This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage, etc. of speed-adjustable pneumatic pipe joints. This standard is applicable to speed-adjustable pneumatic pipe joints with compressed air as the working medium. JB/T 7057-1993 Technical conditions for speed-adjustable pneumatic pipe joints JB/T7057-1993 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7057-1993
Speed-adjustable pneumatic pipe joints
Published on September 23, 1993
Technical conditions
Implementation on July 1, 1994
Ministry of Machinery Industry of the People's Republic of China
Mechanical Industry Standard of the People's Republic of China
Speed-adjustable pneumatic pipe joints
Subject content and scope of application
Technical conditions
JB/T7057-1993
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage, etc. of speed-adjustable pneumatic pipe joints. This standard applies to speed-adjustable pneumatic pipe joints with compressed air as the working medium. Cited standards
GB2351
GB7932
GB7937
JB/T7056
JB/JQ207005
JB/JQ207017
Terms, symbols, 1
Hydraulic and pneumatic systems and components
Nominal inner diameter size series of hoses
General technical conditions for pneumatic systems
Nominal pressure series of hydraulic and pneumatic pipe joints and accessories General technical conditions for pneumatic pipe joints
Technical conditions for pneumatic exhaust throttle valves
Technical conditions for pneumatic component packaging
According to the provisions of Chapter 3 of JB/T7056.
Technical requirements
4.1 Working conditions
According to the provisions of Article 5.1 of JB/T7056.
Performance
Performance should comply with the requirements in Table 1.
Nominal diameter
Effective cross-sectional area
Manufacturing requirements
Throttling characteristics
The curve is flat and submerged, the linearity is good, and there is no sudden change
Pressure resistance
No cracking, deformation
and other damage
Parts processing, assembly,
Appearance quality shall comply with the requirements of JB/T7056.
Test method
Test conditions
Approved by the Ministry of Machinery Industry on 1993-09-23
Leakage
cm/min
≤100
Pulling strength
≥250
≥400
≥600
Repeated assembly and disassembly
When the joint is repeatedly assembled
, there shall be no||tt ||Leakage and other
Abnormal phenomena
1994-07-01
5.1.1 Medium
Name: Compressed air;
Temperature: 20±15℃;
Pressure: All test pressures shall be in accordance with Table 2: JB/T7057-1993
Filtration accuracy: The filter's filtration accuracy is 25~50μm, and the water separation efficiency is not less than 80%.
Nominal pressure
Effective cross-sectional area
Throttling characteristics
Test pressure
Environmental conditions
Slippage
Pressure resistance
Allowable fluctuation value
a.Environmental temperature: 25±5℃;
Relative humidity: not more than 85%.
Testing instruments and meters and their accuracy shall be in accordance with the provisions of Table 3 5. 1.3
Instrument and meter categories
Standard pressure gauge
Standard hygrometer
Flowmeter
Test methods shall be in accordance with the provisions of Table 4.
Test items
Effective cross-sectional area
0.63×1.5
Test method
The principle of the test system is shown in Figure 1:
AccuracywwW.bzxz.Net
Not less than 0.4 level
Error not more than ±0.2℃
Not less than 2.5 level
Make the speed regulating pipe joint under test in the fully open position and pass the specified test pressure. Measure the pressure and flow rate before and after the tested pipe joint, and use the following formula to calculate the effective cross-sectional area S value:
When p:=（1-1.893）p2
Q×273
Where: S——effective cross-sectional area, mm2; Q—volume flow rate, L/s:
Pi——static pressure before the tested pipe joint, MPa: P—static pressure after the tested pipe joint, MPa:—Room temperature, K
1.00×1.5
Test items
Section Flow characteristics
Pressure resistance
Pulling strength
Repeated assembly and disassembly test
Appearance quality
JB/T7057-1993
Continued Table 4
Test method
The principle of the test system is shown in Figure 1:
Make the pipe joint under test in the fully closed position, pass the specified test pressure, adjust the throttle rod,
make it in different opening positions until it is fully open, and measure the effective cross-sectional area S value of each opening at the same time. And make a -S relationship curve (throttling characteristic curve) hS curve with the S value of each measured point
Throttle rod lifting height:
S——effective cross-sectional area
The principle of the test system is shown in Figure 1;
Make the pipe joint under test in the fully open position. Close switch 6 and pass the specified test pressure, maintain the pressure for 1min
Make the tested pipe joint in the fully closed position, and pass the specified test pressure along the air intake direction. Measure the leakage on the exhaust side, repeat 3 times, and take the average value
The principle of the test system is shown in Figure 2:
Install a pipe with a free length of 100mm on the joint. And conduct it on a tensile testing machine. The tensile force should not be less than that specified in Table 2. Stretch at a speed of about 200mm/min
After repeatedly assembling and disassembling the joint and the pipe 5 times, perform the oil leakage performance test according to No. 4, which should meet the requirements of leakage and repeated assembly and disassembly performance in Article 4.2
Use visual inspection and hand feeling method!
It should meet the requirements of Article 4.3
The measurement points shall not be less than 5 points
Inspect for external leakage, cracking, deformation
and other changes
Inspect that the test piece should not be pulled off. No
Inspection rules
JB/T 7057-1993
Figure 1 Schematic diagram of effective cross-sectional area, throttling characteristics and pressure resistance test system 1—gas source: 2, 6—switch: 3, 5—pressure gauge: 4—speed regulating joint: 7—flow meter calibration joint
Pressure question
According to the provisions of JB/T7056.
7 Marking, packaging, transportation and storage
According to the provisions of JB/T7056.
Additional instructions:
This standard is proposed and managed by Wuxi Pneumatic Technology Research Institute. Piping
This standard was drafted by Fuxin General Pneumatic Accessories Factory, Liaoning Province. The main drafters of this standard are Wang Jinchun and Li Yingwu. Wrinkle test joint
Closed end
JB/T7057-1993
People's Republic of China
Mechanical industry standard
Technical conditions for speed-adjustable pneumatic pipe joints
JB/T 70571993
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
Format: 880×1230
Printing Sheet: 1/2
Word Count: 8,000
First Edition: May 1994
First Printing: May 1994
Print Quantity: 1-500
Price: RMB 3.00
Mechanical Industry Standards Service Network: http://www.JB.ac.cn661
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