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Mechanical Industry Standard of the People's Republic of China
JB/T7255-94
Water Ring Vacuum Pump and Water Ring Compressor
Published on July 18, 1994
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1995
Mechanical Industry Standard of the People's Republic of China
Water Ring Vacuum Pump and Water Ring Compressor
Subject Content and Scope of Application
JB/T7255-94
This standard specifies the type and basic parameters, technical requirements, test methods, inspection rules, product set and use guarantee, marking, packaging, transportation and storage of water ring vacuum pumps and water ring compressors (collectively referred to as water ring pumps when no distinction is made). This standard applies to water ring pumps with a suction or delivery temperature of 10~40℃, a working water temperature of 0~35℃, and no solid particles or corrosive gases.
For water ring pumps that pump or pressurize corrosive gases and use other non-aqueous liquids as working liquid rings, this can be used as a reference. Reference standards
GB2828
GB4216
GB4662
GB4879
GB5661
GB6391
GB9239
GB10889
GB10890
GB/T13306
GF/ T13384
GB/T13929
JB4127
JB/T4297
JB/T6880.1
JB/T6880.2
3 Terminology
3.1 Gas volume
Batch inspection counting sampling procedure and sampling table (applicable to continuous batch inspection) Gray cast iron pipe flange size| |tt||Rated static load of rolling bearings
Rust-proof packaging
Axial suction centrifugal pumps
Cavity dimensions for mechanical seals and soft packingsCalculation methods for rated dynamic loads and rated life of rolling bearingsBalance quality of rigid rotorsDetermination of allowable imbalanceMeasurement and evaluation methods for vibration of pumps
Noise measurement and evaluation methods
General technical conditions for packaging of electromechanical products
Test methods for water ring vacuum systems and water ring compressorsTechnical conditions for mechanical seals
Technical conditions for coating of pump products
Gray iron castings for pumps
Steel castings for pumps
The gas volume of a water ring vacuum pump refers to the volume of gas under suction in the pump inlet per unit time when the inlet is at a given vacuum degree and the outlet is at an atmospheric pressure of 1013.25hPa, m\/min. The gas volume of the water ring compressor refers to the volume of gas passing through the compressor inlet per unit time when the outlet is at the rated discharge pressure and the inlet is at the atmospheric pressure of 1013.25hPa, m*/min. 3.2 Maximum gas volume
The maximum gas volume of the water ring vacuum pump (or water ring compressor) refers to the maximum gas volume on the gas volume curve. m\/min. 3.3 Vacuum degree (or pressure)
Approved by the Ministry of Machinery Industry on July 18, 1994
Implementation on July 1, 1995
JB/T7255-94
The vacuum degree of the water ring vacuum pump refers to the rarefaction of the gas at the inlet under the vacuum state, expressed as absolute pressure, hPa. 3.4 Ultimate vacuum degree (or ultimate pressure) The ultimate vacuum degree of the water ring vacuum pump refers to the vacuum degree when the inlet suction gas volume is zero, hPa. 3.5 Discharge pressure
The discharge pressure of a water ring compressor refers to the difference between the absolute pressure at the outlet and the atmospheric pressure, MPa. 3.6 Working pressure range
The working pressure range of a water ring compressor refers to the discharge pressure range allowed for use. 4
Types and basic parameters
4.1 Types
Water ring vacuum pumps and water ring compressors are divided into the following types: a.
Single-stage water ring vacuum pump (including water ring compressor); two-stage water ring vacuum pump.
