In architecture, structural engineering, or building, a purlin (or historically purline, purloyne, purling, perling) is a horizontal beam or bar used for structural support in buildings, most commonly in a roof. Purlins are supported either by rafters or the walls of the building. They are most frequently used in metal buildings, though they sometimes replace closely spaced rafters in wood-frame structures.
The purlins of a roof support the weight of the roof deck. The roof deck is the wood panel, plyboard, or metal sheeting that creates the roof’s surface. When made of wood, it is usually covered with weatherproofing and sometimes an insulation material.
Several kinds of purlins exist. There are several categories based on the material from which they are made and their shape. Different types of purlin have various utilities, including structural support of walls or floors. Purlin is important because, without it, there’s no frame for the sheeting on the roof to rest on, making purlins critical to the roof’s structure.
Wood Purlin is suitable for use with fiber cement sheeting. The wood purlin and sheeting combine well to ensure that the room below is breathable and can safely store whatever you need to be kept safe in the room, from livestock to grain or other organic materials.
However, being made from wood, purlins can rot. Besides, the main problem with wood is it being dry when it goes up. Therefore, it is best dried before installation. Moreover, the moisture can add significantly to the weight leading to sag.
Steel Purlin is a good alternative for wood purlin. It’s lightweight, dimensionally stable, accurate, and straight. Therefore, it expands and contracts reasonably in extreme temperature changes.
Cold-formed steel is the most common material for steel purlin because it is thin enough to put screws through. Cold-formed steel is made by rolling or pressing thin sheets of steel into the desired shape. It is less expensive for the manufacturer than hot-rolled steel and is also easier to work with. Though cold-formed steel is stronger than hot-formed steel, it is more likely to break under pressure than bend.
Purlins are manufactured from hot-dipped galvanized steel with a coating with other standard lightweight steel structural building products. This coating gives good protection in most exposed internal environments. Runoff from, or contact with, materials that are incompatible with zinc should be avoided.
To protect the purlin, they also apply a layer of paint outside them. Zinc and paint combined (synergistic effect) produce corrosion protection approximately 2X the sum of the corrosion protection that each alone would provide.
In the next section, we will present a detailed introduction and comparison of purlins. Understanding that purlins have a growing importance in construction works, Chinh Dai Steel has been perfecting our technology to supply c channel purlin and z purlin of the highest quality.
Purlin and Girt
Secondary framing is an essential component of many pre-engineered metal buildings. Also referred to as “secondary structurals,” this type of framing runs in-between primary framing elements, creating a structure-within-a-structure, much like cross-beams in a wooden building.
Secondary framing aims to distribute loads from the building’s surfaces to the primary framing and the foundation. This component can add longitudinal support that helps resist wind and earthquakes. And it can provide lateral bracing for compression flanges that are part of the primary framing, increasing overall frame capacity.
Secondary framing components are known as girts and purlins, and they work like this:
Girts provide additional support for walls: They work in conjunction with columns and wall panels to support vertical load, improving strength and stability. They also help attach and support wall cladding.
Purlins provide additional support for the roof: They create a horizontal “diaphragm” that supports the weight of your building’s roof deck – whatever material you use for the top itself. They also help make your entire roof structure more rigid. Because they add mid-span support, purlins allow longer spans, enabling you to create a wider building.
Eave struts are another kind of secondary framing. Also called eave girts or eave purlins, these are essentially a combination of the two. They’re used where sidewalls intersect with the roof, using a top flange that helps support the roof and a “web” that helps support the walls.
CEE and ZED Configurations.
Secondary framing comes in two configurations, CEE and ZED. They’re shaped on a bending press to create a web with two flanges. They come in various sizes; for instance, purlins can run over 30 feet in length.
Material for making Girts, purlins, and eave struts is almost always cold-formed steel. It’s more affordable and easier to work with. Still, it also presents some structural stability issues that you should consider for your metal building framing options and overall design. In particular, local or distortional buckling or lateral displacement can occur, in which portions of the compression flange, web, or connectors can buckle or shift from their initial position.
Problems can occur under extreme stress or even under relatively low stress if conditions are just right. However, you shouldn’t consider these engineering issues detractors if you’re considering a metal building. Additional stability or support can come from girts, purlins, and eave struts, and additional stiffeners.
Exactly how many and what size secondary framing elements your building may require will depend on your building’s dimensions, primary framing system, and how you plan to use the facility, as well as other factors. Your metal building company can explain the nuances in detail and guide you toward the right decision.
Roof purlin needs no introduction to anyone in the construction industry. In their design life, purlins are subject to dead load (e.g., self-weight of sheeting materials and accessories), live load (e.g., during maintenance services and repairs), and environmental loads (e.g., wind and snow load). Therefore, a purlin should be adequately strong to withstand the loads it will encounter during its design life and should not sag in an obvious manner, thereby giving the roof sheeting an undulating and/or unpleasant appearance. This post will be focusing on the design of steel purlin using cold-formed sections.
