A flange centering installation guide pin and method
By using guide pins during flange installation to control the alignment of bolt holes, the problem of high-precision installation of ceramic spray flange is solved, achieving higher alignment accuracy and protection of ceramic coating.
Patent Information
- Application Number
- CN202411745326.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-04-08
AI Technical Summary
The existing flange centering method cannot meet the high-precision installation requirements of ceramic spray flange, resulting in damage to the ceramic coating.
The guide pin is installed with a flange centering, and the guide pin is penetrated into the flange bolt hole to control the alignment of the bolt hole, and the installation alignment of the flange is indirectly controlled. The diameter of the guide pin is smaller than the diameter of the bolt hole. It is designed with three gap specifications: 0mm, 0.2mm and 0.4mm, which are used to match the tolerances of different bolt holes.
The installation centering accuracy of the flange is improved, the centering deviation is reduced, from ±4mm to ±0.85mm, and the damage to the ceramic coating is avoided. The method is compatible with commonly used bolt-assisted, shape-aligned and concave-convex groove centering methods.
Smart Images
Figure CN119778360A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a flange in the engineering field, and in particular to a flange centering installation guide pin and a method. Background Art
[0002] Flanges are widely used in engineering to connect pipelines, equipment, and structural parts. Various gaseous, liquid, and mixed media flow inside, some of which have high heat and high corrosion characteristics. And because there are pipelines, equipment, and structural parts on both sides of the flange, in most cases the alignment inside the flange cannot be directly observed and measured. There are three main flange alignment methods used in engineering now: The first is the bolt-assisted centering method, which means that the flange can be considered to be centered if the bolts around the flange can be freely inserted into the bolt holes. This method is the most commonly used because almost all flanges have bolt holes, but this method has a large error. Generally, the gap between the bolt and the bolt hole is 2mm, so the flange centering deviation can reach more than 4mm.
[0003] The second method is the flange shape alignment method. After the flange is installed, observe or measure the alignment of the two flange edges around. If the alignment is not much different around, the flange is considered to be well aligned. This method is also very common and has long been the most commonly used flange inspection method. However, for situations where the two flange edges are far apart, such as CB587, CB537, and CB898 high-pressure valve flanges, the effect is very unsatisfactory.
[0004] The third method is the flange concave and convex groove alignment method. Some flanges are installed with concave and convex grooves. When the concave and convex grooves are inserted, the flange alignment is considered good. When the flange is installed using this method, the edges of the concave and convex grooves will inevitably touch each other.
[0005] However, the inventors of this application found that the above technology has at least the following technical problems in the process of implementing the technical solution of the invention in the embodiment of this application: In recent years, with the application of various coatings such as anti-corrosion and insulation, the concave and convex flanges with ceramic coatings sprayed on the sealing surface, such as the CB587 side valve flange and the CB537 cup-shaped pipe joint flange, hereinafter referred to as sprayed ceramic flanges, require that the inner and outer diameters of the two flange sealing surfaces be micro-contacted or non-contacted during installation to avoid damage to the ceramic coating during flange installation. The method of roughly aligning the bolts and the flange structure itself can no longer meet the installation accuracy requirements of sprayed ceramic flanges. Referring to the principle of bolt-assisted flange alignment, a flange high-precision alignment installation guide pin and method came into being. Summary of the invention
[0006] In order to solve the deficiencies in the prior art, the ceramic spray flange has low installation centering accuracy, and the edges of the flange concave and convex grooves contact and squeeze during installation, which ultimately causes damage to the ceramic coating on the edges of the flange concave and convex grooves. The embodiment of the present application provides a flange centering installation guide pin and method. The method controls the installation centering of the flange bolt hole by inserting the guide pin into the flange bolt hole, indirectly controls the flange installation centering, and solves the technical problem of damage to the ceramic coating of the ceramic spray flange.
[0007] The solution adopted by the embodiment of the present application to solve the technical problem is: A flange centering installation guide pin is a rigid pin shaft, the diameter of the guide pin is smaller than the diameter of the flange bolt hole, and the guide pin is designed to have three specifications of clearance of 0mm, 0.2mm, and 0.4mm according to the clearance with the theoretical value of the flange bolt hole; wherein, the design of the clearance of 0mm is in consideration of the manufacturing tolerance of the bolt hole, which is generally ±0.2mm. In this embodiment, the guide pin with a clearance of 0mm with the theoretical diameter of the flange bolt hole can be inserted into the bolt hole in actual engineering; In this embodiment, there are three sizes of guide pins, four of each size, for a total of twelve guide pins.
