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33mm id brass tube

author:MF manufacturerstime:2022-03-14 08:09:15

(33mm id brass tube)1 Level setting

GivenGC1Specialty of pipeline,Medium properties should be in design、Design conditions、Selection of materials, etc.GC1 Class type medium pipeline separately set rating。Avoid unnecessary waste of pipeline materials for high prices for unnecessary media lines

2 Pipe standard

(33mm id brass tube)existTSG D0001 Table1 Some pipe standards are specified inGC1 Requirement of stage media,Designed to perform various requirements in this table。

(33mm id brass tube)Stainless steel welded steel pipe standard,Needless not to chooseHG/T20537,First, because the standard year is more a long time,In metallurgy、welding、Today's new month,Some requirements in the standard have been behind the technical perspective;Another reason is,ComparedGB/T12771-2008 standard,This standard is small, It is also small for producing steel pipe.。So the design is more choiceGB/T12771。

surface1 RegulationGB/T8163、GB3087、GB/T9711.1 Can't be usedGC1 Class media line,But in their comments7 There is a supplementary statement:After tachops, ultrasonic detection and meets qualified requirements,Allow design pressure≤4.0Mpa This procedureA1.1(1)Provisions。

This note is different fromGB/T20 01.2 Demand,This is related to the year of the two standards。The reason why the norm is used to use these three standard pipes,Mainly because of these three standards in manufacturing、test、Test requirements are lower,UsefulGC1 Level pipeline,There is a certain risk。Design,Need to consider the economics and safety of pipes,Do optimal。

(33mm id brass tube)CurrentlyGB/T9711 Series standard has been upgradedGB/T9711-2017。New version,Steel pipe gradePSL1 The corresponding is the originalGB/T9711.1 Pipe,PSL2The corresponding is the originalGB/T9711.2 Pipe。exist《National Pressure Pipeline Design Approval Personnel Training Textbook》Third edition,rightGB/T9711 Usage limit and attachment1 MediumGB/T9711.1 The provisions are the same。When this standard is selected,Note that it is not allowed to use。

(33mm id brass tube)GB/T9948-2013、GB/T6479-2013 andGB/T5310-2017 UsefulGC1 Level seamless pipeline is optional。From the respective names of these three standards, they can see the side weight of their usage.。Also pay attention to some unique requirements in the standard,

for example:onlyGB6479 The low temperature impact test of high quality carbon steel is provided;InGB9948-2013 Requirements and steel pipes for intermediate corrosion testsH2S Environmental supplemental technical requirements。GB5310 It is a standard set for steel pipes for boilers,Therefore, more for steam and their condensate lines。

For design pressure is greater than or equal to10Mpa ofGC1 Class media line,existSH/T3059 Regulation:Seamless steel pipe for design pressure≥10Mpa Time,Manufacturing and inspection should comply withGB5310、GB9948 orGB6479 Provisions,Stainless steel pipe test should be no less thanGB/T14976 Provisions[4]。

This requirement is different fromGB50316Demand, The reason for these two specifications, Mainly becauseGB50316-2000(2008 Version)Post-release,The quality grade of the tubes in these three standards is the order of low to high.:GB9948<GB5310<GB6479 。

But currently these three standards,Whether it is manufactured from processing or inspection、The requirements in the test have been basically the same。From these three standards of their use,SH/T3059 Requirements more reasonable。Such as exceeding10Mpa Steam media,ChooseGB5310 CompareGB6479 More suitable。

For the rating of foreign pipe standards,TSG D0001[1]Regulation:Directly adopt international standards or foreign standards,It should first turn it into an enterprise standard or engineering regulations.。forGC1 Level pipes should also be reported to the State Administration of Quality Supervision, Inspection and Quarantine。

when necessary,Entrust relevant technical organization or technical institutions by the State Administration of Quality Supervision, Inspection and Quarantine。Currently in China's foreign standards,The best choice,The technology applied to the use of the native pipe is also mature.,Press and followASMEB31.3Implementation of the corresponding requirements for pipes。

3 Fitting fitting

(33mm id brass tube)(1)Standard fittings。The selection of pipeline standards can have project regulations or self-selected。For seamless fittings,Because it can be manufactured by steel pipes from different standards,Therefore, after the selection of the pipeline standard,Need to indicate the standard number of the raw materials,In order to make the pipe fit to the same requirements as the pipe。For forged pipe fittings,Some design will make the forgings.。This is necessary。