The span is the distance between centers of the cleat bolts at each end of the purlin. Each span type represents a complete purlin run system and recognizes that using separate component parts (e.g., internal span, end span) is not a valid procedure.
Single Purlin Span
A single purlin span is a span that is simply supported by bolting the purlin’s web to a cleat or other rigid structure. Under these conditions, bridging does not influence inward capacities, but outward capabilities vary depending on the number of rows of bridging.
Double Purlin Span
Double purlin spans are simply supported at each end and in the center. They may comprise only one purlin over the entire length or two purlins lapped together over the central support to provide continuity. Both inward and outward capacities are influenced by bridging double spans.
Continuous Purlin Span
Continuous purlin spans are simply at each end and a series of equally spaced intermediate supports. These tables are for spans: purlins are lapped over each other for support, where the lap length is 15% of the span—tables given for 5 or more spans. For outwards loads on equal continuous spans, the bridging shown is required in the end spans. You can use one less row of bridging for internal spans. If inwards capacity, the recommended minimum bridging and practical spacing requirements allow. For inwards loads, the required bridging in the table applies to all spans.
We generally recommend a lap length of 15% of the span. Where span lengths are unequal (e.g., reduced end spans), each purlin should have 7.5% of each adjacent span added rather than 7.5% of that purlin’s span.
Lap lengths of less than 10% (or 5% on any support side) may not provide complete structural continuity and may also suffer from local failures not considered by this method. You should further consider lap lengths beyond the scope of this manual.
Single cleats are used in most situations, including lapped Z purlins. Double cleats are generally only used where successive purlins (usually unlapped) are butted together. Double cleats could also be used in applications with a high reaction load to reduce bolt stresses. In this situation, Bolt Stresses would need additional care in hole detailing.
By default, purlin sections assume the slope of the roof they are supporting. The spacing of purlins usually calls for the careful arrangement because it should follow the nodal pattern of the supporting trusses. In this regard, purlins should be placed at the nodes of trusses and not on the members themselves so as not to induce secondary bending and shear forces on the members of the truss.
Furthermore, if the manual analysis is employed to analyze a truss loaded in such a manner, it cannot capture these secondary stresses since we usually assume pinned connections. Cold-formed Z (Zed) and C (Cee) sections are generally specified for purlins in steel structures (see their form in the image below).
Compared with thicker hot-rolled shapes, they usually offer the advantages of lightness, high strength, and stiffness, easy fabrication and installations, easy packaging and transportation, etc. The connection of purlins can be sleeved or butted depending on the construction method adopted.
In terms of the arrangement, we can have single spans with staggered sleeved/butt arrangement, single/double-span with staggered sleeve arrangement, double-span butt joint system, and single-span butt joint system. The adopted arrangement will depend on the supply length of the sections as readily available in the market, the need to avoid wasteful offcuts, the loading, and span of the roof, the arrangement of the rafters, etc. Therefore, the roof designer must plan from start to finish.
However, single and double span butt joint systems are the most popular in Nigeria due to their simplicity and the culture of shorter roof spans. Though, they are less structurally efficient than sleeved connections.
Bridging provides resistance to purlin rotation during the installation of roof and wall sheeting. For this reason, a maximum bridging (or bridging to cleat) spacing of 20 x purlin depth, but no greater than 4000, is recommended. Failure to do so can lead to misaligned fastenings, causing additional stress on the fasteners and roof sheeting. Excessive purlin rotation can be a safety hazard during construction.
The general rule is that you should use at least one row of bridging in each purlin span. Span/bridging configurations that exceed these recommendations are shown on the left or above the red line. However, in instances where sheeting is successfully installed outside of this recommendation, the published values are valid for structural purposes.
Purlins are installed horizontally under metal roofs: on top of the roof rafters with a felt underlayment or vapor barrier installed above.
Purlins are 2 by 4 feet and are installed much like metal roofing. They give added support to the roof and provide a nailing surface for the end panels and drip edges.
As shown below, purlin laps must be bolted in the top web hole and the lower flange holes at both ends of the lap. Bolting only in the web of lapped purlins does not provide full structural continuity. Excessive loads can put pressure on roofing screws that penetrate both purlins within a lapped region.
Purlin Flying Bracing
If the lower web hole in a lap is used for attaching fly bracing, ensure that you use an additional bolt.
Design Station Bridging can be installed either up or down the roof slope but cannot be mixed within a bridging run. However, as the starting and finishing components will be different, the direction of fixing must be established at the design/procurement phase. Girt bridging must not exceed its compressive capacity if you’re to install more than one row; always complete the bridging for each girt before commencing on the next (i.e. do not complete one row of bridging before starting the next).
