Electromagnetic flowmeter selection considerations

The selection of the electromagnetic flowmeter is best performed by technicians who are familiar with the on-site process conditions. The appropriate caliber can be selected according to the table of measurable flow ranges in the selection data. Material selection is best determined by the end user who is familiar with the on-site process conditions.

First, select the flow meter type:

1. Integral type and separation type Integral type and separation type each have advantages. The basic principle of selection is as follows: The separation type is generally used for requiring range selection, batch control, frequent or long-term soaking in water and other functions. It is also used in harsher applications, such as high-temperature fluids, vibration sources, and explosive environments. In most cases, both the integral type and the separate type can meet the use requirements.

2. The general type and explosion-proof type users determine whether to select the general type or explosion-proof type according to the flow meter use environment.

Second, the diameter of the sensor and the process of connecting the pipe diameter

In general, considering ease of installation, do not choose reducer. But the premise is that the flow rate in the flowmeter tube should be in the range of 0.3m/s to 10m/s. This option is often suitable for newly designed projects. When selecting the flow rate, it is necessary to consider the current work situation, but also consider the future situation when the equipment is running at full capacity. However, sometimes the sensor's diameter is not the same as the diameter of the connecting process pipe.

Such as:

1. The flow velocity in the pipeline is low, and the flow rate of the process is relatively stable. In order to meet the requirements of the flow range of the instrument, a flow rate is locally provided at the flowmeter, and the sensor aperture is selected to be smaller than the diameter of the process pipeline, and a different diameter tube is added before and after the sensor.

2. For large-caliber electromagnetic flowmeters, the larger the caliber, the higher the price, the lower the flow rate in the pipeline, and the stable process parameters, the smaller the diameter of the flowmeter, which not only makes the flowmeter run better In working conditions, it also reduces investment costs.

Three, straight pipe length D = flowmeter path

1. Do not install anything in the area near the flowtube that may interfere with the magnetic field, the inductive signal voltage, and the velocity of the flowmeter.

2. It is not necessary to use a straight pipe section at the downstream end of the flow meter. However, if downstream valves or other joints cause flow fluctuations, 2D to 3D straight sections must be used at the downstream end.

3. It is highly recommended to install the valve at the downstream end to avoid flow fluctuations in the flow tube and to avoid counting from the empty state.

Fourth, maintain a stable fluid conductivity

Avoid installing the flow meter in locations where fluid conductivity is not uniform. If chemicals are injected near the upstream end of the electromagnetic flowmeter, the flow rate may be affected. To avoid this situation, it is recommended that the chemical injection be changed to the downstream end of the flow meter. If it is necessary to inject from the upstream side, use a straight section (approximately 50D) long enough to ensure that the fluid and chemical mix thoroughly.

Fifth, the installation location:

1. The tubing must be completely filled with liquid. It is important to ensure that the pipe is always filled with liquid, otherwise the flow display will be affected and measurement errors will occur. The design of the road structure must ensure that the flow tube is always full of fluid. Vertical installation is recommended when the fluid is diverted or contains solid particles. However, when using vertical installation, mark the direction of the fluid from bottom to top to ensure that the piping is full of fluid.

2. Avoid air bubbles If air bubbles enter the tube, the flow display will be affected and measurement errors will occur. When the fluid contains air bubbles, the piping must be designed to prevent bubbles from accumulating in the flow tube.

If there is a valve near the flow tube, place the tube upstream of the valve as far as possible to avoid a decrease in the pressure inside the tube, thereby avoiding bubbles in the tube.

3. Installation direction: If the electrode is perpendicular to the ground, air bubbles that collect at the top or bottom can cause measurement errors. Install the junction box of the split flow tube and the integral converter on the top of the piping system to prevent water from entering.

4. It is recommended that gaskets be used between the flow tube and the user's flange, using compressed non-asbestos fiber gaskets, PTFE gaskets, or gaskets that are quite flexible. For GA, GC, and GD, use rubber gaskets or other fairly flexible gaskets (such as jacketed Teflon gaskets).

Six, electromagnetic flowmeter selection considerations

1. When ordering a separate measuring tube and/or a separate converter, please give the specific flow range, unit, pulse equivalent, cumulative display pulse equivalent, etc. Before delivery, these parameters are set in the assembled converter.

