black lead by piece shape turns into bulbiform, eliminated flake graphite to be opposite greatly thereby of iron matrix cut apart action.
One, what is canal of nodular cast iron?
Canal of nodular cast iron, abbreviationBall canal, use be called " nodular cast iron " material is cast and become. This kind of material is in passing the molten iron that goes out in elt, joinThe ball changes an agent(it is magnesium or rare earth magnesium alloy normally) , make cast-iron medium black lead by piece shape turns intoBulbiform, eliminated flake graphite to be opposite greatly thereby of iron matrix cut apart action.
The change of this kind of micromechani, make itsIntensity, plasticity and tenacityDou Yuangao at common casting pig, its function is close to Yu Gang, be called again accordingly "Cast steel is in charge of" .
2, basically characteristic
Canal of nodular cast iron is compositive the mechanical function of cast-iron corrosion resistance and steel, the characteristic is very outstanding:
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Intensity tall, tenacity is good: Tensile strength is 3 times what casting pig is in charge of, succumb 5 times intensity is casting pig canal. Have fixed outspread rate, can bear to certain foundation sedimentations and be out of shape, not easy fragile break.
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Corrosion resistance can be exceedingly good: Its corrosion resistance is more multiple than steel tube tower above to number decuple, suit to bury the ground to lay directly very much. Wall has cement mortar lining normally, protect conduit further and prevent water quality 2 times to pollute.
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Service life is long: Design service life can amount to 50-100 year, be " hundred years project " cornerstone.
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Installation is handy, sealing is good: UseFlexible interface(be like T model bear socket) , installation is fast, allow the deflexion of all angle, aseiatic performance is good, interface is sealed and reliable, not easy leak.
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Move maintain cost low: As a result of its Gao Ke relies on gender and long life, the integrated cost of complete lifecycle is very low.
3, basically workmanship
Canal of nodular cast iron basically is usedCentrifugal casting lawProduction:
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Fusion: The raw material such as cast iron, will useless steel fuses molten iron.
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The ball changes processing: The ball is joined to change agent and agent of be pregnant with in molten iron.
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Centrifugal casting: The metal pattern that rotates the high speed of molten iron infuse after the ball is changed (tubal model) in, shape below centrifugal force effect and cool quickly.
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Anneal: Cast shaping need tubal semifinished product to undertake high temperature anneal is handled, make among them cementite is decomposed, form the matrix that gives priority to with ferrite, obtain tall tenacity and plasticity thereby.
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Finishing and anticorrosive: Undertake gush zinc, beear brushs bitumen lacquer substandard anticorrosive processing, and the construction of cement mortar liner of wall.
4, basically use a field
Nodular cast iron is in charge of be the following domain almostMark matchs:
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Municipal feed pipe net: Arrive from water works of the userTrunk canalAndMatch conduit, it is the applied domain of its core.
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Municipal drainpipe net: Use at rainwater and sewage to discharge.
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Fire control manages a network: Regard reliable fire control water supply as conduit.
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Industrial domain: Use at carrying the abrasion stock such as ore pulp, coal fines.
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Agriculture irrigates.
5, interface form with norms
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Basically receive form of degree of lip-rounding:
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T bear insert interface: Commonly usedFlexible interface, through balata the circle comes true sealed, allow deflexion and displacement.
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K mechanical interface: Through pressing orchid with bolt close solid balata encircles implementation sealed, also be a kind flexible interface.
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Flange interface: Use at waiting for equipment join with valve, pump.
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Norms expresses:
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Normally with "Nominal diameter DN" express, unit millimeter.
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Common standards fromDN80ToDN2600Bigger even.
6, contrast with the deepness of relevant canal material
Basically receive form of degree of lip-rounding:
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T bear insert interface: Commonly usedFlexible interface, through balata the circle comes true sealed, allow deflexion and displacement.
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K mechanical interface: Through pressing orchid with bolt close solid balata encircles implementation sealed, also be a kind flexible interface.
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Flange interface: Use at waiting for equipment join with valve, pump.
Norms expresses:
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Normally with "Nominal diameter DN" express, unit millimeter.
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Common standards fromDN80ToDN2600Bigger even.
Understand the fixed position that nodular cast iron manages better to help you, next graphs from " relative cost " and " function / dependability asks " two dimension are spent, will its and solder plastic pipe of steel tube, PVC-U undertook comprehensive contrast:
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PVC-U plastic pipeFixed position is the solution of low cost, low demand, if village interior raises a canal.
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Solder steel tubeRelatively balanced on cost and function, but need depends on anticorrosive layer.
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Canal of nodular cast ironLocate forHigh-powered, Gao Ke relies on a genderplan of first selection of net of canal of municipal main force, its are complete lifecycle cost advantage is clear.
Besides chart medium core locates, they still have the following and crucial difference on technicality:
| Feature | Canal of nodular cast iron | Solder steel tube (+ outside anticorrosive) | PVC-U plastic pipe |
|---|---|---|---|
| Core advantage | High strenth, tall tenacity, immanent anti-corrosive, long life | Machine high strenth, Gao Cheng pressing, easily | The price low, wall is ooth, be able to bear or endure chemistry is corroded |
| Corrosion resistance | Admirable(noumenon anti-corrosive) | General(depend on anticorrosive layer quality completely) | Beautiful(do not rust) |
| Bear control capacity | Tall | Very tall | Medium low |
| Tenacity / fight concussion | Good (flexible interface, not easy fragile break) | Very (but anticorrosive layer is fragile bad) | Difference (easy brittleness craze) |
| Hydraulic function | Very (have cement liner) | Very (inside coating) | Admirable(wall ooth) |
| Installation | Convenient (bear insert join, need not solder) | Need solders or flange joins, speed slow | Special and convenient (gooey or bear insert) |
| Lifecycle cost | Low | Medium | Medium low |
| Main application | Municipal water supply / canal of catchment main force | High pressure is defeated by conduit of water, industry, wear span project | The water supply inside the building, village matchs conduit, catchment |
Summary and type selecting proposal
Canal of nodular cast ironBe examine through practice of permanent worker Cheng, use atMunicipal underground manages a networkReliable, durable, economytubal material.
How to choose?
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First selection nodular cast iron is in charge of: ToFeed pipe of urban main force net, Main line is defeated by water, To preventing the area with leak high demandAndGeological condition may produce sedimentationed area, the reliability that because its are outstanding,nodular cast iron runs, macrobian life and flexible the advantage of interface, it is unquestionable first selection.
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The choice solders steel tube: When actuating pressureExtremely tall, or needTop canal, pass throughWait for special construction, or tubal diameterVery big(exceed a ball to provide range) when, can use high quality solder steel tube and complementary with severe anticorrosive measure.
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Choose plastic pipe: ToThe architecture is internal, The village raises a canalOrDeciduous, Low-pressure forceproject, can choose the plastic pipe with lower cost.
Simple for, Canal of nodular cast iron is safety of safeguard city water supply " subterranean Great Wall " , it is the backbone strength that municipal foundation builds
