Month: March 2022

Optimizing Resource Deployment in Multi-Host Systems Using PCIe Switch Fabric Fabric

More and more data centers and other high-performance computing environments are using GPUs because of their ability to rapidly process the massive amounts of data generated in deep learning and machine learning applications. However, like many new data center innovations that improve application performance, this innovation exposes new system bottlenecks. In these applications, emerging architectures for improving system performance involve sharing system resources among multiple hosts through a PCIe® fabric.

The PCIe standard (especially its traditional tree-based hierarchy) limits how (and how much) resource sharing can be achieved. However, it is possible to implement a low-latency, high-speed fabric approach that allows a large number of GPUs and NVMe SSDs to be shared among multiple hosts, while still supporting standard system drivers.

The PCIe fabric approach uses dynamic partitioning and multi-host single-root I/O virtualization (SR-IOV) sharing. Point-to-point transfers can be routed directly between PCIe fabrics. This provides optimal routing for point-to-point transfers, reduces root port congestion, and balances the load on CPU resources more efficiently.

Traditionally, GPU transfers had to access the CPU’s system memory, which led to memory sharing contention between endpoints. When the GPU uses its shared memory-mapped resources instead of CPU memory, it can fetch data locally without passing it through the CPU first. This eliminates jumpers and links and the resulting latency, allowing the GPU to process data more efficiently.

Inherent limitations of PCIe

The PCIe master level is a tree structure in which each domain has a root complex, from which point can be extended to “leafs” that travel through switching fabrics and bridges to endpoints. The strict hierarchy and directionality of links impose costly design requirements on multi-host, multi-switch systems.

Optimizing Resource Deployment in Multi-Host Systems Using PCIe Switch Fabric Fabric

Figure 1 – Multi-host topology

Take the system shown in Figure 1 as an example. To comply with the PCIe hierarchy, host 1 must have a dedicated downstream port in switch fabric 1 that connects to a dedicated upstream port in switch fabric 2. It also requires a dedicated downstream port in switch fabric 2 that connects to a dedicated upstream port in switch fabric 3, and so on. Host 2 and Host 3 have similar requirements, as shown in Figure 2.

Optimizing Resource Deployment in Multi-Host Systems Using PCIe Switch Fabric Fabric

Figure 2 – Tier requirements for each host

Even the most basic system based on the PCIe tree structure requires three links between each switch fabric dedicated to each host’s PCIe topology. Also, since these links cannot be shared between hosts, the system can quickly become extremely inefficient.

Additionally, a typical PCIe compliant tier has only one root port, and while multiple roots are supported in the “Multi-Root I/O Virtualization and Sharing” specification, it complicates the design and is not currently supported by mainstream CPUs. The result is that unused PCIe devices (ie endpoints) are stuck in the host to which they are assigned. It’s not hard to imagine how inefficient this can become in larger systems with multiple GPUs, storage devices and their controllers, and switching fabrics.

For example, if the first host (host 1) has consumed all computing resources, and hosts 2 and 3 are underutilizing resources, then obviously host 1 is expected to have access to those resources. But Host 1 cannot do this because these resources are outside of its hierarchical domain and thus lingering occurs. Non-Transparent Bridging (NTB) is a potential solution to this problem, but it also complicates the system since each type of shared PCIe device requires non-standard drivers and software. A better approach is to use the PCIe fabric, which allows the standard PCIe topology to accommodate multiple hosts with access to each endpoint.

Method of implementation

The system is implemented using a PCIe fabric switch fabric (in this case, a member of the Microchip Switchtec® PAX family) in two separate but transparently interoperable domains: the fabric domain that contains all endpoints and fabric links and a dedicated domain for each host. host domain (Figure 3). The host is kept in a separate virtual domain via the PAX switch fabric firmware running on the embedded CPU, so the switch fabric will always appear as a standard single-layer PCIe device with directly connected endpoints, regardless of where those endpoints appear in the fabric It doesn’t matter.

Optimizing Resource Deployment in Multi-Host Systems Using PCIe Switch Fabric Fabric

Figure 3 – Independent domains for each structure

Transactions from the host domain are translated into IDs and addresses in the fabric domain, and vice versa for non-hierarchical routing of communications in the fabric domain. In this way, all hosts in the system can share the fabric links connecting the switching network and the endpoints. The switch fabric firmware intercepts all configuration plane communications from the host (including the PCIe enumeration process) and virtualizes a simple PCIe-compliant switch fabric with a configurable number of downstream ports.

While all control plane traffic is routed to the switch fabric firmware for processing, data plane traffic is routed directly to endpoints. Unused GPUs in other host domains are no longer stuck, as they can be dynamically allocated based on the needs of each host. Peer-to-peer communication is supported within the fabric, which makes it suitable for machine learning applications. Standard drivers can be used when providing functionality to each host in a PCIe-compliant manner.