We do not recommend the welding or hot cutting of purlins, girts, or bridging. The heat produced in welding will affect the material properties of the high yield strength cold-formed steel used in purlins. In many instances, considerable stress concentrations are likely to arise, even with good quality welding. In addition, welding will locally remove the protective coating, leading to a potential reduction in durability.
Purlin Handling and Storage
Roof Purlins must be kept dry during storage as water present between closed stacked sections will cause premature corrosion. If they become wet, they should be separated and stacked openly to allow ventilation to dry the surface.
The installation of Purlins can be hazardous and will require an adequate safety plan to be in place before handling or installing these products. All rigging, scaffolding, and safety equipment must comply with the relevant codes, Australian standards, and statutory requirements. We highly recommend that you follow good trade practices outlined in Australian Standards AS3828-1998 (Guidelines for the erection of building steelwork) and HB39 (Installation code for metal roof and wall cladding).
Typically, purlins are not designed to be walked on unless fully covered by correctly installed roofing materials or the correct grade of safety mesh. The manufacturing or delivery process may result in oil or grease adhering to these purlins, increasing the potential hazard. You mút carry out the handling of this product using a correctly supervised crane or appropriate lifting device.
Safety harnesses must always be used during the installation of purlins when working off the ground. Under no circumstances must any bodyweight be placed on bridging or on purlins or girts that have not been fully bolted into position with the correct bridging installed. Bolts must be the right size and grade, all progressively fully tightened during installation. Laps must be bolted in the outer web hole (closest to the sheeting) and the inner flange holes provided.
Last but not least, you have to choose the best supplier for you to order purlin. A reputable supplier with a solid customer base can ensure the purlin’s quality to a certain extent. Other than reputation, some elements make the best purlin supplier.
The production capacity of the manufacturer decides how long it takes you to receive the purlin. The higher the production capacity is, the shorter time you have to wait. It depends on the factory size and technology they applied. In general, big manufacturers have a higher production capacity.
When it comes to steel purlin, it’s essential to find a manufacturer with a production capacity of around 500MTS per day.
We recommend that production should be closed from raw material to final product. If so, the manufacturer can completely manage the quality of the purlin. If they are not steelmakers and need other steel suppliers, they cannot determine the exact material and production processes. What will happen if your purlin is rusty after 3 months of usage and when you contact your supplier, they blame it for the steelmaker. Moreover, it results in higher prices because the products’ prices include more transportation costs and benefits.
Each production stage should use different and modern production techniques. Modern machinery and advanced technology applied will save energy and reduce production costs. There are global standards for the quality management system and product quality such as ISO, Standards Australia, ASTM, JIS G, … Make sure you ask the supplier about their quality certification before ordering anything.
Professional consultancy is essential when you merely know about purlin and steel. They will help you decide the purlin sizes and span according to your place’s weather condition. They had better provide free consultancy, and it is convenient with 24/7 service.
If you are looking for a foreign supplier, they are needed to be familiar with exporting activities. You had better work with a knowledgeable and dynamic staff, pushing the process to go much faster.
After buying purlin, you still need assistance in setting and maintenance. You will be in trouble if your supplier disappears right after-sales because there will be no one to guarantee the quality of the products and take responsibility when they are faulty.
Chinh Dai Steel’s Purlin
Chinh Dai Steel is a professional supplier which specializes in producing purlin. Our products are popular in many international markets such as Australia, India, Myanmar, Indonesia, Laos. We have collaborated with many reputable partners: Samsung, Toyota, Thyssenkrupp, Mitsubishi, etc.
Quality management system: ISO 9001:2008 International Standard.
Product quality: JIS G standard, ASTM International Standard, AS/NZS International Standard.
Technology: seven technology steps, modern machinery, and advanced technology are applied to save energy and reduce production costs.
Production process: closed from raw material to final product. Each production stage uses a separate and modern production line.
Production capacity: 500MTS per day.
Product lifetime: more than 20 years.
Surface Treatment: chromate layer. The products are guaranteed to have a beautiful shine and gorgeous patterns. The zinc and chromate layer is thick and resistant to corrosion. It also helps to protect the inner layer for a more extended period.
Payment: Letter of Credit, T/T.
Packing: Steel pallet for Purlin
Delivery time: 30 – 60 days after receiving the deposit (depends on distance).
Communication: 24/7 hotline, 24/7 email, fax, website. We will reply to your inquiry within 24 hours.
Consultancy: free 24/7 consultancy. We will protect your private information.
Read more about Chinh Dai’s Exporting Channel.
