CCHpdf. Uploaded by Pedro Figueroa Martínez. Copyright: © All Rights Reserved. Download as PDF or read online from Scribd. Flag for inappropriate. CCH (Inspection Steel Castings for HEPP Machines) – Free download as PDF File .pdf) or read online for free. Inspection Steel Castings for HEPP. CCH 70–2, CCH 70–3. DIN part 1, part 2. EN , EN , EN EN , EN EN , EN , EN EN , (ISO.
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We need your help to maintenance this website. Please help us to share our service with your friends. JuneCCHThesecond edition took into account theaccumulatedexperiencesduring the first years of use. June CCH The third edition adapted: For this third edition, it gathers 3 Founders, 3 Designers, from Europe and North America and 1 Independent control organization as well as several technical cousultants.
Subject to technical or economic circumstances as well as contract conditions, the Manufacturer may be mistaken for either theDesigner or the Founder or yet a third party FIRM separate from either ofthe other two. It will be the responsibility ofthe issuer of Quality Sheets QS to clearly complete those sheets, so as to define without ambiguity the place of examination and consequently the state of advancement required for the various controls prescribed.
It is therefore applicable for all items having at least one element inCast steel and constituing one Part of a hydraulic machine. It is recommendedthat the Designer includes one copy of the CCH in the technicalfile handed to the Powerplant upon delivery of the machine. The first mentionedare only fictitious examples for illustration. The indications given are in no way intended to serve as a rule, neither for the mechanicaltesting conditions nor for thechoice of the non-destructive testing method to be applied.
The highly stressed areas are indicated by two concentric circles. The Squares hatched or cross-hatched in blue, show different cases ofinspection restriction which may occur: The Squares with cross-hatched shading indicate that the type of inspection in question is very difficult or virtually impossible on the areas concerned because of limited-accessibility,incompatibility of shape and method or other reasons; Squares with single hatched shading represent unusual inspections due to diverse circumstances.
Blank Squares show those cases where the inspections are feasible but considered not to be necessary for the Casting to be inspected. The seconds mentioned specifythe purchase conditions andacceptance standards; they have to be filled in by the Designer with a maximum of objectivenesswith regard to the contract with his Customer.
These forms will not only determine the Casting quality,but also influence the prices. Indeed, the quality level required involves adefinite manufacturing routine and Special precautions to be taken by the Founder, the Manufacturer or the Designer. In this case each party will have to be aware of several Quality Sheets produced.
The Quality sheets should be part of: They will be legally valid in case of divergence with other documents. No other inspections exceeding those definedmay be required without mutual agreement of the interested parties. If complementary inspections are decided by such an agreement they will only have an informative value or will be the subjeet of an amendement to the Order. If a given area should be inspected by Spot checking only, the conditions will be defined after agreement between the parties.
If a confirmative radiographicinspection is forseen, radiography will only be carried out in case the results obtained by ultrasonics do not conform with the specified criteria and thus do not permit an evaluation of the acceptability of the indication.
The decision to repair or to perform a radiographic inspection for confirmation is left to the Founder see technical specification UT Beyond this depthclass 3 in PT or class 2 in MT is applicable. For certain highly stressedareas the Designer may specify more severe criteria.
This report will be submitted to the Designer. Any existing certified qualifications corresponding to the criteria defined will not be renewed. This heat treatment may only be omitted with the agreement of the Designer See 1. These repairs are executed by the Founder and are recorded. They may be undertaken by theManufacturer or the Designer after the approval ofthe Founder in accordance with the agreed and qualified welding procedure.
If such measures have not been taken, the repartition of costs should be fixed by a mutual agreement betweenthe Founder, the Manufacturer and the Designer prior to the commencement of work. The repartition of repaircosts may, for instance, be fixed on the basis of one of the criteria mentioned hereafter: The costs will be spread in accordancewith 5.
The Designer may advise the Founder for information purposes. The Customer will assume the cost of repairs.
The Designer decides to either: Subject to the conditions of his contract, the Designer will fch the Customer of the decisions taken orwill by agreement with the latter, find an acceptable solution.
Acceptance of a non conformity by the Customer in no way discharges theFounder, the Manufacturer or the Designer from their respective responsibilities.
This guarantee englagesthe Designer, Manufacturerand Founder to carry out all necessary repairsas soon as possible, by appropriate professional techniques defined by the CCH and procedures, and to ensure that the state of the repairedCasting meets the original specifications or, if such specifications have not been establishedto meet the professional Standard.
The Designer will not be allowed to impose more severe conditions to the 7-03 and the Manufacturer than the ones he has accepted himself. Usually, contracts fkx hydraulic machines require a guarantee covering a certain period of exploitation, after 703- reception of the installation, i.