How to operate

To understand how this method works, let’s take the system in Figure 4 as an example, which consists of two hosts (Windows® for Host 1 and Linux® for Host 2), four PAX PCIe fabric switches, four It consists of an Nvidia M40 GPGPU and a Samsung NVMe SSD that supports SR-IOV. In this experiment, the host runs communications representative of real machine learning workloads, including Nvidia’s CUDA peer-to-peer communications benchmark utility and a TensorFlow model that trains cifar10 image classification. The embedded switch fabric firmware handles low-level configuration and management of the switch fabric, and the system is managed by Microchip’s ChipLink debug and diagnostic utility.

Optimizing Resource Deployment in Multi-Host Systems Using PCIe Switch Fabric Fabric

Figure 4: Dual Host PCIe Fabric Engine

Four GPUs are initially assigned to host 1, and the PAX fabric manager displays all devices found in the fabric where the GPUs are bound to the Windows host. However, the structure on the host is no longer complicated, and all GPUs appear to be directly connected to a virtual switch fabric. Subsequently, Fabric Manager will bind all devices and Windows Device Manager will show GPUs. The host sees the switch as a simple physical PCIe switch with a configurable number of downstream ports.

Once CUDA discovered the four GPUs, the peer-to-peer bandwidth test showed a one-way transfer rate of 12.8 GBps and a two-way transfer rate of 24.9 GBps. These transfers go directly across the PCIe fabric without going through the host. If you run the TensorFlow model used to train the Cifar10 image classification algorithm and distribute the workload across all four GPUs, you can release two GPUs back into the fabric pool, unbinding them from the host. This frees up the remaining two GPUs to perform other workloads. Like the Windows host, the Linux host sees the switch as a simple PCIe switch without custom drivers, and CUDA can also discover the GPU and run P2P transfers on the Linux host. The performance is similar to that achieved using a Windows host, as shown in Table 1.

Table 1: GPU peer-to-peer transfer bandwidth

The next step is to connect SR-IOV virtual functions to the Windows host, and PAX provides such functions as standard physical NVM devices so that the host can use standard NVMe drivers. After that, the virtual function will be combined with the Linux host, and the new NVMe device will appear in the list of module devices. The result of this experiment is that both hosts can now use their virtual functions independently.

It is important to note that the virtual PCIe fabric and all dynamic allocation operations are presented to the host in a fully PCIe-compliant manner so that the host can use standard drivers. The embedded switch fabric firmware provides a simple management interface so that the PCIe fabric can be configured and managed by an inexpensive external processor. Device peer-to-peer transactions are enabled by default and require no additional configuration or management by an external fabric manager.

Summarize

The PCIe switch fabric fabric is an excellent way to take full advantage of the enormous power of a CPU, but the PCIe standard itself has some hurdles. However, these challenges can be addressed by using dynamic partitioning and multi-host single-root I/O virtualization sharing techniques so that GPU and NVMe resources can be dynamically allocated in real-time to any host in a multi-host system to keep up with machine learning workloads changing needs.

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Gas assisted chair mold solution

 

Gas assisted molding is widely used in manufacturing hollow plastic parts, light weight but strong strength. Especially for chair mold, then how to manufacture good quality gas assisted chair mould?

First the material used. Here are three solutions:
1. pure PP
2. PP plus filler (calcium carbonate)
3. PP plus glass fiber
If go first way, it is very easy to cause shrinkage, as chair corner part is very thick.
If go second, chair appearance will be polisher than with fiber.
But usually we suggest the last, and go PP + 15% glass fiber. Although chair part can not be same polish as the second because of fiber special specification, but it is easier to blow gas. Besides, it has more strength and tenacity.

Before chair mould design, need to have mold flow analysis to better understand material flow, gas blowing channel and all related issues. And suggest valve gate system, compared to normal hot runner, it can completely solve mould flash during air blowing.

If you have new project of gas assisted chair mold, kindly tell below information, and we’ll supply you fine solution of gas assist chair mould:

  • Chair part dimension & weight
  • Suitable injection molding machine
  • Air pressure of gas assisted equipment
  • Do you prefer fully automatic manufacturing with robot? Or auto drop without robot?

 

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How Does a Small Anchor Hold an Aircraft Carrier?

Whether it is an aircraft carrier, a warship or a giant ship, the principle of the anchor fixing is the same. This is similar to a fishhook. You can imagine that a small fisher bone weighing about 0.2 grams can catch 2 kilograms of fish, is it just done by the hook itself? Obviously not, because the hook is hooked into the fish, the fish has a lot of resistance and pull on the hook, and the fish is caught. The anchor has anchor claws, and after the anchor bottoms, the anchor claw will bite into the soil under the tension of the anchor chain and gravity. The resistance of the soil to the anchor will fix the anchor. When the ship is anchored, not only the anchor acts, but also the anchor chain is very important. The total weight of the anchor chain is much larger than the anchor. When anchoring, the length of the anchor chain is several times that of the water depth. After the anchor, there is a long anchor chain lying on the bottom of the water. The bottom of the water also has a large frictional resistance to the anchor chain.