Katika usanifu, uhandisi wa muundo, au ujenzi, purlin (au kihistoria purline, purloin, purling, perling) ni beam usawa au bar kutumika kwa ajili ya msaada wa muundo katika majengo, kawaida katika paa. Vipande hivyo hutegemezwa na mbao au kuta za jengo hilo. Wao hutumiwa mara nyingi katika majengo ya chuma, ingawa nyakati nyingine wao kuchukua nafasi ya rafters karibu spaced katika miundo ya mbao-frame. Vipande vya paa hutegemeza uzito wa sakafu ya paa. paa deck ni mbao jopo, plyboard, au chuma karatasi kwamba inajenga paa ya uso. Inapofanywa kwa mbao, kwa kawaida hufunikwa kwa kifuniko cha kuzuia hali ya hewa na nyakati nyingine kwa kifuniko cha kutenganisha. Kuna aina kadhaa za purlins. Kuna makundi kadhaa kulingana na vifaa vinavyofanyizwa na umbo lao. Aina tofauti za purlin zina matumizi mbalimbali, kutia ndani utegemezo wa muundo wa kuta au sakafu. Purlin ni muhimu kwa sababu, bila yake, hakuna sura kwa ajili ya karatasi juu ya paa kupumzika juu, kufanya purlins muhimu kwa muundo wa paa. Wood Purlin ni yanafaa kwa ajili ya matumizi na nyuzi saruji karatasi. Plin ya mbao na karatasi huunganisha vizuri ili kuhakikisha kwamba chumba cha chini kinaweza kupumua na kinaweza kuhifadhi kwa usalama chochote unachohitaji kuhifadhiwa ndani ya chumba, kutoka kwa mifugo hadi nafaka au vifaa vingine vya kikaboni. Hata hivyo, kwa kuwa zinatengenezwa kwa mbao, vifungo vya mbao vinaweza kuoza. Kwa kuongezea, tatizo kuu la mbao ni kwamba huwa kavu inapopaa juu. Kwa hiyo, ni afadhali kuifuta kabla ya kuiweka. Isitoshe, unyevu waweza kuongeza uzito kwa njia kubwa na kusababisha kuanguka. Purlin ya chuma ni mbadala mzuri kwa purlin ya mbao. Ni nyepesi, imara kwa vipimo, sahihi, na moja kwa moja. Kwa hiyo, hupanuka na kupungua kwa kiasi fulani wakati wa mabadiliko makubwa ya halijoto. Chuma kilichofanyizwa kwa baridi ni nyenzo ya kawaida zaidi kwa purlin ya chuma kwa sababu ni nyembamba vya kutosha kuweka screws kupitia. Chuma kilichofanyizwa kwa baridi hutengenezwa kwa kuunganisha au kushinikiza vipande vyepesi vya chuma katika umbo linalotakiwa. Ni nafuu kwa mtengenezaji kuliko chuma cha kuyeyusha moto na pia ni rahisi kufanya kazi nayo. Ingawa chuma kilichotengenezwa kwa baridi ni chenye nguvu zaidi kuliko chuma kilichotengenezwa kwa moto, ni rahisi kuvunjika chini ya shinikizo kuliko kuinama. Purlins ni viwandani kutoka moto-dipped galvanized chuma na mipako na bidhaa nyingine ya kawaida nyepesi chuma muundo wa ujenzi. Kifuniko hiki hutoa ulinzi mzuri katika mazingira ya ndani yaliyo wazi zaidi. Mtiririko kutoka, au kuwasiliana na, vifaa ambavyo haviwezi kuendana na zinki inapaswa kuepukwa. Ili kuwalinda, wao pia hutumia rangi nje ya vifuniko hivyo. Zinc na rangi pamoja (athari synergistic) kuzalisha ulinzi dhidi ya kutu takriban 2X jumla ya ulinzi dhidi ya kutu kwamba kila moja peke yake kutoa. Katika sehemu inayofuata, tutawasilisha utangulizi wa kina na kulinganisha ya purlins. Kuelewa kwamba purlin ina umuhimu unaozidi katika kazi za ujenzi, Chinh Dai Steel imekuwa kukamilisha teknolojia yetu ya kusambaza c channel purlin na z purlin ya ubora wa juu. Purlin na Girt Secondary framing ni sehemu muhimu ya majengo mengi ya chuma ya kabla ya uhandisi. Pia inajulikana kama <unk>mfumo wa sekondari,<unk> aina hii ya kuunda inaendesha kati ya vipengele vya msingi vya kuunda, kuunda muundo-ndani-ya-muundo, kama vile beams-msalaba katika jengo la mbao. Secondary framing inalenga kusambaza mizigo kutoka uso wa jengo kwa framing ya msingi na msingi. Sehemu hii inaweza kuongeza msaada wa urefu ambao husaidia kukabiliana na upepo na matetemeko ya ardhi. Pia, inaweza kutoa brace upande kwa flanges compression ambayo ni sehemu ya