[0008] Each guide pin is machined from a single piece of brass bar stock.
[0009] One end of the guide pin is designed to be in the shape of a nut, and the other end is designed with a pin hole and equipped with a pin to prevent the guide pin from falling during use.
[0010] If the bolt hole diameters of a pair of flanges are different, the diameter of the guide pin within the corresponding length range should match the bolt hole diameters of the two respectively, and the guide pin should be inserted from the side with larger bolt hole diameter to the side with smaller bolt hole diameter when used.
[0011] The length of the guide pin should be greater than the sum of the thicknesses of the two flanges.
[0012] In order to further solve the technical problem to be solved by the embodiment of the present application, in a method for centering a flange and installing a guide pin provided in the embodiment of the present application, A flange centering installation method, using a guide pin, controlling the installation centering of the flange bolt hole by inserting the guide pin into the flange bolt hole, and indirectly controlling the installation centering of the flange; calculating the size of the guide pin by using the bolt hole diameter, flange thickness, bolt hole diameter processing tolerance, and bolt hole spacing processing tolerance data of the two matching flanges, and calculating the centering accuracy of the flange installed using the guide pin and the method, and improving the centering accuracy of the installed flange by using multiple guide pins, using guide pins of various specifications, and clarifying the installation order of the guide pins in up, down, left, and right. The following steps are involved: Step 1. Collect flange size information: Collect data on bolt hole diameter, flange thickness, bolt hole diameter machining tolerance, and bolt hole spacing machining tolerance of the two matching flanges; Step 2. Calculate the guide pin size: Calculate the guide pin size based on the bolt hole diameter and flange thickness of the paired flanges. The size is calculated based on the three specifications of 0mm, 0.2mm, and 0.4mm clearance with the flange bolt hole. Step 3. Calculate the flange centering accuracy after using the guide pin: The flange centering accuracy after using the guide pin is calculated based on the flange bolt hole diameter machining tolerance, bolt hole spacing machining tolerance, guide pin diameter tolerance, and the design clearance between the guide pin and the screw hole; the calculation method is shown in the table below:
[0013] Step 4. Processing guide pins: Each guide pin shall be machined from a bar stock made of brass; the diameter tolerance of the guide pin shall be ±0.1mm, and the rest shall be in accordance with 1804-m for unmarked dimension tolerances; there shall be permanent marks on the guide pins to briefly explain the applicable scope of the guide pins; four guide pins with clearances of 0mm, 0.2mm, and 0.4mm with flange bolt holes shall be processed to form a set of flange guide pin tooling; Step 5. Install the flange using the guide pins: Note that the flange should be slightly shaken when the guide pin is inserted into the bolt hole to align the bolt holes of the mating flange; note that the guide pins with smaller gaps should be used to insert the flange bolt holes in priority; if there is an angle between the flange surface and the horizontal plane, the four guide pins should be installed in the order of up, down, left and right; the guide pins should be arranged evenly; at least two guide pins should be inserted to assist in the installation, otherwise replace them with guide pins with larger gaps; unless the subsequent guide pins cannot be inserted, use four guide pins to assist in the installation of the side valve; properly tighten the fasteners of the remaining bolt holes, and after the mating flange is firmly fixed, remove the guide pins and install the fasteners in turn.
[0014] Positive effects: The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages: 1. A flange centering installation guide pin and method are compatible with the previously commonly used bolt-assisted centering method, flange shape centering method, and flange concave-convex groove centering method. A flange installed using a flange centering installation guide pin and method can continue to use the previously commonly used method to check the flange installation centering result.
[0015] 2. A flange centering guide pin and method has higher centering accuracy than the flange installed by the bolt-assisted centering method, and the centering deviation is reduced from ±4mm of the bolt-assisted centering method to ±0.85mm in this embodiment. It can be understood that the accuracy range controlled by the flange centering guide pin and method is not static. By improving the manufacturing accuracy of the flange and the guide pin, the centering accuracy of the flange installed by the flange centering guide pin and method can be effectively improved.
