Some standard content:
Setting of pipeline filters
HG/T20570.22-95
Compiled by: China Wuhuan Chemical Engineering Corporation Approved by: Ministry of Chemical Industry
Implementation date: September 1, 1996 Prepared by:
Wu Qiying of China Wuhuan Chemical Engineering Corporation
Reviewed by:
Wu Bingyong of China Wuhuan Chemical Engineering Corporation
Gong Renwei, Process System Design Technology Center of Ministry of Chemical Industry
1.0.1 Purpose of pipeline filters
Professional responsibilities
Pipeline filters are pipeline accessories for removing solid impurities from fluids. They are used to protect process equipment and special pipe fittings (such as compressors, pumps, fuel nozzles, steam traps, etc.) to prevent debris from entering equipment and pipe fittings to damage parts or block pipe fittings and affect normal production operations, thereby stabilizing the process and ensuring safe production. 1.0.2 Responsibilities of pipeline filter selection for process system professional engineering design 1.0.2.1 Select filters of appropriate type and material according to process requirements. 1.0.2.2 Indicate them with specified graphic symbols and abbreviations on the PI diagram, and number and mark them. 1.0.2.3 Complete the engineering design of the filter system (such as drain, vent, bypass, insulation, switching and valve, etc.). 1.0.2.4 Calculate or estimate the pressure loss of the filter system. Prepare filter data sheets and lists, and provide relevant professional engineering design conditions and ordering. 1.0.2.5
2.0.1 Classification by purpose
2.0.1.1 Permanent filter
2 Classification of pipeline filters
(1) Permanent filters are put into normal operation together with the equipment they protect. (2) Requirements for process system professional engineering design a.
The effective area of the mesh permanent filter screen shall not be less than 3 times the cross-sectional area of the operating pipeline. b. The material of the permanent filter body should be equivalent to the material of the pipeline for the same purpose. c.
The specific location of the permanent filter should be indicated on the PI diagram and the special pipe fitting number should be noted. (3) Structural form
Permanent filters can be divided into mesh type, wire gap type, sintered type, magnetic filtration type, etc. according to the structural form. 2.0.1.2 Temporary filter
(1) Temporary filters are only used during the start-up trial operation or when starting up after a long period of parking. They can be removed after the initial operation is completed.
(2) Requirements for professional engineering design of process systems a.
The effective area of the temporary filter screen shall not be less than 2 times the cross-sectional area of the operating pipeline. Temporary filter materials are generally made of carbon steel. If there are strict requirements for the material, special materials can be considered. If the project requires, the specific location of the temporary filter can be indicated on the PI diagram and the abbreviation TS (TEMPORARYSTRAINER) can be noted, and the special pipe fitting number can be marked. (3) Structural form
Temporary filters can be divided into flat type, basket type, T type, Y type, etc. according to their structure. Flat (porous) type is usually used on the suction pipe of centrifugal pumps. Basket type, T type, and Y type are usually used on the suction pipe of reciprocating compressors or liquids with high viscosity such as oil.
The filter mesh used in temporary filters generally uses a filter mesh with 100 holes/cm. 2.0.2 Classification by structure
2.0.2.1 Mesh filter
(1) Mesh filters are widely used in chemical plants and can be used as temporary filters or permanent filters before centrifugal pumps, gear pumps, screw pumps, steam reciprocating pumps, and industrial furnace fuel nozzles. The number of mesh holes used before the pump is generally 144 to 256 holes/cm, which is determined according to the requirements of the pump and nozzle product information. The maximum number of mesh holes can reach 400 holes/cm.
The mesh filter can be divided into SY type, ST type, SC type, SD type and other types. Its shell can be cast iron, 560
carbon steel, low alloy steel, stainless steel or other materials. The filter screen can be divided into copper wire mesh or stainless steel wire mesh. In special cases, the material can be agreed with the manufacturer.
When selecting, refer to the industry standard "Chemical Pipeline Filter" (HGJ532-91). (2) The structural parameters of stainless steel wire mesh are shown in Table 2.0.2-1. Stainless steel wire mesh structural parameters
Mesh number/inch
Interceptable particle size
The wire mesh in the table is a square woven mesh, and the mesh refers to the number of holes (mesh) per inch of length. (3) Approximate pressure drop of mesh pipe filter Table 2. 0.2-1
Opening area percentage
The relationship between nominal diameter (DN) and equivalent straight pipe length (L) is shown in Table 2.0.2-2. Approximate pressure drop of mesh pipe filter DN
Table 2.0.2-2 Notes:
① The data in the table are only for mesh pipe filters. ② When using a 20 mesh/inch filter, take the minimum value. When using a 100 mesh/inch filter, take the maximum value. ④ The unit of L value is m, and the unit of pipe diameter (DN) is mm. 2.0.2.2 Linear gap filter
75~105
Table 2.0.2-2
75~108
The main feature of the linear gap filter is that the filter can remove mechanical impurities during filtering. It is particularly suitable for occasions that require uninterrupted fine filtering of oil products, without the need for additional equipment filters. The structure of the filter is relatively complex and the manufacturing precision requirements are high.