msingi frame, kuongeza jumla frame uwezo. Sehemu za pili za muundo zinajulikana kama girts na purlins, na hufanya kazi kama hii: Girts hutoa msaada wa ziada kwa kuta: Wanafanya kazi pamoja na nguzo na paneli za ukuta kusaidia mzigo wa wima, kuboresha nguvu na utulivu. Pia husaidia kuunganisha na kutegemeza mipako ya kuta. Purlins kutoa msaada wa ziada kwa ajili ya paa: Wao kujenga usawa <unk>diaphragm<unk> kwamba inasaidia uzito wa jengo lako <unk> paa deck <unk> chochote nyenzo wewe kutumia kwa ajili ya juu yenyewe. Pia husaidia kufanya jengo lako lote la paa liwe gumu zaidi. Kwa sababu zinaongeza msaada wa katikati ya mduara, vifungo vya mduara huruhusu mduara mrefu zaidi, ukikuruhusu kujenga jengo pana zaidi. Vipande vya juu vya mbao ni aina nyingine ya muundo wa pili. Pia huitwa girts ya paa au purlins ya paa, hizi kimsingi ni mchanganyiko wa hizo mbili. Wao ni kutumika ambapo sidewalls kukutana na paa, kwa kutumia flange juu ambayo husaidia kusaidia paa na "mtandao" ambayo husaidia kusaidia kuta. Utaratibu wa ZD na CZ Secondary framing inakuja katika miundo miwili, CEE na ZED. Wao ni umbo juu ya bending vyombo vya habari kuunda mtandao na flanges mbili. Kuna aina mbalimbali za pikipiki, kwa mfano, pikipiki za aina ya purlin zinaweza kuwa na urefu wa meta kumi. Vifaa vya kutengeneza Girts, purlins, na struts eave ni karibu daima chuma baridi-kufanyizwa. Ni nafuu zaidi na rahisi kufanya kazi nayo. Hata hivyo, kuna baadhi ya matatizo ya ujenzi ambayo unapaswa kuzingatia kwa ajili ya chaguzi yako ya chuma jengo frame na kubuni jumla. Hasa, buckling ya ndani au ya kupotosha au kuhamishwa kwa upande kunaweza kutokea, ambapo sehemu za flange ya compression, mtandao, au viunganishi vinaweza buckle au kuhamishwa kutoka kwa nafasi yao ya awali. Matatizo yanaweza kutokea chini ya mkazo mkubwa au hata chini ya mkazo mdogo ikiwa hali ni sahihi. Hata hivyo, unapaswa si kuzingatia masuala haya ya uhandisi detractors kama wewe ni kuzingatia jengo chuma. Usaidizi wa ziada au utegemezo unaweza kuja kutoka girts, purlins, na struts eave, na stiffeners ziada. Jinsi ya kupanua na kupanua sehemu za msingi za ujenzi wa jengo lako inategemea vipimo vya jengo lako, mfumo wa msingi wa ujenzi, na jinsi unavyopanga kutumia jengo hilo. Kampuni yako ya ujenzi wa chuma inaweza kueleza mambo madogo-madogo kwa undani na kukuongoza kuelekea uamuzi sahihi. Roof purlin haihitaji kuanzishwa kwa mtu yeyote katika sekta ya ujenzi. Katika maisha yao ya kubuni, purlins ni chini ya mzigo wa wafu (kwa mfano, uzito wa vifaa vya sheeting na vifaa), mzigo wa kuishi (kwa mfano, wakati wa huduma za matengenezo na ukarabati), na mizigo ya mazingira (kwa mfano, mzigo wa upepo na theluji). Kwa hiyo, purlin lazima kuwa na nguvu ya kutosha ili kuvumilia mzigo itakayokutana wakati wa maisha yake ya kubuni na haipaswi kuanguka kwa njia ya wazi, na hivyo kutoa safu ya paa na kuonekana ya kuvutia. Chapisho hili itakuwa kuzingatia kubuni ya chuma purlin kutumia baridi-kufanyizwa sehemu. Kipindi ni umbali kati ya vituo vya cleat bolts katika kila mwisho wa purlin. Kila aina span inawakilisha kamili purlin kukimbia mfumo na inatambua kwamba kutumia sehemu tofauti sehemu (kwa mfano, span ndani, span mwisho) si utaratibu halali. Single Purlin span ni span ambayo ni tu mkono na bolting purlin's mtandao kwa cleat au muundo mwingine ngumu. Chini ya hali hizi, bridging haina ushawishi ndani ya uwezo, lakini uwezo wa nje hutofautiana kulingana na idadi ya safu ya bridging. Double Purlin span ni moja ya aina ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu ya safu. Wanaweza kujumuisha tu moja purlin juu ya urefu wote au purlins mbili lapped pamoja juu ya msaada