The above types can be made into single-acting axial suction and exhaust or radial suction and exhaust and double-acting axial suction and exhaust or radial suction and exhaust. The water ring vacuum ticket can also be made into a structural type used in combination with an atmospheric ejector. 4.2 Models
4.2.1 Indication of water ring vacuum pumps
Number of atmospheric ejectors, 1 for one stage, 2 for two stages. Equipped with atmospheric ejectors
Maximum gas volume, m/min
Pumps with the same maximum gas volume but different ultimate vacuum degrees. A represents higher and B represents lower
Number of water ring vacuum pumps (including vacuum pumps that can be used as compressors)Number of water ring vacuum pumps, single stage is not indicated, 2 represents two stages.Marking example ：
Single-stage water ring vacuum pump with maximum gas volume of 6m/min (including water ring vacuum pump that can also be used for compression): SK-6
Maximum gas volume is 30m/min. When the maximum gas volume of the two pumps is the same, but the ultimate vacuum degree is different, the single-stage water ring vacuum pump with high ultimate vacuum degree is:
SKA-30
Two-stage water ring vacuum pump with maximum gas volume of 6m*/min: 2SK-6
Maximum gas volume is 6m/ min, single-stage water ring vacuum pump with one-stage atmospheric ejector: SK-6P1
Maximum gas volume is 6m*/min, two-stage water ring vacuum pump with one-stage atmospheric ejector: 2SK-6P1
4.2.2 Indication method of water ring compressor
Maximum gas volume, m\/min
The maximum gas volume is the same, but the working pressure is different. A represents higher and B represents lower
Water ring compressor
Marking Example:
Water ring compressor with maximum gas volume of 42m\/min: SY-42
JB/T725594
Maximum gas volume is 30m/min. When the maximum gas volume of the two compressors is the same, but the working pressure is different, the water ring compressor with higher pressure:
SYA-30
Basic parameters
The basic parameters of the water ring vacuum pump and water ring compressor should meet the requirements of Table 1, Table 2 and Table 3 respectively. The water ring vacuum pump and water ring compressor should be used under the following conditions: the working medium of the pump is air, the working liquid ring of the ticket is water; atmospheric pressure 1013.25hPa,
the temperature of the inhaled gas is 20℃, the relative humidity is 70%: the working water temperature is 15℃;
specified speed, r/min.
The performance tolerances in Table 1, Table 2 and Table 3 are in accordance with the provisions of GB/T13929. Table 1 Single-stage water ring vacuum pump
Maximum gas volume
m*/min
SKA-20
SKB-20
SKA-30
SKB-30
SK-120
SK-180
SK-250
Note: 1) The speed is the recommended speed, the same below. 2) The diameter is the recommended diameter, the same below.
Ultimate vacuum degree
With one-stage large
gas ejector
Ultimate vacuum degree
With two-stage large
gas ejector
Ultimate vacuum degree
As compressor
Working
Pressure range
Speed"
Suction and discharge
Diameter*
2SK-12
2 SK-20
2SK-30
SYA-12
SYB-12
SYA-20
SYB-20
SYA-30
SYB-30
SY-120
5Technical requirements
Maximum gas volume
m=/min
Maximum gas volume
JB /T7255-94
Two-stage water ring vacuum compressor
Ultimate vacuum
Gas volume at working pressure
m*/min
Ultimate vacuum with first-stage atmospheric ejector
Single-stage water ring compressor
Working pressure
Gas volume at working pressure
m*/min
Working pressure
Suction and discharge port diameter\
Suction and discharge
Outlet diameter"
5.1 Performance
The manufacturer shall provide a complete characteristic curve according to the provisions of Article 4.3.2 of this standard. The single-stage water ring vacuum pump shall include the gas volume under the vacuum degree of 400hPa, and the two-stage water ring vacuum pump shall include the gas volume under the vacuum degree of 80hPa (the above gas volume points are usually used as the measurement points for type inspection and factory test).
5.2 Installation
If the ticket is required to be installed outdoors, the buyer shall jointly agree with the seller on the environmental conditions for outdoor installation. 5.3 Prime mover
The prime mover power of the pump shall generally be selected at a rate not less than 1.1 times the maximum shaft power within the specified range of use of the pump. When it is determined that the shaft power of the pump4
JB/T7255-94
will not exceed the prime mover power under any circumstances, no or less additional margin may be reserved. 5.4 Critical speed
Under working conditions, the actual first lateral critical speed of the rotor shall exceed the operating speed by at least 10%. 5.5 Balance and vibration
5.51 Balance
The impeller shall be subjected to static or dynamic balance tests. The static and dynamic balance degrees shall not be lower than the G6.3 level specified in GB9239. 5.5.2 Vibration
The vibration intensity of the water ring pump shall not exceed the specified value of Class C in GB10889. When the center height of the pump is greater than 550mm and the speed is less than or equal to 600r/min, the vibration level can be evaluated according to the category of >600~1500r/min.
5.6 Noise
The noise level of the water ring pump shall not exceed the specified value of Class C plus 6dB(A) in GB10890. 5.7 Pressure-bearing parts
5.7.1 Pressure
The selection of the nominal pressure of the inlet and outlet flanges of the water ring vacuum pump shall not be less than 0.25MPa specified in GB4216. The manufacturer shall clearly specify the ultimate pressure (maximum allowable working pressure) of the water ring compressor, which shall not exceed the nominal pressure of the flange. 5.7.2 Wall thickness
Parts subject to fluid pressure shall have sufficient thickness to withstand the maximum permissible working pressure at the working temperature and the test pressure at the ambient temperature during the water pressure test. 5.8 External forces and torques at the inlet and outlet If the buyer requires, the manufacturer shall provide detailed data on the external forces and torques permissible on the pump inlet and outlet pipe connections.