The anchor chain not only transmits the pulling force of the anchor, but also plays the role of absorbing the dynamic load of the hull and balancing the external force of the ship. When the ship is blown by the wind or waves away from the anchoring point, the chain will be tightened. The original anchor chain will be pulled up and stretched, and the weight of the chain itself will also fall, countering the tension and giving the boat. A “pull back” force. The heavier the anchor chain, the greater the inertia and the stronger the ability to resist external loads. The longer and heavier the anchor chain, the shallower the water and the greater the pulling force. Of course, sometimes when the wind is particularly large, the pulling force will not be enough, and it will be dragging. At this time, you should enter the port or shelter the navigation area to avoid the wind. 

People who have watched the Pirates of the Caribbean must ask, in order not to enter the death triangle, the Black Pearl has quickly dropped the anchor into the sea to make a quick turn. The sea is so deep, may the anchor chain be so long? 

After all, science fiction movies are just science fiction movies. It is meaningless to stop the ship in deep water first. The ship stop is usually the anchorage and dock before entering the port. The anchorage water is relatively shallow, generally relying on anchoring and mooring, and the way of docking the dock is to carry the cable (the bow cable and the stern cable). If the deep water area wants to stabilize the ship’s attitude, it can only rely on the engine to retreat the propeller top flow direction. Some ships have good maneuverability, and there are also bow thruster, stern thruster and other side thruster. 

If you stop the boat in the Mariana Trench, you need more than 10,000 meters of chain, do you think it is possible? Before the anchoring, the captain can know the depth of the sea in the anchor zone, which is generally not too deep. The ship determines the length of the anchor chain according to the depth of the seawater. If you have to stop the ship in the deep sea area, there is no need to anchor and you can float. Use the stern main propeller and the bow side thrust to achieve the maneuvering of the ship! 

If you unfortunately hook the rock during the anchoring process and can’t pull it up, you can only abandon the anchor and go, but generally this does not happen, because the radar is used to determine the seabed before anchoring, even so, Every year, the sea liner loses the anchor for some special reasons!

If you drop the hook when you hit the anchor, what should you do? This situation generally does not happen, but it does not rule out the possibility. Generally, first throw three to four anchor chains to stop the cat chain, observe whether there is a rebound after the anchor chain is tightened to determine whether to hook the bottom of the sea and then send the anchor chain to increase the friction between the anchor chain and the seabed, if not hooked The bottom of the sea will be anchored again. 


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Annette X.//SMC Editor


Guest contributors are welcome at the Alloy Wiki.It is a weekly wiki and guide on alloy information and processing technology, while also about the vast array of opportunities that are present in manufacturing. Our team of writers consists of a Machining Material Supplier / Machinist / Tool and Die Maker, a Biomedical Engineer / Product Development Engineer, a Job Development Coordinator / Adjunct Professor, and a President and CEO of a manufacturing facility.

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Reasonable use is very important. Car lighting modification has skills

The eyes are the windows of the human soul, and for a car, the headlights are like human eyes. Bright eyes can allow us to receive image information more clearly. And good headlights can improve driving safety at night, making it easier and more comfortable for drivers to drive at night. However, due to production costs and other reasons, many models currently use more traditional lensless halogen headlights when they leave the factory. There is a big gap between the performance of this headlight and the xenon headlights or even the LED light source headlights. .

Based on car owners’ dissatisfaction with the performance of the original car lights, refitting headlights has naturally become a popular refitting project in the refitting market, but the knowledge and key points involved are not known to most people. Wrong modification and use will not only fail to get the desired effect, but also harm others and ourselves. Today, we will talk about what to know and pay attention to when modifying headlights.

Let me first talk about our *common halogen lamp modification xenon lamp case. The reason for the modification is that the light-emitting principle of the halogen bulb is the same as the light bulb used in our home. It relies on the use of tungsten wire to emit light, but it is limited to tungsten. The filament itself cannot withstand high temperatures. Considering its melting point, most of the original bulbs are usually set at 60W, and 60W bulbs can only emit 1000 lumens. If they are converted into 100W bulbs, it will be 1200 lumens at most. ! To increase its lumen, it needs to be updated with new luminescent materials! But limited to the limitations of the car’s own electrical system, if the wattage of the bulb is increased, it will have a lot of negative effects on the car! The emergence of xenon headlights solves the problem of insufficient brightness of car headlights. The lumens of up to 3000 lumens make the brightness of the light significantly higher than that of traditional halogen headlights.