wa kati ili kutoa mwendelezo. Wote ndani na nje ya uwezo ni kuathiriwa na kuunganisha spans mara mbili. Mfuatano Purlin span ni tu katika kila mwisho na mfululizo wa sawa spaced msaada kati. Meza hizi ni kwa spans: purlins ni lapped juu ya kila mmoja kwa msaada, ambapo urefu lap ni 15% ya span <unk> meza zinazotolewa kwa spans 5 au zaidi. Mbele mizigo juu ya sawa kuendelea spans, bridging kuonyeshwa inahitajika katika mwisho spans. Unaweza kutumia safu moja chini ya bridging kwa spans ndani. Kama ndani uwezo, mapendekezo ya chini bridging na mahitaji ya vitendo umbali kuruhusu. Kwa ajili ya mizigo ya ndani, required bridging katika meza inatumika kwa spans wote. Kwa kawaida, tunapendekeza urefu wa mzunguko wa 15% ya span. Wakati span urefu ni tofauti (kwa mfano, kupunguzwa mwisho span), kila purlin lazima kuwa na 7.5% ya kila span jirani aliongeza badala ya 7.5% ya span kwamba purlin. Kwa vipindi vya chini ya 10% (au 5% kwenye upande wowote wa msaada) inaweza kuwa haitoi mwendelezo kamili wa muundo na inaweza pia kuathiriwa na kushindwa kwa eneo ambalo halikuzingatiwa na njia hii. Unapaswa pia kuzingatia urefu wa lap zaidi ya wigo wa mwongozo huu. Cleats moja ni kutumika katika hali nyingi, ikiwa ni pamoja na lapped Z purlins. Cleats mara mbili kwa ujumla ni tu kutumika ambapo purlins mfululizo (kwa kawaida unlapped) ni butted pamoja. Cleats mara mbili pia inaweza kutumika katika maombi na mzigo wa juu athari ya kupunguza msukumo bolt. Katika hali hii, Bolt Stresses ingekuwa haja ya huduma ya ziada katika ufafanuzi shimo. Kwa default, sehemu purlin kudhani mteremko wa paa wao ni kusaidia. Upana wa purlins kawaida wito kwa mpangilio wa uangalifu kwa sababu inapaswa kufuata muundo nodal ya trusses kusaidia. Kwa upande mwingine, purlins lazima kuwekwa katika nodes ya trusses na si juu ya wanachama wenyewe ili si kusababisha bending sekondari na nguvu shear juu ya wanachama wa truss. Zaidi ya hayo, kama uchambuzi wa mwongozo ni kutumika kuchambua truss kubeba kwa njia hiyo, haiwezi kukamata hizi mkazo sekondari tangu sisi kawaida kudhani pinned uhusiano. Baridi-kufanyizwa Z (Zed) na C (Cee) sehemu ni kwa ujumla maalum kwa purlins katika miundo ya chuma (tazama fomu yao katika picha hapa chini). Ikilinganishwa na umbo la moto-rolled, kwa kawaida hutoa faida ya upole, nguvu ya juu, na ugumu, utengenezaji rahisi na mitambo, ufungaji rahisi na usafirishaji, nk. Kuunganisha ya purlins inaweza kuwa sleeved au butted kulingana na mbinu ya ujenzi iliyopitishwa. Kwa upande wa mpangilio, tunaweza kuwa na spans moja na mpangilio wa sleeve-butt, spans moja na mbili na mpangilio wa sleeve-butt, mfumo wa pamoja wa butt wa spans mbili, na mfumo wa pamoja wa butt wa spans moja. Mpangilio uliopitishwa utategemea urefu wa ugavi wa sehemu kama inapatikana kwa urahisi sokoni, haja ya kuepuka kukata taka, mzigo, na span ya paa, mpangilio wa rafters, nk. Kwa hiyo, mbuni wa paa lazima apange mradi huo kuanzia mwanzo hadi mwisho. Hata hivyo, moja na mbili span butt pamoja mifumo ni maarufu zaidi katika Nigeria kutokana na unyenyekevu wao na utamaduni wa shorter paa spans. Ingawa, wao ni chini ya muundo ufanisi kuliko muundo muundo muundo muundo. Bridging hutoa upinzani kwa mzunguko purlin wakati wa ufungaji wa paa na ukuta karatasi. Kwa sababu hii, kiwango cha juu cha daraja (au daraja kwa cleat) nafasi ya 20 x kina cha purlin, lakini si zaidi ya 4000, inashauriwa. Kushindwa kufanya hivyo kunaweza kusababisha vifungo visivyo sawa, na kusababisha mkazo wa ziada kwenye vifungo na karatasi za paa. Mzunguko wa kupita kiasi wa mstari wa kuunganisha unaweza kuwa hatari kwa usalama wakati wa ujenzi. Kanuni ya jumla ni kwamba unapaswa