Line gap filters are generally used to filter particulate impurities in hydraulic oil systems and fuel systems. They are mostly used as filters for pump suction ports, oil return lines, and fuel in front of furnaces. At present, there are two types of domestic products: general ones and ones that can send signals when the pressure difference exceeds the allowable value.
2.0.2.3 Sintered filter
This type of filter is made of metal powder (stainless steel, pure nickel, pure iron) sintered into porous materials as filter elements. It is currently mainly used for filtering thermal oil. It can filter out a small amount of polymers and coke (particles) generated during the heat transfer process of thermal oil but cannot be filtered out by general mesh filters, so as to reduce the thermal resistance of thermal oil during heat conduction and improve the heat transfer effect. This type of filter can also be used for filtering transformer oils of various brands and filtering, purifying, and separating gases and liquids. The technical performance is shown in Table 2.0.2-3. Main technical performance table of sintered filter
Using pressure
MPa (table)bzxz.net
2.0.2.4 Magnetic filter
Using temperature
Table 2.0.2-3
Allowable pressure difference
This type of filter is made of a combination of permanent magnetic materials and anti-ferromagnetic materials with high magnetic field strength. Its outer cover is a stainless steel casing. Features: strong adsorption and online cleaning. It is suitable for purifying various oils in hydraulic oil tanks, lubricating oil tanks, and gear oil tanks, and can filter out ferromagnetic particles below 5um. At the same time, it can adsorb various large-particle ferromagnetic harmful particles mixed in the oil tank.
2.0.2.5 Paper and chemical fiber filters
Paper and chemical fiber filters have high precision and can be used in pressure pipelines and return oil pipelines. Some series of return oil filters are also equipped with bypass valves, check valves, liquid flow diffusers, dirt cups and other devices, and are equipped with permanent magnets to filter out ferrous particles.
2.0.2.6 For the models and characteristics of line gap filters, sintered filters, magnetic filtration filters, paper and chemical fiber filters, please refer to the relevant information of the manufacturer.
3 Precautions for installation of pipeline filters
3.0.1 The installation of the filter should be carried out according to the flow direction, recommended installation method and installation requirements shown in the product samples and installation instructions provided by the manufacturer.
3.0.2 A differential pressure gauge or pressure gauge can be set up upstream and downstream of the filter according to the needs of process production to determine the blockage situation, and a backwash cleaning pipeline should be configured according to process needs. 3.0.3 The convenience of installation and removal of permanent and temporary filters should be considered when piping. 3.0.4 Pipeline filter design requirements for pipelines Pipes equipped with filters can be divided into intermittent operation and continuous operation during operation. 3.0.4.1 During intermittent operation, shut-off valves shall be installed before and after the filter to facilitate cleaning of the filter. 3.0.4.2 During continuous operation, two sets of filters in parallel shall be installed for permanent filters, and shut-off valves shall be installed before and after the filters respectively (except for line gap filters). 563
Pipeline filter data sheet and summary list 4.0.1 Pipeline filter data sheet
The pipeline filter data sheet adopts the "Special Pipe Fittings Data Sheet (I)" specified in the industry standard "Provisions for the Contents of Professional Submissions of Process Systems" (HG20558.2-93). See Table 4.0.1 for examples. 4.0.2 Pipeline filter summary list
The pipeline filter summary list adopts the industry standard "Provisions for the Contents of Professional Submissions of Process Systems" (HG20558.2-93) specified in the "Summary of Special Pipe Fittings" 564
Workshop or section (area)
Position number or label number
Installation location
Purpose and use conditions
Media name
Molecular weight
Special pipe fittings data sheet (-)
T-type filter
SP03-0509, SP03-0510
Project number
Inlet pipe PPW-5019-200-×××
Filter a small amount of solid impurities in water
98.5m2/h,
Oil-containing sewage
Approximate water
Viscosity at low temperature is similar to water
Maximum: 128m*/h
Expansion coefficient is similar to water
Maximum working pressure (accident pressure) 95kPaMaximum working temperature (accident temperature)
Pressure at which the pump is shut down
Manufacturing
End connection
Shell:
(Product) Drawing No.: ××-××--1Pressure level, PN1.6MPaFlange connection: HGJ57-91Pressure level: PN1.6MPaLoose flange is CS
Filter: Stainless steel (18-8) wire
Note: Filter specification is ×× mesh/inch
Welding ring is S.S316L
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