2. If there are some options, the technical specifications related to these options need to be written when ordering.

3. Tag numbers Each tag number can be described by 16 characters including letters (uppercase or lowercase), and the characters "-" and ".". If there are special requirements, the tag number can also be written on the nameplate and tag plate (if code SCT is selected). If the product is integrated, the tag number is also written to the converter memory. For the HART protocol, there can only be up to 8 characters. If the user wants to change only the settings stored in the converter's memory, define the software tag number. If there is no tag number, the corresponding product is not available at the time of delivery.

4. The value of flow range and unit flow range is limited to five digits (maximum 99999), which does not include the decimal point. The integrated AXF product is set to the first range in the forward direction. The separate measuring tube is also set to the first range in the forward direction of the converter (AXFA11 or AXFA14) assembled therewith. If no flow range and unit are specified, the relevant product is set to 1 m/s (3.3 ft/s) at delivery.

5. Output pulse equivalent If there is a special designation, the flow rate per pulse must be set. Otherwise, the relevant product is set to 0 pulse/sec.

6, the cumulative value shows the pulse equivalent

Engine Parts

Engine Block – This is the very core of the engine. Often made of aluminum or iron, it has several holes to contain the cylinders as well as provide water and oil flow paths to cool and lubricate the engine. Oil paths are narrower than the water flow paths. The engine block also houses the pistons, crankshaft, camshaft, and between four and twelve cylinders-depending on the vehicle, in a line, also known as inline, flat, or in the shape of a V.
Pistons – Are a cylindrical apparatus with a flat surface on top. The role of the piston is to transfer energy created from combustion to the crankshaft to propel the vehicle. Pistons travel up and down within the cylinder twice during each rotation of the crankshaft. Pistons on engines that rotate at 1250 RPM, will travel up and down 2500 times per minute. Inside the piston, lie piston rings that are made to help create compression and reduce the friction from the constant rubbing of the cylinder.
Crankshaft – The crankshaft is located in the lower section of the engine block, within the crankshaft journals (an area of the shaft that rests on the bearings). This keenly machined and balanced mechanism is connected to the pistons through the connecting rod. Similar to how a jack-in-the-box operates, the crankshaft turns the pistons up and down motion into a reciprocal motion, at engine speed.
Camshaft – Varying from vehicle to vehicle, the camshaft may either be located within the engine block or in the cylinder heads. Many modern vehicles have them in the cylinder heads, also known as Dual Overhead Camshaft (DOHC) or Single Overhead Camshaft (SOHC), and supported by a sequence of bearings that are lubricated in oil for longevity. The role of the camshaft is to regulate the timing of the opening and closing of valves and take the rotary motion from the crankshaft and transfer it to an up and down motion to control the movement of the lifters, moving the pushrods, rockers, and valves.
Cylinder Head – Attached to the engine through cylinder bolts, sealed with the head gasket. The cylinder head contains many items including the valve springs, valves, lifters, pushrods, rockers, and camshafts to control passageways that allow the flow of intake air into the cylinders during the intake stroke as well as exhaust passages that remove exhaust gases during the exhaust stroke.

Timing Belt/Chain – The camshaft and crankshafts are synchronized to ensure the precise timing in order for the engine to run properly. The belt is made of heavy-duty rubber with cogs to grasp the pulleys from the camshaft and crankshaft. The chain, similar to your bicycle chain wraps around pulleys with teeth.

With so many mechanisms performing many tasks at lightning speed, over time, parts may begin to wear causing your car to behave differently. Here are the most common engine problems and their associated symptoms:

Poor compression – Results in loss of power, misfiring, or no-start.
Cracked engine block – Causes overheating, smoke coming from exhaust, or coolant leaks, usually identified on the side of the engine.
Damaged Pistons, Rings, and/or Cylinders – Exhibit rattling sounds, blue smoke coming from the exhaust, rough idle, or a failed emissions test.
Broken or worn Rods, Bearings, & Pins – Cause tapping or ticking sounds, low oil pressure, metal shavings found in engine oil, or rattling upon acceleration.
Car engines may seem complicated, but their task is simple: to propel your vehicle forward. With so many components working together to create this motion, it`s imperative your vehicle receives proper maintenance to ensure their longevity. Regularly scheduled oil changes, fluid flushes, and changing belts and hoses at the recommended time is a great way to help prevent the unfortunate circumstance of a failed engine.

Cylinder liner Cylinder head gasket Piston Piston ring

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