kutumia angalau safu moja ya daraja katika kila span purlin. Span-bridge configurations kwamba kuzidi mapendekezo haya ni kuonyeshwa upande wa kushoto au juu ya mstari nyekundu. Hata hivyo, katika kesi ambapo sheeting ni mafanikio imewekwa nje ya mapendekezo haya, maadili kuchapishwa ni halali kwa madhumuni ya muundo. Purlins ni imewekwa usawa chini ya paa chuma: juu ya paa rafters na felted underlayment au mvuke kizuizi imewekwa juu. Mimea ya mviringo ni ya urefu wa mita mbili kwa mita nne na imewekwa kama paa la chuma. Wao kutoa msaada wa ziada kwa paa na kutoa nailing uso kwa paneli mwisho na kingo matone. Kama inavyoonyeshwa hapa chini, purlin laps lazima bolted katika shimo juu ya mtandao na mashimo ya chini flange katika ncha zote mbili za lap. Bolting tu katika mtandao wa lapped purlins haina kutoa mwendelezo kamili ya muundo. Mizigo mikubwa inaweza kusababisha shinikizo kwenye vijiti vya paa ambavyo huingia katika vifungo vyote viwili ndani ya eneo lililofunikwa. Kuunganisha kwa ndege: Ikiwa shimo la chini la mtandao katika lap linatumiwa kwa kuunganisha fly bracing, hakikisha unatumia bolt ya ziada. Design Station Bridging inaweza kuwekwa ama juu au chini ya mteremko paa lakini haiwezi kuchanganywa ndani ya kukimbia daraja. Hata hivyo, kama kuanza na kumaliza vipengele itakuwa tofauti, mwelekeo wa fixing lazima kuanzishwa katika hatua ya kubuni-upatikanaji. Girt daraja lazima si kuzidi uwezo wake compressive kama wewe ni kufunga zaidi ya safu moja; daima kukamilisha daraja kwa kila girt kabla ya kuanza juu ya ijayo (yaani. Usifanye mstari mmoja wa kuunganisha kabla ya kuanza mstari mwingine. Hatupendekezi kushona au kukata kwa moto vifungo vya chuma, vifungo vya chuma, au madaraja. Joto zinazozalishwa katika kulehemu itaathiri mali ya vifaa vya high yield nguvu baridi-kufanyizwa chuma kutumika katika purlins. Katika visa vingi, mkusanyiko mkubwa wa mkazo ni uwezekano wa kutokea, hata na kulehemu ya ubora mzuri. Kwa kuongezea, kulehemu kutaondoa kifuniko cha kinga mahali hapo, ikisababisha kupunguzwa kwa uwezo wa kudumu. Purlin Handling na Uhifadhi Roof Purlins lazima kuhifadhiwa kavu wakati wa kuhifadhi kama maji sasa kati ya kufungwa stacked sehemu kusababisha kutu mapema. Ikiwa zinakuwa na unyevu, zinapaswa kutenganishwa na kuwekwa wazi ili kuruhusu uingizaji hewa kukausha uso. Ufungaji wa Purlin unaweza kuwa hatari na itahitaji mpango wa usalama wa kutosha kuwa mahali kabla ya kushughulikia au kufunga bidhaa hizi. Vifaa vyote vya kuegesha, kuegesha, na vifaa vya usalama lazima vifuate kanuni husika, viwango vya Australia, na mahitaji ya kisheria. "Kama ilivyoelezwa katika kanuni za biashara nzuri za Australia, kanuni za biashara nzuri za Australia zinapatikana katika kanuni za Australia za AS 3828 na HB39 za ""Ujenzi wa Jengo la Chuma na Jengo la Chuma na Jengo la Chuma na Jengo la Chuma.""" Kwa kawaida, purlins si iliyoundwa kutembea juu ya isipokuwa kabisa kufunikwa na vifaa vya paa imewekwa kwa usahihi au darasa sahihi la usalama wa mesh. Utaratibu wa utengenezaji au utoaji unaweza kusababisha mafuta au mafuta kushikamana na purlins hizi, kuongeza hatari ya uwezekano. Unapaswa kufanya utunzaji wa bidhaa hii kwa kutumia crane inayoongozwa vizuri au kifaa sahihi cha kuinua. Vifaa vya usalama lazima daima kutumika wakati wa ufungaji wa purlins wakati wa kufanya kazi kutoka ardhini. Chini ya hali yoyote, uzito wa mwili haupaswi kuwekwa kwenye daraja au kwenye purlins au girts ambazo hazijawekwa kikamilifu katika nafasi na daraja sahihi imewekwa. Bolts lazima kuwa ukubwa sahihi na daraja, wote hatua kwa hatua kikamilifu tightened wakati wa ufungaji. Laps lazima bolted katika shimo nje web (karibu