Cc the diuersityof cases and types of exploitation, the duration of the guarantee must be subject to commercial negotiations betweenthe Customer and the Designer for each Order.
On this occasion, any useful information shouldbe transmitted to the party concerned. The party concerned by a request for application of the guarantee will as soon as possible propose an adequate repair procedure, executethe repairs and, in case of need, cch the necessary pieces.
It goes without saying that the party ensuring the guarantee reservesthe right to view that the deviation occurred. No repair will be effected without the agreement of the party considered responsible and only repairs which meet the instructions of this party will be carried out.
Any infringement of this regulation will leadto an annulment of any responsibility forthe other party. This method is generally limited to the inspection of finished Castings.
It may howeverbe applied at earlier Stages, especially for theinspection of excavations. That means that rust, scale, welding flux, spatter, grease, oil, water, dust, paint.
Table 1 The surfaces shall be prepared according to acceptance criteria. In case 703- superficial mechanical treatment e.
Cch 70 3 – Talk Vietnam
Scratching, hammering, shot blasting which may dull the Casting surface and thus hinder the penetration the of dye, the dye penetrantinspection should be preceded by a grinding of the surfaces to be inspected.
If magnetic particle inspection with liquid ink is intended, it isrecommended to perform liquid penetrant inspection first. The excessofpenetrant will be washedofand the Part dried. The examination is made afterapplication of a coat of developer, suspended in a liquid.
The products used shall be of high sensitivity. The products generally available on the market and the Operation methods described hereafter can be used within a temperaturerangeofabout 10 to 40″ C of the surface to beinspected.
Beyondthese limits, the efficiency of the products and of the process must be proved at the temperature at which the inspection is intended to be carried out. Any other method may be applied after previous agreement. Thenany traces of dust or greasehave to be eliminated fromthe surface by means of a solvent orby means of steamed water under pressure.
Theproducts used must meet the requirements of National legislation with regard to the environment. Minimum penetration soaking time is 10 minutes, but longer penetration timesmay be necessary on polished surfaces, narrowdiscontinuities or at temperaturesbelow 15 “C. Generally, soaking times will be 10 to 20 minutes. It must be assured that the surface is kept wet during this period.
The water jet shall be at least 30 cm from the surface. Then the part will be immediately dried with a dry, clean and lint free rag.
The drying may be accelerated by using dry non oily compressed air at a pressure of less than2 bar. As developer, a suspension ofpowder in a solvent is used. It is recommendedto apply the developer by a pistol immediately after preparation mixing, shaking to inforce uniform suspension. Thick coats of developer are unacceptable. Drying is produced by natural evaporation.
After a developing time of 10 to 20 minutes, the indications will be compared with the acceptance criteria. Lighting should be higher than Lux. PT elliptic and their length is less than three times the indications are those, in which the maximum length represents mor than three times the average width extension. As a reference, the above example contains 6 indications, all taken into consideration. The total surface thus taken into accont is of 6.
See PT Paragraph 4. As a reference, the above example contains8 indications, 3 of which aren’t taken into account.
As a reference, the above example contains 28 indications, 7 of which aren’t taken into account. This examination isnot applicable to austenitic steels and must bethe subject of an agreement between the contractual parties in so far as the inspection procedures are concerned, when it is used on Duplex austenoferritic steels.
The magnetic particle inspection is 70-33 carried out on as Cast, rough machined or finished surfaces, while considering that thereexists the possibility of deterioration of the parts when certain magnetization processes are used superficial burning. Surface preparation intensity depends on the need to reveal finer discontinuities. Table I The surfaces are 70–3 prepared in relationto the acceptance criteria.
Extensive shot blasting can prevent the fch of defects and could even hide them; forthis reason we recomendto limit shot blasting to a minimum. This requirement is generally metwith a tangentialfield of N m 25 Oe for unalloyed steels, Average value of rectified current 1 alternation, effective value of alternating current ;for allyoyed steels, higher fileds values may be necessary.
The valuethus Chosen must be considered as a minimum on the totality of the area inspected. A magneticfield of excessive valuecan cause the appearances of aberrant indications because of Saturation. These processes are not equivalent to each other with regard to: T0 insure that all orientation discontinuities are detected, it is necessary to use at leasttwo directions of magnetization which should preferably be perpendicular to each other.
Regardless of the process or processesChosen by the User, their efficiency will have to be demonstrated. A particular proceduremay be 7-3 by the Manufacturer. The air gap between the poles andthe Part must be limited to a minimum to avoid magnetic leaks. This mode of magnetization revealsdiscontinuities of which the significant dimension is perpendicular to the axis connecting the poles of the apparatus.