5.9 Pump inlet and outlet flanges
The dimensions of the pump inlet and outlet flanges and the dimensions of the gray cast iron flanges shall comply with the provisions of GB4216. The screw holes on the pump flange shall be arranged across the center line 5.10 The position, shape and size of the side cover (or suction and exhaust plate) and the distributor suction and exhaust ports shall be correct and shall not have excessive deviations. 5.11 Impeller
The impeller shall be securely fixed on the shaft to prevent axial and circumferential movement (excluding the impeller structure with free clearance sliding on the shaft). 5.12 Running Clearance
When determining the running clearance between stationary and rotating parts, the operating conditions and the properties of the materials used for these parts (such as hardness and abrasion resistance) should be considered. The size of the clearance should prevent mutual contact under working conditions. The selected material combination should minimize the risk of wear and seizure.
When using gray cast iron material, the running clearance of the water ring pump can be selected according to Table 4 and Table 5. Table 4 Matching clearance between the impeller and the side cover (or exhaust plate) for axial suction and exhaust Impeller outer diameter
>180~500
>500~1000
Minimum clearance on one side
Total clearance control range on both sides
0.30~0.40
0.40~0.55
Impeller hole matching with distributor
Basic size mm
>80~120www.bzxz.net
>120~180
>1 80~250
>250~315
>315~400
>400~5.00
>500~630
>630~800
JB/T7255-94
Radial suction and exhaust impeller and distributor matching gap distributor matching
Tolerance zone
Diameter tolerance zone
Shaft and sleeve
The pump shaft should have sufficient shaft diameter to meet the strength and rigidity requirements. The diameter of the parts related to the shaft and sleeve and the seal should comply with the provisions of GB5661. Minimum total clearance
The parts related to the shaft and sleeve and the seal, if mechanical seals are installed, should comply with the provisions of 5.16.3. 5.14 Assembly of the sleeve on the shaft
Gas shall not be allowed to enter the pump from between the sleeve and the shaft. 5.15 Bearings
5.15.1 General
Standard type rolling bearings shall normally be used. 5.15.2 Rolling bearing life
Total clearance variation range
0.25~0.339
0.25~0.353
0.25~0.368
0.30~0.433
0.30~0.446
0.30~0.460
0.40~0.580
0.40~0.605
Rolling bearings should be calculated and selected in accordance with the requirements of GB4662 and GB6391; the "basic rated life (L10)" when operating within the allowable working range should be at least 10000h.
5.15.3 Operating temperature of bearings
The operating temperature of bearings shall not be higher than 35℃ of ambient temperature, and the maximum temperature of bearings shall not be higher than 75℃. 5.15.4 Lubrication
The instruction manual shall contain the type, dosage and usage rate of the lubricant used. 5.15.5 Design of bearing box
Under normal working conditions, the bearing box can prevent the intrusion of impurities and the loss of lubricant. 5.16 Shaft seal
5.16.1 General
The shaft seal of the pump is allowed to use soft packing or mechanical seal. Unless otherwise required by the working conditions, the size of the seal cavity shall comply with the provisions of GB5661. 5.16.2 Stuffing box
The stuffing box shall provide sufficient space for replacing the packing. The packing gland shall be able to withstand the force required to compress the packing. 5.16.3 Mechanical seal
The mechanical seal shall be able to withstand the given working conditions. The selected sealing element material should be able to meet the requirements of working conditions such as corrosion, wear, temperature and mechanical stress. The hydraulic test pressure of the mechanical seal should not exceed the ultimate sealing pressure. 6
JB/T 7255-94
The installation requirements for mechanical seals should comply with the provisions of Chapter 5 of JB4127. 5.17 Coupling
The connection between the pump and the prime mover should adopt a flexible coupling, and the coupling should be effectively fixed to prevent axial and circumferential movement. If the various parts of the coupling are assembled together for balancing, permanent and significant marks should be used to indicate their correct assembly position. An effective protective cover should be provided, and the design of the protective cover should comply with the relevant national safety regulations. 5.18 Base
5.18.1 General
The base without grouting should have sufficient rigidity to meet the requirements of direct installation on the foundation. The base that needs grouting should be designed to ensure correct grouting (such as preventing air accumulation, etc.). 5.18.2 Assembly of pump and prime mover on the base When assembling the pump and prime mover on the base, the difference between the prime mover and pump axis in the vertical direction can be adjusted by gaskets to meet the requirement that the two axis center lines are consistent.