☆ Tips: What is lumen?

Lumen is the transliteration of English Lumen, abbreviated as lm, which is a measurement unit of luminous intensity, which refers to the luminous flux emitted by a light source in a unit solid angle in a specified direction. The specific measurement is not introduced here. Interested car owners can understand that, everyone only needs to remember that the greater the lumens, the higher the luminous intensity.

● Modification of xenon headlights:

Xenon headlamps are different from traditional halogen lamps. They rely on inert gas to emit light. They are also called high-intensity discharge gas lamps, or HID (Intensity Discharge Lamp) for short. The xenon lamp breaks the tungsten filament luminescence principle invented by Edison. The quartz tube is filled with high-pressure inert gas—Xenon (xenon) to replace the traditional filament. There are mercury and carbon compounds on the two-stage electrodes. The high-voltage current stimulates the xenon gas to emit light, forming a white arc between the two poles, and the emitted light has a higher color temperature.

PS: Although xenon headlights have been popular on the market for many years, many friends still pronounce xenon (xiān) gas as hernia (shàn) gas. Friends who read it wrong should not show their timidity again after reading the article!

Due to the different working principles, the basic assembly of the xenon headlight includes: a bulb, a stabilizer and a matching cable set. Naturally, the light bulb does not need to be explained, it is the main unit of light emission, and the color temperature and brightness depend on it. The stabilizer is a device that provides an instantaneous high voltage of 23000V when the bulb is driven. It also has the function of protecting the circuit from overload and controlling the driving current. At present, the quality of products from many cottages or small factories in China is uneven, and the problems mostly occur in the stabilizer, and the line of xenon lamp products whose quality cannot be guaranteed will also cause safety hazards to the vehicle. Wrong installation or use of inferior products can cause Vehicle spontaneous combustion accident. Therefore, in addition to the lighting effect, the quality and installation of the whole set of xenon headlights are very important.

The bulbs of the xenon headlights are different from the original halogen bulbs in appearance, and the focus point will also change accordingly. After replacing the xenon bulbs, the original lamp bowl cannot effectively condense the light, so the light usually appears The scattering state, in simple terms, means that you can’t see clearly inside the car. The outside of the car is very dazzling. Not only did you fail to get the desired effect, but it also caused a safety hazard to night driving. The lens is a powerful weapon to solve this problem.

The light intensity of    xenon lamp is very high, and the light scattering area is very large. If the lens is not installed, all the light is scattered around, whether it is lighting or safety is a problem (it is an absolute killer for the opponent car). After installing the lens, the light can be controlled, which can make the shape and directivity of the light more controllable. In addition, the lens is divided into single-lens and double-lens. The single-lens lens is designed with lenses corresponding to the low beam and the high beam (the separate light bulbs are used for the far and near beams). The difference between the double-lens lens is that it can make a conversion similar to the far and near beams. It is usually in the low beam state. When the high beam is turned on at the same time, it operates the dimming shutter through the electromagnetic mechanism, so that the light of the low beam is also allocated to the high beam.

☆ Tips for using xenon lamps: For those who use xenon headlights for high beams, one thing needs extra attention, that is, when the xenon lamps are not working (when the lights are not driven during the day), do not use the high beams in rapid succession. Lights (many people have this habit when overtaking or reminding other vehicles to pay attention to pedestrians). This will not only fail to achieve the brightness of the xenon lamp, because the xenon lamp stabilizer will take a few seconds to enter the normal working state. , Such a long-term operation will make the stabilizer in the xenon headlight reimbursement in advance.

In addition, a modified bulb called golden eye is still popular on the market. Several common brands such as Philips and Osram have also introduced golden eye in the form of halogen and xenon lamps. The halogen lamp is electroplated on a white glass bulb. A layer of golden yellow substance, after the light passes through, it will show a golden yellow light. The xenon lamp changes the color of the light by changing the electrode, so it is called the golden eye. This kind of light has better penetrating power in foggy weather, can make the light shine farther, but it is usually more dazzling, it is recommended to be used as a fog light or high beam light.

☆ Misunderstanding of color temperature

The color temperature is a general indicator that indicates the spectral quality of the light source. The color temperature is defined as an absolute black body. When the radiation of the light source in the visible region is exactly the same as that of the absolute black body, the temperature of the black body at this time is called the color temperature of the light source. The characteristic of the low color temperature light source is that in the energy distribution, red radiation is relatively more, usually called “warm light”; when the color temperature is increased, the energy distribution is concentrated, and the proportion of blue radiation increases, usually called “cold light”. The color temperature of some common light sources is: standard candlelight is 1930K (Kelvin temperature unit); tungsten lamp is 2760-2900K; fluorescent lamp is 3000K; flash is 3800K; noon sunlight is 5600K; electronic flash is 6000K; blue sky is 12000-18000K.

