JB/T 7376-1994 Technical requirements for pneumatic air pressure reducing valves
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Pneumatic Air Pressure Reducing Valve
1 Subject Content and Scope of Application
JB/T 7376-94
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging and storage of air pressure reducing valves. This standard is applicable to air pressure reducing valves that keep the compressed air pressure basically constant in a closed circuit. Reference Standards
GB2346 Hydraulic and Pneumatic Systems and Components
Newton Nominal Pressure Series
JB1＇6378 Technical Conditions for Pneumatic Directional Control Valves
3 Terms
3.1 Air Pressure Reducing Valve
The air pressure reducing valve is a pneumatic component used to keep the compressed air pressure in a closed circuit basically constant when the working pressure and flow rate change.
3.2 Overflow
Overflow is the unloading of the air pressure reducing valve with an overflow mechanism when the outlet pressure exceeds a given value. 4 Specifications
Specifications are classified by diameter and meet the requirements of Table 1.
Nominal diameter d.mm
Metric, mm
Connecting thread
British.in
5 Technical requirements
5.1 Working conditions
5.1.1 Working medium
Compressed air that has been filtered and dehydrated.
5.1.2 Medium temperature and ambient temperature
The medium temperature and ambient temperature are both 5~~60℃. 5.1.3 Nominal pressure
(G3/8\
The nominal pressure of air pressure reducing valve is selected as 0.63, 1.00, 1.60MPa. 5.2 Performance requirements
5.2.1 Sealing
5.2.1.1 Internal leakage
Approved by the Ministry of Machinery Industry of the People's Republic of China on July 26, 1994 456
M27×2
1995-07 -01 Implementation
JB/T7376—94
Air pressure reducing valve under nominal pressure, when the valve is in the closed state, there should be no leakage at the outlet 5.2.1.2 External leakage
Air pressure reducing valve input nominal pressure, there should be no leakage at the locking cover, diaphragm connection, pressure gauge connection, screw plug, when the top of the valve core rod is hard seal, the overflow at the overflow port is not more than 1cim\/min when the pressure is stable. Valve core rod top When the end is a soft seal, there should be no leakage in the overflow recess. 5.2.2 Pressure resistance
The air pressure reducing valve inputs 1.5 times the nominal pressure, and any parts (components) should be free of damage and water deformation. 5.2.3 The outlet of the air pressure reducing valve is connected to a constant throttle hole, and the relationship curve between the outlet pressure after adjustment and the change of the inlet pressure is shown in Figure 1. When the inlet pressure is adjusted to the nominal pressure, the change value of the outlet pressure is not more than 0.05MPa. Outlet pressure P..MPa
Figure 1 Pressure characteristic curve
5.2.4 Flow characteristics
Inlet pressure P, MPawww.bzxz.net
The inlet pressure of the air pressure reducing valve is the nominal pressure, and the relationship curve between its outlet air flow (under standard conditions) and the outlet pressure is shown in Figure 2.
Outlet pressure P, MPa
Air flow, m*41
Figure 2 Flow characteristic curve
JB/T 7376--94
When the outlet pressure drops to 0.05MPa, the maximum flow rate of the product of the corresponding flow level shall not be less than that specified in Table 2. Table 2
Inlet pressure and outlet pressure
Air flow rate (under standard conditions).m/h
Note: The flow parameters of inlet pressure below 1.0MPa are given by the manufacturer. 5.2.5 Outlet pressure (adjustment range)
The adjustment of the outlet pressure of the air pressure reducing hood shall comply with the outlet pressure in Table 3. Table 3
Outlet pressure
5.2.6 Pressure adjustment
0.05~~0.23
0. 05 - 0. 40
0. 05~- 0. 40
0.05- 0.63
0. 05 -- 0. 40
0. 05, .0. 63
0. 05--- 1. 80
The valve pressure of the air pressure reducing valve is the nominal pressure, and its outlet pressure is uniformly adjustable within the allowable range without step phenomenon. 5.2.7 Overflow characteristics
Under the condition of given pressure, the air pressure reducing valve with overflow structure should be able to cause overflow when the downstream pressure exceeds 35% of the specified value, and draw the characteristic curve of the outlet pressure and overflow flow, as shown in Figure 3. Outlet pressure, MPa
Overflow flow (standard state), dmm
Figure 3 Overflow characteristic curve
5.2.8 Appearance quality
The color of the coating on the outer surface of the air pressure reducing valve should be uniform and smooth, without defects such as scars, scratches and dirt. The label should be fixed and there should be no falling corners. The fasteners should not be loose.
5.2.9 Durability
The durability of air pressure reducing valves shall still comply with the provisions of 5.2.1, 5.2.5 and 5.2.6 when meeting the values specified in Table 4. Table 4
Nominal diameter dmn
Durability.