If the prime mover is not installed by the manufacturer and there is no other provision, the base should not be drilled with a mounting hole for the prime mover. 5.19 Materials
Material selection Unless the buyer has other requirements for materials, it should usually be determined by the supplier based on the working medium and intended use of the pump. 5.20 Casting quality
For gray iron castings for pumps, the casting quality should comply with the provisions of JB/T6880.1; for steel castings for pumps, the casting quality should comply with the provisions of JB/T6880.2. 6 Test methods
6.1 Chemical analysis and mechanical property test of materials The chemical analysis and mechanical property test methods of materials should comply with the provisions of relevant standards. 6.2 Water pressure test
6.2.1 The shell that bears fluid pressure should be subjected to water pressure test. The test pressure of vacuum pump is 0.3MPa. The test pressure of compressor should not be less than 2 times of the working pressure, but the minimum test pressure should not be less than 0.3MPa. 6.2.2 The water pressure test is carried out with clean water at ambient temperature. The duration of the test pressure should not be less than 5min, and there should be no water seepage or leakage.
6.3 Performance test
The performance test method of water ring pump shall be in accordance with the provisions of GB/T13929. 6.4 Vibration measurement
The vibration measurement method of water ring pump shall be in accordance with the provisions of GB-10889. 6.5 Noise measurement
The noise measurement method of water ring pump shall be in accordance with the provisions of GB10890. 7
Inspection rules
The inspection of water ring pump is divided into type inspection and factory inspection. 7.1 Type inspection
Type inspection should generally be carried out when any of the following conditions occur: 7.1.12
Trial production and identification of new products or old products transferred to the factory for production; after formal production, if there are major changes in structure, materials, and processes that may affect product performance; periodic inspection of mass production;
When the product is resumed after a long period of suspension; when the factory inspection results are significantly different from the last type inspection. JB/T 725594
7.1.2 The number of items and measurement points for type inspection shall comply with Article 3.8 of GB/T13929, and the performance tolerance shall comply with Article 8.1 of GB/T13929.
7.1.3 The number of units to be inspected shall not be less than 2.
7.2 Factory inspection
7.2.1 Products produced in mass production shall be subject to factory inspection. 7.2.2 The items and number of test points for factory inspection shall comply with Article 3.8 of GB/T13929, and the performance tolerance shall comply with Article 8.1 of GB/T13929.
7.2.3 The number of inspection units and sampling rules shall comply with the provisions of GB2828. The sampling method may use single or double sampling, and the inspection level 1 and qualified quality level AQL 4 shall be adopted.
8 Product set and use guarantee
Product set
Users can order all or part of the following set range according to their needs, and shall indicate it in the order form. The scope of supply includes: a.
Water ring vacuum pump (or water ring compressor);
Base;
Prime mover and transmission part (such as motor, reducer, etc.); gas-water separator;
Ejector with vacuum pump:
Special tools for disassembly and assembly;
Special spare parts and other accessories.
8.2 Under the condition that the buyer complies with the transportation, storage, installation and use rules of the pump, within 18 months from the date of shipment from the manufacturer and the service life does not exceed 12 months, if the product is damaged or cannot work normally due to poor manufacturing quality, the manufacturer shall repair or replace parts or products for the buyer free of charge (but excluding normal wear and tear of wearing parts). 9 Marking, packaging, transportation and storage
9.1 Marking
9.1.1 Each pump shall be nailed with a product label in a conspicuous position, and the size and technical requirements of the label shall comply with the provisions of GB/T13306. The label should be made of materials resistant to environmental corrosion. The label should include the following contents: a.