Having said so much, maybe you look a little confused, it doesn’t matter, you just need to remember the following key points about color temperature: color temperature is not a unit representing brightness, which means that color temperature has nothing to do with brightness. On the other hand, if the color temperature is too high, it will appear bluish (higher will appear purple). The light with this color temperature has poor penetration in haze weather, so when choosing xenon headlights, never choose too high color temperature. Products (the xenon headlights with extremely high color temperature are mostly fake and inferior products, so buying genuine products from major manufacturers can also eliminate this problem).

● Visual system lighting modification

In addition to making the headlights of your car brighter and easier to use, personalized modification is also the most popular car lamp modification project at present. I believe that friends who pay attention to appearance modification must be no strangers to angel eyes and LED width lights, compared with far and near beam headlights. Modification, the lighting modification that plays a decorative and beautiful role has become a very popular modification project in the current domestic modification market.

☆ Angel eyes

There is a saying among the folks that if you install a lens without angel eyes, you can’t help yourself. This thing is like a finishing touch. If you don’t add it, it’s like a woman without makeup (maybe more appropriate contact lenses) and cannot highlight you. The charm of the pupil! Although a bit exaggerated, it is enough to prove the popularity of angel eyes.

In fact, the so-called angel eyes are the unique headlight design of BMW brand models. The yellow or other colors of the halo composed of LED lights surrounding the low beam and high beam heads are very beautiful in the width light state. *It comes from the design of BMW 5 Series headlights. When the headlights are turned on, the BMW headlights will have a halo. This halo is very similar to the halo on the head of an angel, so many users gave her a nickname: Angel Eyes.

Speaking of angel eyes, I have to mention the *recently emerging demon eyes. In fact, the light source and structure of the demon eyes and angel eyes are similar, but they are installed in the lens to achieve different visual effects. In the final analysis, angel eye modification is nothing more than the personalized appearance of the vehicle. In the modification, we should pay more attention to the product quality and installation links. All products that involve the modification of the vehicle circuit must not be hastily, so as not to bring safety due to small mistakes. Hidden dangers. At present, the quality of angel eye modification is uneven. Many car owners have encountered burnout after modification, and the lampshade needs to be disassembled for repair and installation, which is relatively troublesome, and the craftsmanship of the technician will directly affect * The final quality.

☆ LED decorative lights

In recent years, LED technology has been used by brands such as Audi and Lexus as lighting headlights. However, due to the constraints of technology and cost, LED lights are only used as personalized decorative car lights in the refitting market (compared to headlight refitting, taillights are more commonly used). For extensive). When it comes to automotive LED lights, the most representative one is the Audi brand. In recent years, Audi has been committed to the research and development of LED light source technology, and has now used LEDs in its mass-produced models (R8, A8, etc.). It’s just that compared to the LED headlights used in the expensive Audi A8, the current modified products do not have so many high-tech smart technologies. The decorative effect has naturally become the main theme of the modified LED. The domestic LED modification is as applicable as the angel eye headlights. For various models, LED light sources are different in wider application features, such as fog lamp decoration, car logo decoration, taillights, interior lights, etc.

Final Thoughts

☆ Pay attention to the brand and quality of the modified headlights:

At present, there are many kinds of refitting parts for car headlights, and the price difference is huge. The car headlights are mixed, especially the car headlights are directly related to the personal safety of driving at night, so you must be careful when choosing them. The more common halogen bulbs are available from a pair of RMB 30 to a pair of RMB 400. The bad brand-name bulbs not only have low brightness and limited life, but may also burn out the circuit. From the perspective of HID xenon headlights, the price difference between different brands is also obvious. Because HID xenon headlights are parts with very complicated crafts and technologies, bad HIDs often have a short lifespan, and stabilizers and bulbs are easy to burn. In addition, the color temperature, brightness and scattering angle often do not meet the requirements, so it is best to choose well-known products from large manufacturers, such as Osram, HELLA, Philips, Mì, etc., so as not to be too greedy for small things.

☆ Modified headlights must be based on safety

Some car owners who have changed their HID lights often arouse passersby’s disgust. On the one hand, some people choose HIDs with a high color temperature and a bluish color in order to be cooler. Then this blue light will particularly irritate the other passersby and drivers. His eyes are not only unpleasant, but also affect safety; on the other hand, many car owners do not pay attention to the rules of using lights when driving at night, such as turning on the high beam when the vehicle is wrong, flashing the lights randomly, and so on. In fact, there are many regulations and restrictions on car headlights overseas, especially xenon headlights, which have clear regulations on their color temperature, brightness and angle. Although the current domestic regulations in this area are not complete, we should also choose modified HIDs that comply with overseas safety regulations, because these regulations are formulated in accordance with the bottom line requirements of safe driving, and you should not make fun of your own lives.