[0016] 3. A flange centering installation guide pin and method are more applicable than the flange shape centering method. The flange shape centering method is not very effective for the situation where the distance between the two flange edges is far, such as CB587, CB537, CB898 high-pressure valve flanges. However, the use of a flange centering installation guide pin and method can effectively control the installation centering accuracy of such flanges.
[0017] 4. A flange centering installation guide pin and method can achieve a damage-free installation result for the flange sealing surface. When the flange is installed using the concave-convex groove centering method, the edges of the concave-convex groove will inevitably come into contact. After the contact, extrusion damage will occur during the tightening process of the flange fasteners. Using a flange centering installation guide pin and method to install the flange can theoretically achieve a contactless installation and avoid damage to the sealing surface during the flange installation process. It is understandable that a flange centering installation guide pin and method can also be used on other flanges that require high-precision centering installation, including but not limited to ceramic spray flanges.
[0018] 5. A flange centering installation guide pin has a simple and light structure, and the use method does not affect the normal flange installation speed. It can even play an auxiliary lifting role for large and heavy flanges, thereby increasing the flange installation speed. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0020] Figure 1 This is a schematic diagram of the guide pin structure of this embodiment; Figure 2 This is a schematic diagram of the guide pin assembly of this embodiment; Figure 3 This is a schematic diagram of the flange concave and convex groove assembly.
[0021] In the figure, 1. guide pin, 2. pin, 3. CB58 convex groove flange, 4. CB537 groove flange, 5. flange sealing gasket, J1. inner diameter edge of flange boss, J2. inner diameter edge of flange groove, J3. outer diameter edge of flange boss, J4. outer diameter edge of flange groove. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Although the embodiments of the present invention have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention.
[0023] The embodiments of the present application are further described in detail in combination with the CB 587 side valve and the CB537 cup-shaped pipe joint.
[0024] The method for making and using the guide pin 1 in this example is as follows: 1. Determination of the size of the guide pin 1 This embodiment only clarifies the size requirements of the guide pins used in the CB587 side valves and CB537 cup-shaped pipe joints in this embodiment, and in this example, in order to achieve a certain engineering purpose, the diameters of the bolt holes of all CB587 side valves are enlarged by 2mm. The guide pin sizes of other standard specifications of side valves and cup-shaped pipe joints should be implemented according to actual conditions.
[0025] 1.1 Statistics of side valves and cup-type pipe joints According to CB587 and CB537, the bolt hole size table of side valves and cup-type pipe joints is as follows: Table 1 Bolt hole dimensions for side valves and cup-shaped pipe joints, unit: mm:
[0026] 1.2 Calculation of guide pin dimensions The size of the guide pin should comply with the requirements of the following figure and Table 2. The guide pin size conversion method is as follows: D1 = side valve bolt hole diameter - clearance value D2 = cup-type pipe joint bolt hole diameter - clearance value L1 = side valve flange thickness L2 = cup-shaped pipe flange thickness + 10mm Table 2 Guide pin dimensions (unit: mm)
[0027] 2. Technical requirements for guide pins 2.1 The guide pin should be made of brass or carbon steel with strength higher than Q235B.
[0028] 2.2 The diameter tolerance of the guide pin is ±0.1mm, and the rest shall be in accordance with 1804-m for unmarked dimension tolerances.
[0029] 2.3 The guide pin diameter should be measured before each use. If it is out of tolerance, a new guide pin should be replaced.
[0030] 2.4 Marking example: For DN50 side valves, the guide pin with a clearance of 0.2 mm should be marked as DN50-0.2.
[0031] 2.5 Each guide pin should be stamped with a mark on the nut.
[0032] 3. How to use the guide pin During the installation of the ceramic spray side valve, 2 to 4 guide pins are used to assist the side valve in centering. The specific method is: 3.1 Prepare a set of side valve guide pin tooling with four guide pins of each specification, each with a clearance of 0mm, 0.2mm and 0.4mm from the bolt hole diameter of the side valve.
[0033] 3.2 When installing the corresponding specification side valve, use two to four guide pins to assist the side valve in centering installation. Note that the guide pins with smaller clearances should be used to penetrate the side valve and cup-type pipe joint bolt holes in turn. The first two guide pins should be arranged on the upper and lower sides as much as possible, and the guide pins should be arranged as evenly as possible.
[0034] 3.3 Unless the subsequent guide pins cannot be inserted, four guide pins should be used to assist the installation of the side valve.