Manufacturer name and trademark;
Pump model and name;
Main parameters of the pump:
Maximum gas volume
Ultimate vacuum degree (for vacuum pump)
Working pressure range (for compressor)
Equipped power
Pump mass
Factory number and manufacturing date of the pump.
m\/min
9.1.2 The rotation direction of the pump should be indicated by a red head in an appropriate and obvious position (cast or nailed on a separate label). 9.2 Packaging and transportation
9.2.1 Preparations before packaging:
If there is water inside the pump, it should be removed;
If the buyer does not make special requirements, the pump painting should be in accordance with the provisions of JB/T4297; c
Requirements;
JB/T7255-94
The anti-rust treatment of the pump should comply with the relevant provisions of GB4879. If the buyer does not make any requirements. The anti-rust validity period should comply with D-grade bearings. If it is dry oil lubrication, an appropriate amount of grease should be filled; The suction and discharge ports of the pump and the various pipe openings on the pump leading to the outside should be blocked, and the blocking parts should be resistant to wind and rain erosion and able to withstand accidental damage;
f. The technical documents accompanying each unit when it leaves the factory, such as: product certificate, packing list, instruction manual, etc., should be sealed in a waterproof bag. 9.2.2 Packaging
The packaging of the pump shall comply with the provisions of GB/T13384. Tickets, spare parts and accessories shall be reliably fixed during packaging to prevent collision. 9.2.3 Transportation
During transportation, protective measures shall be taken to prevent damage to the product and packaging box caused by vibration or collision. 9.3 Storage
The pump shall be protected from rust and damage during storage. The pump shall be inspected on time according to the anti-rust period and re-treated for anti-rust. JB/T7255-94
Appendix A
Data Sheet
(Reference)
A1 If data sheets are required, the data of water ring vacuum pumps and water ring compressors can be applied to: buyer's inquiry, ordering and contract processing;
supplier's bidding and manufacturing.
The data sheet can be enlarged or divided into several pages, but the line number should comply with the data sheet of this standard. Instructions for filling out the data sheet are as follows: A2
Use the symbol "×" in the appropriate column to indicate the required information; The rows marked with "^" must be filled in by the buyer when inquiring: Blank columns can be used to indicate required information, and can also be used to indicate symbols for supplementing or modifying information; To facilitate the transmission of information in designated rows and columns, the following table can be used: Three-column row
Example:
Column 1
Row 26/2
Two-column row
Example:
One-column row
Row 51/
Example:
Row 7
A row number
Column 1
Column 2
Column 2
Column 32 Packaging
The packaging of the pump shall comply with the provisions of GB/T13384. Tickets, spare parts and accessories shall be reliably fixed during packaging to prevent collision. 9.2.3 Transportation
During transportation, protective measures shall be taken to prevent damage to the product and packaging box caused by vibration or collision. 9.3 Storage
The pump shall be protected from rust and damage during storage. The pump shall be inspected on time according to the anti-rust period and re-treated for anti-rust. JB/T7255-94
Appendix A
Data Sheet
(Reference)
A1 If data sheets are required, the data of water ring vacuum pumps and water ring compressors can be applied to: buyer's inquiry, ordering and contract processing;
supplier's bidding and manufacturing.
The data sheet can be enlarged or divided into several pages, but the line number should comply with the data sheet of this standard. Instructions for filling out the data sheet are as follows: A2
Use the symbol "×" in the appropriate column to indicate the required information; The rows marked with "^" must be filled in by the buyer when inquiring: Blank columns can be used to indicate required information, and can also be used to indicate symbols for supplementing or modifying information; To facilitate the transmission of information in designated rows and columns, the following table can be used: Three-column row
Example:
Column 1
Row 26/2
Two-column row
Example:
One-column row
Row 51/
Example:
Row 7
A row number
Column 1
Column 2
Column 2
Column 32 Packaging
The packaging of the pump shall comply with the provisions of GB/T13384. Tickets, spare parts and accessories shall be reliably fixed during packaging to prevent collision. 9.2.3 Transportation
During transportation, protective measures shall be taken to prevent damage to the product and packaging box caused by vibration or collision. 9.3 Storage
The pump shall be protected from rust and damage during storage. The pump shall be inspected on time according to the anti-rust period and re-treated for anti-rust. JB/T7255-94
Appendix A
Data Sheet
(Reference)
A1 If data sheets are required, the data of water ring vacuum pumps and water ring compressors can be applied to: buyer's inquiry, ordering and contract processing;
supplier's bidding and manufacturing.
The data sheet can be enlarged or divided into several pages, but the line number should comply with the data sheet of this standard. Instructions for filling out the data sheet are as follows: A2
Use the symbol "×" in the appropriate column to indicate the required information; The rows marked with "^" must be filled in by the buyer when inquiring: Blank columns can be used to indicate required information, and can also be used to indicate symbols for supplementing or modifying information; To facilitate the transmission of information in designated rows and columns, the following table can be used: Three-column row
Example:
Column 1
Row 26/2
Two-column row
Example:
One-column row
Row 51/
Example:
Row 7
A row number
Column 1
Column 2
Column 2
Column 3
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