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What is the pipeline pressure rating

Pipeline pressure grade
Pressure piping components are generally standard parts, so the design of pressure piping components is mainly the selection of its standard parts, and the determination of pipeline pressure grade is also the determination of its standard part grade.
The pressure rating of the pipeline consists of two parts:
the nominal pressure rating
of the standard pipe fittings expressed in nominal pressure; the wall thickness grade of the standard pipe fittings expressed in the wall thickness grade.
Pipeline pressure rating: Usually, the parameter that reflects the pressure characteristics of the pipeline, which is determined by the nominal pressure rating and wall thickness rating of the standard pipe fittings in the pipeline, is called the pipeline pressure rating. In order to simplify the description, it is customary to refer to the nominal pressure rating of the pipe fittings as the pressure rating of the pipeline.
The determination of the pressure level is the foundation and the core of the design of pressure piping. It is the design prerequisite for pressure pipeline layout and pressure pipeline stress check, and it is also an important factor that affects pressure pipeline infrastructure investment and pipeline reliability.
5.1 Design conditions In
engineering, process operating parameters should not be directly used as design conditions for pressure pipelines. Factors such as fluctuations in process operations, the impact of connected equipment, and environmental impacts should be considered, and a certain safety margin should be given on the basis of process operating parameters. Quantity as a design condition. The design conditions mentioned here mainly refer to the design pressure and design temperature.
The design pressure of the pipeline: should not be lower than the pressure under the most severe conditions composed of internal pressure (or external pressure) and temperature during normal operation.
The most severe conditions: refer to the conditions that lead to the maximum wall thickness or the highest nominal pressure level of pipes and piping components.
Design pressure determination: Considering the influence of factors such as the hydrostatic column pressure of the medium, the design pressure should generally be slightly higher than the maximum working pressure under the most severe conditions composed of (or) external pressure and temperature.
a. Under normal circumstances, the design pressure of piping components is determined
. Under normal circumstances, in order to facilitate the operation, it is advisable to adopt the method of pressure vessel, that is, to increase a margin factor on the basis of the corresponding working pressure.

    ※ When the design pressure determined according to this principle will cause changes in the pipeline pressure level, it should be judged whether the working pressure is the highest working pressure under the most severe conditions composed of internal pressure (or external pressure) and temperature. If so, please report With the approval of the relevant technical person in charge, the design pressure can be the highest working pressure at this time without adding a coefficient. b. When there is a safety relief device in the
pipeline, and when there is a safety relief device in the pipeline, it indicates that the pipeline may exceed its normal operating pressure during operation. The purpose of setting up safety pressure relief devices (such as safety valves, bursting discs, etc.) is to automatically release the pressure when the system exceeds its normal operating pressure so that the hardware of the equipment, pipelines and other systems can be protected. At this time, the design pressure of the pipeline should not be lower than the set pressure of the safety relief device.
c. High-lift pumps in the pipeline.
For high-lift pumps, especially reciprocating pumps, a relatively high sealing pressure is often generated in the pipeline and pump before the first shut-off valve within a short time of starting. Sometimes this sealing pressure will reach a very large value. At this time, the design pressure of the outlet pipe of the pump should be the maximum closed pressure of the pump.
D. The pressure of the
vacuum system piping of the vacuum system is its external atmospheric pressure, so its design pressure should be 0.1MPa external pressure;
e. The piping connected to towers or vessels and other equipment

The design pressure of the piping connected to towers or vessels and other equipment should not be lower than the design pressure of the connected equipment. When there is a higher liquid column in the pipeline, the influence of the hydrostatic head should also be considered. In fact, for the pipeline, its force is more complicated than that of the equipment. This is because in addition to the medium load, it also often suffers from the piping forces caused by the thermal expansion and contraction of the pipeline. Therefore, the design pressure of the pipeline should generally not be lower than the design pressure of the equipment.

5.1.2 Design temperature

The design temperature of the pipeline: It should not be lower than the temperature under the most severe conditions composed of internal pressure (or external pressure) and temperature during normal operation.

The most severe conditions: Refers to the conditions that lead to the maximum wall thickness, the highest nominal pressure level, or the highest material level of pipes and piping components.

Determination of design temperature: Considering the influence of factors such as environment, heat insulation, operation stability, etc., the design temperature should be slightly higher than the maximum operating temperature under the harshest conditions composed of internal pressure (or external pressure) and temperature.

a. Under normal circumstances, the design temperature of piping components is determined

In general, in order to facilitate the operation, we might as well adopt the method of pressure vessel, and increase a margin factor (except flanges and bolts) on the basis of the corresponding working temperature.