(2)Non-tube。The most common non-standard tube parts have a bend、Oblique elbow、Absence、Snantle three-way。The use range of the elbow is not limited in the relevant standard,Given that the quality of production and manufacturing is difficult to ensure,GC1 Better pipes best purchased finished products。

The processing and manufacturing requirements will be indicated in the purchase file.,To ensure that the elut can be safely used。Unless confined and work requirements,It is not recommended to do special pipe fittings in the material level。

4 valve

CurrentlyGB/T20801.3 MediumGC1 The requirements for the valve of the level pipeline are more detailed.,The requirements will be analyzed in the following requirements.:Special petrochemical valve should be selected;

(1)The valves under such standards have been practiced and inspected for many years.,Quality and acceptance requirements are also higher。GB/T20801.3 Most of the programs listed in most have been upgraded,In design,according toSH/T3059 The selection standard for the selection is more in line with this article.。

(2)Should prevent the leakage of the fluid medium at the stem filler;This requirement mainly considersGC1 Toxicity、Flammability、Both higher than other class fluid media。The leak of the valve will cause environmental pollution and safety hazards.。

The leakage effect of the protection valve rod is the bellows sealing valve,But because of its difficulty of processing、Technical requirements are high、The bellows still does not fully realize localization,Excessive cost,Thereby restricting its large number of promotion in the petrochemical industry。Media for extreme hazards and high hazards,From the perspective of personal safety,Can consider selecting this type of valve。

(33mm id brass tube)In the standard in the valve, the sealing test is the requirements for the leakage of the valve stem.;AnotherISO15848The leakage of the upper valve stem is calculated according to the diameter of the stem.,And graded the leak,In the actual design,Characteristics of combination,Choose a suitable valve structure and appropriate leak level,Fundamentally eliminate the leaks at the valve valve stem。

(3)The sealing structure of the valve cap or the valve cover should be one of the following forms.:

①Flange connection,Bolt number≥4,And the gasket is in line withGB/T20801.3middle5.1.9 Regulation;existGB50316、ASME B31.3 Also require:Leaves are less than4 Bolt or useU Bolt bolts are fixed to the valve cover of the bolt connection of the valve body,InD Class fluid condition。

The valve standard of the table is specified in the bolt of the flange connection valve cover.4 indivual。This requirement and the following requirements are to prevent leakage of the diameter medium。

The type and material of the gasket is also one of the valve specifications.,existAPI 600 The form of sealing surfaces can be selected in the valve body and the valve cover connection,After determining the form of the sealing surface,may be combined in accordance with this clauseHG/T20592~20635 requirements in,According to the actual situation of the medium,Choose the right gasket type。

②self-tightening structure;This structure can effectively prevent medium leakage at the valve cover。This structure is inAPI 6D、NB/T47044 mentioned,But no more detailed regulations。From the principle of sealing,The seal at the bonnet is divided into forced seal and self-tightening seal,The typical structure of the forced seal is the gasket seal,Usually used for low pressure、Medium pressure and small to medium bore valves;

compared to forced sealing,Self-tightening sealing structure when the valve cover is moved up by the medium pressure,The sealing ratio between the bonnet and the wedge gasket and between the valve body and the wedge gasket,gradually increases with increasing pressure。The medium pressure in self-sealing always tends to increase the specific pressure of the preload seal,Increase sealing performance。

The higher the medium pressure,The greater the specific pressure of the working seal,better sealing performance。According to this characteristic,Self-tightening sealing as a high pressure sealing technology,Commonly used with high temperature or high pressure large diameter valve。

(33mm id brass tube)③Full penetration welded construction;This structure is the most effective way to prevent leakage at the valve cover,Not affected by valve size、Use pressure and temperature limits。But for in-line repairable valves,During maintenance,Need to remove the weld,Therefore, it is often used on valves that can be used for a long time without maintenance.;Or this kind of valve is more important to obtain the reliability of the sealing of the bonnet connection than to overcome the difficulties in overhauling the inside of the valve。

④Cylindrical thread connection,The strength check is qualified and the metal sealing welding is adopted;In view of the limitations of the use of cylindrical threads,and requires metal seal welding,Disadvantage as abovec)listed,The valve cover connection of this structure is rarely selected in engineering design.。

⑤Threaded bonnet seals shall not be used;The structure is not onlyGC1 media-like pipeline,Valves on other types of process medium pipelines are also rarely used,Generally used for low vibration during use,On small valves that do not require frequent disassembly。