6 Test method
6.1 Test conditions
6.1.1 Test medium
JB/T 7376- 94
Compression chamber treated by an air filter with a filtration degree of not less than 75um and a water separation efficiency of not less than 80%: 6.1.2 Ambient temperature
Ambient temperature 560C
6.1.3 Relative humidity
Relative humidity not more than 90.
6.1.4 Test pressure
Test pressure shall be as specified in Table 5
Nominal pressure (input)
Pressure resistance
Pressure characteristics
Test items
Flow characteristics
Pressure regulation
Overflow characteristics
Permanence
Test pressure (output)
Allowable fluctuation value of standard pressure
6.1.5 Accuracy of instruments and meters
(1) Internal leakage is
1.5 times of nominal pressure
(2) External leakage is the maximum output pressure
as specified in Table 3
(), t3
Calculate the square as specified in Table 3
1, st:
The accuracy of the pressure gauge for measurement is specified as not less than 0.4 level in the type test, not less than +2.5 level in the factory test, and the upper limit of the measurement range shall not be greater than 2 times the test value: the flow meter shall not be less than +2.5 level: the thermometer (table) is the ordinary level. 6.2 Performance test
6.2.1 Sealing test
6.2.1.1 Internal leakage test
The test pressure of the air pressure reducing valve shall be as specified in Table 5, and the valve shall be closed. Apply soapy water at the outlet and observe for 10$6.2.1.2 External leakage test
The test pressure of the air pressure reducing valve shall be as specified in Table 5, the outlet pressure shall be adjusted to the maximum, the outlet pipeline shall be closed, and soapy water shall be applied at the locking cover, diaphragm connection, pressure gauge connection, and flow connection to check for 108. When the top of the valve stem is a hard seal, connect a flow meter (or use the flow collection method) to the overflow port to measure 6.2.2 Pressure resistance test
The test pressure of the air splash valve is as specified in Table 5. The output pressure is adjusted to the maximum, the output is closed, and the pressure is maintained for 1 minute. Check: 6.2.3 Pressure characteristic test
6.2.3.1 The test path is as shown in Figure 4. The pressure-taking hole is as shown in Figure 5, and the constant throttle hole structure is as specified in Figure 6 and Table 6 16
Nominal diameter d
JB/T 7376
Air source; 2Stop valve; 3Air pressure reducing valve, 4.6Pressure gauge; ·--Valve under test; ?Constant throttle hole Figure 4 Schematic diagram of pressure characteristic test circuit
1The hole shall not have protrusions and burrs
Figure 5 Structure diagram of pressure taking hole
Constant throttle hole diameter shear
Constant throttle hole structure
6.2.3.2The input pressure of the air pressure reducing valve is 0.05MPa higher than the outlet pressure specified in Table 5. The outlet pressure is adjusted as specified in Table 5. 6.2.3.3 Adjust the inlet pressure of the valve under test and measure the outlet pressure for ··times every time the outlet pressure increases by 0.05MPa until the inlet E force is adjusted to the nominal positive force. Draw the measured outlet pressure value into a curve and calculate the change in pressure. 6.2.4 Flow characteristics
Test circuit according to Figure 7
1- Air source 2- Shutoff valve; 3- Air pressure reducing valve: 4.6 Pressure gauge, 5- Tested air pressure reducing valve; 7- Throttle valve; Flow meter Figure? Flow characteristics test circuit principle diagram
The test pressure of the air pressure reducing valve is as specified in Table 5. During the test, the inlet pressure remains unchanged. 6.2.4.3 Slowly adjust the throttle valve opening, and measure the pressure and flow each time until the outlet pressure drops to .05MPc. 6.2.4.4 Draw the flow and pressure curve according to the measured values, and measure the pressure drop to (.05MPa flow value, 460
6.2.5 outlet pressure test
6.2.5.1 Test circuit according to Figure 7.
JB/T 7376--94
6.2.5.2 After the tested valve is closed, the test pressure shall be in accordance with the provisions of Table 5, and the range of its outlet pressure shall be adjusted. 6.2.6 Pressure adjustment test
The test pressure of the air pressure reducing valve shall be in accordance with the provisions of Table 5, and the test shall be carried out by continuous adjustment within the range of the outlet pressure. 6.2.7 Overflow characteristic test
6.2.7.1 The test circuit shall be connected according to Figure 8,
1--air source, 2.4--air pressure reducing valve: 3, 7, 8 pressure gauge: 5 tested air pressure reducing valve; 6-flow meter; 9--stop valve; 10 measuring cup Figure 8 Schematic diagram of overflow characteristic test circuit
6.2.7.2 The test pressure of the tested valve 5 shall be in accordance with the provisions of Table 5. 6.2.7.3 Adjust the outlet pressure of the air pressure reducing valve 4 from small to large. When the outlet pressure of the tested valve 5 begins to overflow, record the outlet pressure and overflow flow (if the top of the valve core stem of the tested valve is a hard seal, the overflow flow in the equilibrium state is used as the benchmark and calculated from the increased flow); then measure the overflow flow once for every increase of 0.05MPa outlet pressure, and measure 5 to 10 times. Draw a characteristic curve based on the measurement results. 6.2.8 Durability test
The test circuit is as shown in Figure 9.