na sheeting) na shimo ndani flange zinazotolewa. Mwisho lakini si chini, ni muhimu kuchagua mtoa huduma bora kwa ajili ya bidhaa yako. Mtoaji mashuhuri na msingi imara wa wateja inaweza kuhakikisha ubora purlin ya kwa kiasi fulani. Mbali na sifa, mambo fulani hufanya mtoaji bora wa purlin. Uwezo wa uzalishaji wa mtengenezaji huamua ni muda gani unachohitaji kupokea purlin. Kadiri uwezo wa uzalishaji ulivyo mkubwa, ndivyo wakati unaohitaji kusubiri unavyokuwa mfupi. Inategemea ukubwa wa kiwanda na teknolojia waliyotumia. Kwa ujumla, wazalishaji wakubwa wana uwezo mkubwa wa uzalishaji. Kwa ajili ya pikipiki ya chuma, ni muhimu kupata mtengenezaji na uwezo wa uzalishaji wa karibu 500MTS kwa siku. Tunapendekeza kwamba uzalishaji unapaswa kufungwa kutoka malighafi hadi bidhaa ya mwisho. Ikiwa ndivyo, mtengenezaji anaweza kudhibiti kabisa ubora wa purlin. Kama wao si watengenezaji wa chuma na wanahitaji wauzaji wengine wa chuma, hawawezi kuamua vifaa sahihi na michakato ya uzalishaji. Ikiwa mti wako wa chuma umechakaa baada ya miezi mitatu ya matumizi, na unapowasiliana na muuzaji wako, wanalaumu mtengenezaji wa chuma. Zaidi ya hayo, ni matokeo katika bei ya juu kwa sababu bidhaa <unk> bei ni pamoja na gharama zaidi za usafiri na faida. Kila hatua ya uzalishaji inapaswa kutumia mbinu tofauti na za kisasa za uzalishaji. Mashine za kisasa na teknolojia ya hali ya juu zinazotumiwa zitahifadhi nishati na kupunguza gharama za uzalishaji. Kuna viwango vya kimataifa kwa ajili ya mfumo wa usimamizi wa ubora na ubora wa bidhaa kama vile ISO, ASTM, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO, ISO. Ushauri wa kitaalamu ni muhimu wakati unajua tu kuhusu purlin na chuma. Wao kukusaidia kuamua ukubwa purlin na span kulingana na hali ya hewa ya mahali yako. Kwa hivyo, ni bora kutoa ushauri wa bure, na huduma ya 24 7 ni rahisi. Kama wewe ni kuangalia kwa muuzaji wa kigeni, wao ni zinahitajika kuwa na ufahamu wa shughuli za kuuza nje. Ni bora kufanya kazi na wafanyakazi wenye ujuzi na wenye nguvu, kushinikiza mchakato kwenda haraka zaidi. Baada ya kununua purlin, bado unahitaji msaada katika kuweka na matengenezo. Ukifanya hivyo, utapata shida ikiwa muuzaji wako atatoweka baada ya mauzo, kwa sababu hakutakuwa na mtu wa kuhakikisha ubora wa bidhaa na kuchukua jukumu wakati zinapokuwa na kasoro. Chinh Dai Steel's Purlin Chinh Dai Steel ni muuzaji wa kitaalamu ambaye ni mtaalamu katika kuzalisha purlin. Bidhaa zetu ni maarufu katika masoko mengi ya kimataifa kama vile Australia, India, Myanmar, Indonesia, Laos. Tumeshirikiana na washirika wengi mashuhuri: Samsung, Toyota, Thyssenkrupp, Mitsubishi, nk. Mfumo wa usimamizi wa ubora: ISO 9001: 2008 Kiwango cha bidhaa: JIS G, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM, ASTM Teknolojia: hatua saba za teknolojia, mashine za kisasa, na teknolojia ya hali ya juu zinatumiwa kuokoa nishati na kupunguza gharama za uzalishaji. Utaratibu wa uzalishaji: kufungwa kutoka malighafi kwa bidhaa ya mwisho. Kila hatua ya uzalishaji hutumia mstari tofauti na wa kisasa wa uzalishaji. Uwezo wa uzalishaji: 500MTS kwa siku Urefu wa maisha ya bidhaa: zaidi ya miaka 20 Matibabu ya uso: tabaka la chromate. Bidhaa hizo zinahakikishwa kuwa na kung'aa kwa uzuri na michoro maridadi. Safu ya zinki na chromate ni nene na sugu kwa kutu. Pia husaidia kulinda tabaka la ndani kwa muda mrefu zaidi. Malipo: Barua ya Mikopo, T/T. Pallet ya chuma kwa ajili ya Purlin: 30 ~ 60 siku baada ya kupokea amana Mawasiliano: 24 7 hotline, 24 7 barua pepe, faksi, tovuti. Tutajibu maswali yako ndani ya masaa 24. Ushauri wa bure wa 24 7 Tutalinda habari yako binafsi. Soma zaidi kuhusu Kituo cha Uuzaji wa Chinh Dai.