⑥Valves for flammable fluids with non-metallic sealing materials,Should meet fire test requirements,And should be based on the pressure that non-metallic materials can withstand-The temperature rating determines the pressure of the valve-temperature rating。

This requirement is mainly to ensure that in the event of a fire hazard,Valve still has shut-off capability,Avoid secondary disasters。Non-metallic materials due to their own properties,temperature-limited pressure capacity,when selected,Strictly follow the requirements of the standard,Check temperature-pressure value。

Be careful when choosing materials not listed in the standard,different manufacturers,given temperature-Pressure values may vary。not the only option,It is not recommended to use non-metals beyond the standard as the sealing surface material。

(33mm id brass tube)5 flange

Flange selection focuses on flange type and sealing surface,GB/T20801.3stipulated in:Expansion flanges and threaded flanges shall not be used forGC1 stage pipeline;Severe cycle conditions orGC1 Grade pipeline,and the nominal diameter of the socket welded joint is greater thanDN50 Socket welded connections shall not be used。

existSH/T3059 stipulated in:poisonous、Combustible medium pipeline,Flat welding flanges shall not be used。GB50316againstA1 Fluid-like regulations:

(1)Flat welding should not be used(tablet)flange;

(2)Except for welding lip gaskets,The selection of flange nominal pressure should be reserved≥25%margin,and should not be lower than the nominal pressure2.0Mpa;

(3)When using soft gasket,Convex or tongue-and-groove flanges should be used[3]。

All of the above are required to strictly follow the specifications

6 Gasket、bolt、nut

Gasket selection should be based on fluid properties、Operating temperature、Comprehensive consideration of factors such as pressure and flange sealing surface。

HG/T20592~20635 There are detailed instructions on the operating temperature of various gaskets and the matching use with various types of flanges.,The design can be combined with this standard andGB/T20801.3、SH/T3059 Select the appropriate gasket material and type according to the requirements in。

in addition,Special attention should be paid to the usage restrictions of some gaskets,for example:combustible material(like rubber)gasket made,It shall not be used for pipelines transporting strong oxidizing media, etc.。

It is worth noting thatHG/T20592~20635 of fasteners,There are hexagon head bolts in the European standard series、Equal Length Studs and Full Threaded Studs;American Standard series only hex head bolts and full threaded studs,Different selection criteria,The corresponding fastener forms are also different。

existHG/T20634 Hexagon head bolts andⅠThe use of type hexagon nuts should meet the following requirements:Nominal pressure rating≤Class150;non-toxic、Non-flammable media and non-violent circulation occasions;With non-metallic flat gasket。Except in this case,Special grade full threaded studs and special nuts should be used。

according toGC1 Properties of Grade Pipeline Media,known to be used forGC1 Grade pipe grade fasteners can only use special grade full threaded studs and special nuts。SH/T3404 andHG/T20634 The type of fasteners in the,The requirements for the use of fasteners in this standard are the same asHG/T20634。

7 branch connection

The branch table is an important part of the pipeline hierarchy,existGB/T20801.3 stipulated in:GC1 The branch pipe connecting pipe fittings for grade pipeline shall adopt integrally reinforced branch pipe connecting pipe fittings or tee[6];GB50316 defined inA1 fluid-like andA2 in classⅡClass fluids also require that the branch pipe connection should be preferably a standard tee,Followed by branch table or embedded branch[3]。

According to these requirements of the specification,GC1 branch connections at the pipe level,If there are standard connecting pipe fittings, standard branch pipe fittings should be used。Can not choose branch pipe connection pipe fittings,according toGB/T20801.3、SH/T3059Provisions on the calculation part of the reinforcement in the middle:forGC1 Grade pressure pipelines should not be reinforced with reinforcing plates。

For this requirement, it is mainly considered that the reinforcement metal distribution of the reinforcement plate structure is too scattered,Reinforcement efficiency is not high;The reinforcement ring and the shell metal cannot be fully fitted,Poor heat transfer,When used at medium temperature and above,There is a large difference in thermal expansion between the two,Therefore, a large thermal stress is generated in the reinforced local area.;

In addition, the reinforcement ring and the shell are connected by lap welding.,Difficult to integrate with the housing,poor fatigue resistance;Reinforced welded structure compared to other forms of reinforcement,Welding stress is also high[11]。In view of these defects of reinforcement circle reinforcement,The branch design can be carried out in the way of overall reinforcement。