1--Air source; 2--Stop valve: 3--Air pressure reducing valve; 4, 7--Pressure gauge: 5.9--One-position two-way valve (can be controlled by machine, electricity or gas); G--Tested air pressure reducing valve; 8-Counter Figure 9 Schematic diagram of durability test circuit
6.2.8.2 The test pressure of the tested valve is as specified in Table 5, JB/T 7376--94
6.2.8.3 Make the two-way valves 5 and 9 switch at a frequency of 1H%, and the two valves switch in the opposite direction synchronously, continuously or intermittently. After completing the number of actions, conduct inspection.
6.3 Appearance quality inspection
Appearance quality is inspected by self-testing method
7 Inspection rules
7.1 Delivery inspection
7.1.1 The air pressure reducing valve can be shipped only after it has passed the inspection of the inspection department, and a certificate of conformity shall be attached. 7.1.2 The mandatory inspection items for delivery are 5.2.1, 5.2.5, 5.2.6 and 5.2.8. 7.1.3 Sampling inspection items for delivery are 5.2.2
7.1.4 The number of sampling inspections is 2% of each batch (natural batch), but shall not be less than 3 sets. 7.1.5 Judgment rules
According to Article 6.1.4 of JB/T6378
7.2 Type inspection
When the following situations occur, the product should be subject to type inspection: when a new product is trial-produced or an old product is transferred to another factory for production; after formal production, if there are major changes in structure, materials, and processes that may affect product performance; during normal production, regular inspections should be carried out, not less than once every three years: when the product is resumed after one year of suspension of production; d.
When the factory inspection results are significantly different from the last type inspection; when the national quality supervision agency proposes the requirement for type inspection, the number of pneumatic components for type inspection is stipulated to be 3 units (pieces). One unit (piece) is subject to full-item test, and the rest are subject to performance test. If there are unqualified items in the test, the tested piece should be double inspected. If there are still unqualified ones, the pneumatic component type inspection is unqualified. Marking, packaging, storage
8.1 Marking
The outer surface of the air pressure reducing valve should be marked with:
8. 1. 1′
Product name, model, specification:
Nominal pressure:
Outlet pressure (adjustment range);
Flow direction;
Thread mark of the pipe;
Manufacturer name;
Manufacturer date.
8.2 Packaging
8.2.1 Inner packaging
Material such as paper box, polyethylene blown film for packaging, polyethylene air cushion film, polyurethane foam plastic, etc. should be used. Packed in plastic bags: each component (set) is packed into one bag, and the bag mouth is folded. b.
C. Packed in paper boxes: each 1, 2 or 5 bags are packed into a box. 8.2.2 Outer packaging
The outer packaging of the components should be made of cardboard boxes, calcium plastic corrugated boxes or nail board boxes. The outer packaging with special requirements shall be double-delimited. 462
JB/T7376-94
Each air pressure reducing valve should be stored in a warehouse with an air temperature of 5~10C and a relative humidity of no more than 80%. The air in the warehouse should not contain corrosive and harmful impurities.
Additional instructions:
This standard was proposed and coordinated by the Wuxi Pneumatic Technology Research Institute of the Ministry of Machinery Industry. This standard was drafted by Shanghai Pneumatic Complete Set Company and Wuxi Pneumatic Technology Research Institute. The main drafters of this standard are Zou Zongfa and Zhang Jiansong16532 Outer packaging
The outer packaging of the components should be made of cardboard boxes, calcium plastic corrugated boxes or nail board boxes. The outer packaging with special requirements must be double-delimited. 462
JB/T7376-94
Each air pressure reducing valve should be stored in a warehouse with an air temperature of 5~10C and a relative humidity of no more than 80%. The air in the warehouse should not contain corrosive and harmful impurities.
Additional instructions:
This standard was proposed and coordinated by the Wuxi Pneumatic Technology Research Institute of the Ministry of Machinery Industry. This standard was drafted by Shanghai Pneumatic Complete Set Company and Wuxi Pneumatic Technology Research Institute. The main drafters of this standard are Zou Zongfa and Zhang Jiansong16532 Outer packaging
The outer packaging of the components should be made of cardboard boxes, calcium plastic corrugated boxes or nail board boxes. The outer packaging with special requirements must be double-delimited. 462
JB/T7376-94
Each air pressure reducing valve should be stored in a warehouse with an air temperature of 5~10C and a relative humidity of no more than 80%. The air in the warehouse should not contain corrosive and harmful impurities.
Additional instructions:
This standard was proposed and coordinated by the Wuxi Pneumatic Technology Research Institute of the Ministry of Machinery Industry. This standard was drafted by Shanghai Pneumatic Complete Set Company and Wuxi Pneumatic Technology Research Institute. The main drafters of this standard are Zou Zongfa and Zhang Jiansong1653
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