Created on:2021-05-21 08:59

General specification for hydraulic components

General specification for hydraulic components

(1) Scope. This standard specifies the general technical conditions for hydraulic components. This standard is applicable to hydraulic components for general industrial use with hydraulic fluid or other hydraulic fluid with equivalent performance as working medium.

Note: hydraulic accessories can refer to this standard.

(2) Technical requirements

① The basic parameters and installation connection dimensions of hydraulic components shall comply with the provisions of GB / T 2346, GB / T 2347, GB / T 2348, GB / T 2349, GB / T 2350, GB / T 2353, GB / T 2514, GB / T 2877, GB / T 2878, GB / T 8098, GB / T 8100, GB / T 8101 and GB / T 14036.

② Pressure test shall be conducted for pressure bearing channel of hydraulic components, and the test method shall be in accordance with relevant standards of each component.

③ Shell

a. The shell of the element shall be treated accordingly to eliminate the internal stress. The shell shall be free from process defects affecting the use of components and shall reach the required strength of components.

Note: flaw detection should be carried out for complex castings.

b. The shell surface shall be flat and smooth, and there shall be no process defects affecting the appearance quality of components.

’c. The casting should be cleaned, and there should be no residue in the internal channel and cavity.

④ Components shall be assembled with qualified parts and purchased parts according to relevant product standards or technical documents. Any deformed, damaged and corroded parts and purchased parts shall not be used for assembly.

⑤ Parts should be cleaned before assembly, and should not contain any pollutants (such as iron filings, burrs, fibrous impurities, etc.).

⑥ When assembling the components, it is not allowed to use cotton yarn, paper and other fiber easy to fall off to wipe the inner cavity of the shell and the fitting surface of the parts, as well as the inlet and outlet channels.

⑦ When assembling the components, the seals with defects and beyond the valid service life shall not be used.

⑧ The symbol indicating the function of the oil port shall be clearly marked near all connecting oil ports of the component. Unless otherwise specified, the symbols of oil ports are: p-pressure oil port; t-return oil port; a, b-working oil port; l-drain oil port; X, y-control oil port.

⑨ The coating on the exposed non machined surface of components shall be uniform and uniform in color. Putty shall not be applied before spraying.

⑩ After the components pass the factory inspection, each oil port shall be sealed, dustproof and leak proof.

(3) Test requirements

① Measurement accuracy level. The measurement accuracy of component performance test is divided into a, B and C levels: a level is applicable to scientific appraisal test; B level is applicable to type test of hydraulic components, or product quality assurance test and user's selection and evaluation test; C level is applicable to factory test of hydraulic components, or user's acceptance test.

② Measurement system error. The allowable error of the measurement system shall comply with the following table.

 

Allowable error of measurement system

Measurement parameters

各测量准确度等级对应的测量系统的允许误差

A

B

C

压力(表压力p≥0.2MPa/%

±0.5

±1.5

±2.5

流量/%

±0.5

±1.5

±2.5

温度/℃

±0.5

±1.0

±2.0

转矩/%

±0.5

±1.0

±2.0

转速/%

±0.5

±1.0

±2.0

 

③ The measurement test should be carried out under steady-state condition. When the variation range of the average display value of each measured parameter meets the requirements of schedule 2, it is a steady-state condition. Under steady-state condition, all parameters (pressure, flow, torque, speed, etc.) of each set point should be measured at the same time.

④ Test fluid

a. Oil temperature: except for special provisions, the oil temperature during the test shall be 500 ℃, and the allowable variation range of steady-state condition shall comply with the provisions of schedule 2.

b. Oil viscosity: the kinematic viscosity of oil at 40 ℃ should be 42-74mm2gs (special requirements are specified separately).

c. Oil contamination: it shall not be higher than the oil contamination level specified in the use requirements of hydraulic components.

 

Allowable variation range of average display value of measured parameter

测量参量

各测量准确度等级对应的测量系统的允许误差

A

B

C

压力(表压力p≥0.2MPa/%

±0.5

±1.5

±2.5

流量/%

±0.5

±1.5

±2.5

温度/℃

±1.0

±2.0

±4.0

转矩/%

±0.5

±1.0

±2.0

转速/%

±0.5

±1.0

±2.0

黏度/%

±5

±10

±15

 

⑤ For hydraulic components with special requirements, the test conditions and requirements shall be agreed by both parties.

(4) Marking and packaging

① The product name plate shall be set at the obvious part of the hydraulic components, and the contents of the name plate shall include: name, model, factory number; main technical parameters; manufacturer's name; factory date.

② For the hydraulic components with direction requirements (such as the rotation direction of the hydraulic pump), the obvious parts of the components shall be marked with arrows or corresponding marks.

③ The following documents shall be attached to the factory packing of hydraulic components: Certificate of conformity; operation manual (including component name, model outline drawing, installation and connection dimensions, structure diagram, main technical parameters, service conditions and maintenance methods, spare parts list, etc.); packing list.

④ When packing the hydraulic components, the specified accessories shall be packed together with the hydraulic components and fixed in the box.

⑤ For the hydraulic components with adjusting mechanism, the adjusting spring should be in a relaxed state when packaging, and the exposed thread, keyway and other parts should be protected.

⑥ The package shall be solid and reliable, and shall be shockproof and moisture-proof.

⑦ In the eye-catching position on the outer wall of the packing box, the following contents should be clearly marked in words: name, model; number of pieces and gross weight; overall dimensions of the packing box (length, width and height); name of the manufacturer; packing date; name, address and arrival of the user; transportation precautions or operation marks.

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