※When the design temperature determined in accordance with this principle will cause changes in the pipeline pressure level or material, it should be judged whether the operating temperature is 
  the highest operating temperature under the most severe conditions composed of internal pressure (or external pressure) and temperature. If it is, In the case of requesting the approval of the relevant technical person in charge, the design temperature can be the highest working temperature at this time without adding a factor.
The design temperature of flanges and gaskets
should not be lower than 90% of the maximum working temperature; the design temperature of bolts and nuts should not be lower than 80% of the maximum working temperature.
b. Jacketed or external heat tracing pipeline.
For jacketed or externally heated pipelines, when the temperature of the process medium is higher than the temperature of the heat tracing medium, the design temperature is selected according to the above table; when the temperature of the process medium is lower than the temperature of the heat tracing medium, a jacket for heating the heat medium temperature is taken with the design temperature, and then take the external heating medium heating temperature minus 10 deg.] C with a larger value of both the design temperature process temperature;
. C pipeline safety relief
safety relief The highest or lowest temperature that may occur when the pipeline is discharged is the design temperature;
d. The steam-purged pipeline
adopts steam-purged pipelines. When the temperature of the medium is higher than the temperature of the purged steam, the design should be determined according to the medium temperature according to the above table temperature. When the temperature of the medium is lower than the temperature of the purge steam, it should be determined according to the specific situation. For example, when the pipes and components selected according to the temperature of the medium cannot withstand the conditions of the purging medium, the grade should be appropriately increased to adapt to the conditions of the purging medium.

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Why People Use Aluminum Composite Panel On Building Outer Wall?

Steel is the most common metal in the construction industry. In steel, aluminum has become the most popular material. Many building structures used aluminum 

windows, aluminum partitions, scaffolding and more. With the invention of the aluminum composite sheet, they also began to coat with aluminum sheets. In simple 

terms, acp sheet cladding would entail the fitting of aluminum panels to the exteriors of a building to enhance its beauty and durability as well.

There are many advantages to using an aluminum composite panel cladding process. We will give examples below.

Aluminum is famous for its durability. It can withstand various weather changes such as extreme heat, cold, rain. It is corrosion-proof and fireproof. Aluminum panels 

can also be protected from the adverse effects of ultraviolet rays. Therefore, these aluminum composite panels have a long service life.

Today the aluminum composite panel found in the facade of the roofing is anodized panel. You can paint these panels in various colors. Therefore, these panels also 

have a large decorative effect. Due to the water resistance of the aluminum, cleaning of the panel is also easy.

These aluminum composite panels can reflect light in a very efficient way. Therefore, you can also use the cladding process for interior wall and temporary ceiling.


Aluminum does not burn. Therefore, these aluminum composite panels are refractory. However, at temperatures above 650 degrees Celsius, aluminum may melt. 

Nevertheless, they do not emit unpleasant smoke and gas. Therefore, it is safe from the viewpoint of environmental protection.

The aluminum composite panel cladding is very lightweight. This is the greatest advantage of these panels. Therefore, from the viewpoint of durability and decoration, 

these panels are very useful as cladding materials.


This explains the growth of popularization of aluminum composite panel cladding on building outer wall.

For our full list of products that we offer check out our website here. Be sure to join the conversation in our LinkedIn groupFacebook, and Twitter. Try also our WeChat by scanning the QR code below.

Susan F.//SMC Editor

Guest contributors are welcome at the Alloy Wiki.It is a weekly wiki and guide on alloy information and processing technology, while also about the vast array of opportunities that are present in manufacturing. Our team of writers consists of a Machining Material Supplier / Machinist / Tool and Die Maker, a Biomedical Engineer / Product Development Engineer, a Job Development Coordinator / Adjunct Professor, and a President and CEO of a manufacturing facility.

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Cloudflare ditches Intel Xeon processors for AMD EPYC

In the server processor market, AMD’s goal this year is to occupy at least 10% of the share, which is not difficult, because the EPYC 7002 series of the 7nm Zen2 architecture is constantly bringing customers to AMD. Today Cloudflare announced that their 10th Gen blade servers are fully moving to AMD’s EPYC processors.

Cloudflare is a network service provider, established in 2009, mainly provides CDN and DNS services. As of February 2020, it has built data centers in more than 200 cities in more than 90 countries around the world, and 1 billion IP addresses flow through them every day. 1100 HTTP requests per second, 95% of global connections can be completed in 100 milliseconds.

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare’s servers have been Intel Xeons for 10 years, which was no problem before, but on the 10th generation blade servers they abandoned their old partners and moved to AMD’s EPYC processors, and this generation of servers does not have any Intel components , There are no Intel components on the CPU, motherboard, memory, storage and network interfaces, which are very rare in the industry.