[0035] 3.4 Tighten the remaining bolt holes appropriately. After the side valve and the cup-type pipe joint are firmly fixed, remove the guide pins and install the fasteners in turn.
[0036] 4 The tolerance range of guide pin control is shown in the following table (unit: mm):
[0037] Note: The final control accuracy of the guide pin can be effectively improved by improving the machining accuracy of the flange and guide pin.
[0038] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A flange centering guide pin, characterized by: The guide pin (1) is a rigid pin shaft. The diameter of the guide pin (1) is smaller than the diameter of the flange bolt hole. The guide pin (1) is designed to have three specifications of clearance of 0 mm, 0.2 mm, and 0.4 mm according to the theoretical value of the clearance between the guide pin (1) and the flange bolt hole. Three types of guide pins (1), four of each type, a total of twelve guide pins; Each guide pin (1) is integrally machined from a bar stock, and the bar stock is made of brass; One end of the guide pin (1) is designed to be in the shape of a nut, and the other end is designed with a pin hole and equipped with a pin (2); If the bolt hole diameters of a pair of flanges are different, the diameter of the guide pin (1) within the corresponding length range should match the bolt hole diameters of the two flanges, and the guide pin (1) should be inserted from the side with the larger bolt hole diameter to the side with the smaller bolt hole diameter when in use; The length of the guide pin (1) should be greater than the sum of the thicknesses of the two flanges.
2. A method for centering a flange, characterized in that: The guide pin (1) is applied to control the installation centering of the flange bolt hole by inserting the guide pin (1) into the flange bolt hole, thereby indirectly controlling the installation centering of the flange; the size of the guide pin (1) is calculated by the bolt hole diameter, flange thickness, bolt hole diameter machining tolerance, and bolt hole distance machining tolerance data of the two matching flanges, and the centering accuracy of the flange installed using the guide pin (1) and the method is calculated, and by using multiple guide pins (1) and guide pins (1) of various specifications, the installation order of the guide pins (1) is clarified to be up, down, left, and right; The following steps are involved: Step 1. Collect flange size information: Collect data on bolt hole diameter, flange thickness, bolt hole diameter machining tolerance, and bolt hole spacing machining tolerance of the two matching flanges; Step 2. Calculate the guide pin size: Calculate the guide pin size based on the bolt hole diameter and flange thickness of the mating flanges. The size is calculated based on the gap between the flange bolt hole and the guide pin: 0mm, 0.2mm, and 0.4mm. Step 3. Calculate the flange centering accuracy after using the guide pin (1): The flange centering accuracy after using the guide pin (1) is calculated based on the machining tolerance of the flange bolt hole diameter, the machining tolerance of the bolt hole spacing, the guide pin diameter tolerance, and the design clearance between the guide pin and the bolt hole; The calculation method is as follows: Bolt hole diameter tolerance ±: a; Bolt hole diameter tolerance ± b; Guide pin diameter ±: c; Design gap diameter between guide pin and screw hole: d; Flange centering accuracy ±: a+2b+c / 2+d / 2; Step 4. Processing guide pin (1): Each guide pin (1) is integrally machined from a bar stock made of brass; the diameter tolerance of the guide pin is ±0.1 mm, and the rest is in accordance with 1804-m for unmarked dimension tolerances; there are permanent marks on the guide pins to briefly explain the applicable scope of the guide pins; four guide pins each having a clearance of 0 mm, 0.2 mm, and 0.4 mm with the flange bolt hole diameter are respectively machined to form a set of flange guide pin tooling; Step 5. Install the flange using the guide pins (1): Note that when the guide pin (1) is inserted into the bolt hole, the flange should be slightly shaken to align the bolt holes of the mating flange. Note that the guide pins (1) with smaller clearance should be used to insert the flange bolt holes in priority. If there is an angle between the flange surface and the horizontal plane, the four guide pins (1) should be installed in the order of up, down, left and right. The guide pins (1) should be evenly arranged. At least two guide pins (1) should be inserted to assist installation, otherwise the guide pins (1) with larger clearance should be replaced. Unless the subsequent guide pins (1) cannot be inserted, four guide pins (1) should be used to assist the installation of the side valve. Tighten the fasteners of the remaining bolt holes. After the mating flange is firmly fixed, remove the guide pins (1) in turn and install the fasteners.