Cloudflare ditches Intel Xeon processors for AMD EPYC

They listed the configuration options of their blade servers in recent years. In 2015, they used a dual-socket 8-core Xeon E5-2630 v3, and then they used a dual-socket Xeon Platinum 6162, 2×24 cores for the ninth-generation blade server. , 2x150W TDP.

Cloudflare ditches Intel Xeon processors for AMD EPYC

AMD’s EPYC 7642 processor was selected for the tenth generation blade server, which is a 48-core 96-thread processor. They initially considered 64-core EPYC, but after testing, they found that the performance improvement was not so high, and finally gave up 64-core product.

Even so, the 48-core EPYC 7642 can still test single-channel to achieve the previous dual-channel effect, and the cache, memory, PCIe channels and other aspects are better, and the TDP power consumption is 75W lower, which is equivalent to reducing the TDP per core. 25%.

Cloudflare ditches Intel Xeon processors for AMD EPYC

As for why the AMD EPYC processor was chosen, the test results they published can explain the problem.

Cloudflare ditches Intel Xeon processors for AMD EPYC

The detailed evaluation is below, but this table summarizes the performance comparison between the EPYC 7642 and the dual-socket Xeon Platinum 6162. It can be seen that AMD leads the performance by as little as 27%, and as much as 50%.

Of course, the most suspenseful thing is the price. Cloudflare has not announced the specific price. It is estimated that the purchase price is not easy to say. This is a trade secret. But from the public quotation, EPYC 7642 is $5,885, Xeon Platinum 6162 is $3,115, and 2 pieces cost $6,230.

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

Cloudflare ditches Intel Xeon processors for AMD EPYC

The Links:   LTM150XO-L01 7MBR10SA120-50 FF200R12KE3

Is the good development prospect of the CNC machining industry?

We have said a lot about the functions of Dongguan Precision Machining. Dongguan Precision Machining can bring a lot of help to people in many uses.
So no matter which kind of main product or auxiliary product production tool is good, in fact, it is said that pay attention to the brand. Many Dongguan precision machining processes need to establish a brand and advertise by themselves, then the popularity in the market will gradually increase. Well, our Dongguan Precision Machining is the same.
 As a production product that can also be said to be an auxiliary product, it is itself a brand and it is also necessary for these manufacturers to advertise these products. Therefore, Dongguan precision machining is well known in the market.
For more information, welcome to find website: www.ptjmachining.comPrevious: cnc machining parts are the link we must pay attentionNext: Data is very important when CNC machining

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Arrival query module of auto parts information management system

 

Arrival inquiry can be inquired by product number, product name, unit number, unit name and arrival date. Inventory management module This module completes the inquiry of inventory, mainly including inquiry by voucher number, inquiry by product number and inquiry by product name. Sales Management Module This module is composed of three independent modules: product sales, sales order query, and sales detail general ledger. It can input, query, statistical analysis and report printing of sales data. Product sales perform sales data entry, printing receipts and other tasks.

Sales Order Inquiry Complete inquiry of previous sales orders, you can inquire by customer number and customer name. The sales details general ledger queries and displays the sales status of all commodities, and can also display the sales status of a certain commodity. The customer management module manages all suppliers and users, including 4 sub-modules: supplier files, user files, supplier information and user information modules. The provider file module enters, modifies and queries the provider records. The user profile module enters, modifies and queries user records. The offerer information module browses for arrivals, additional payments, and additional payments for the offerers. The user information module allows users to browse sales, additional payments, and additional payments.

Return processing module The main function of this module is to query the return status of all users and suppliers, including the supplier return module and the user module. Out-of-stock processing module The main function of this module is to inquire and print the goods below the minimum storage capacity, so as to purchase goods in time. Print module This module completes the printing of commodity quotations, year-end inventory lists, warehousing lists, sales detailed lists, inventory shortage status lists, and annual and monthly reports.

For automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Hot Sale Funny Cute Flower Shapes Candy Mold Tray

What can be a popular products?Or what is the possible product can meet with buyer's need?It is a question most manufacturers, suppliers and retailer be highly concerned about.An excellent product must has it's advantages which make buyers notice it. This silicone tray sold on our store, as  you can see, have a beautiful 3d flower shape cavities.It can help you to save your time through shaping 15 pieces chocolate or candy at one time.Besides, it is made of a material FDA approved can direct conntact with food, so it is safe to be used to shape chocolate and candy.What's more, this flower shapes candy mold tray be tested by our worker. It did not melt on a high temperature of 200 degree. And also had no odor after this silicone tray be took out from oven.And in a low degree, this silicone mold still showed its excellent ability of resistant to extreme temperature.In concludtion, this flower shape mold tray for making chocolate and candy is a qualified product.

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