Piston Gauge YS-600

0.05 class piston pressure gauge (hereinafter referred to as the pressure gauge) is used for verifying 0.2 class piston pressure gauges and precision pressure gauges. Performance characteristics: Complies with the new regulations JJG59-2007 "Piston Pressure Gauge" and JJG99-2006 "Weights" national metrological verification regulations.

II. Working Principle and Basic Structure

The working principle of the pressure gauge is based on the weight of the piston itself and the weight of the special weights added to the piston, which act on the piston area to generate pressure that balances the pressure generated in the hydraulic container.

The pressure gauge consists of two parts: the test pump and the measurement system.

III. Technical Data

Main Performance Parameters of Supporting Products

Table1

The buoyancy of the load-bearing rod (including the piston head) of the YS-250 and 600 piston pressure gauges immersed in the working fluid is 5.6g.

For the YS-6 piston pressure gauge, the liquid column difference H between the bottom of the piston and the center of the calibrated gauge, with an outer diameter of the gauge case of φ150 mm, H=109 mm; with an outer diameter of φ160 mm, H=119 mm; with an outer diameter of φ250 mm, H=169 mm. The correction formula is △P=Hγ, where △P is the pressure generated by the liquid column difference, and γ=0.88 g/cm³ is the specific gravity of transformer oil.

For φ250 mm, H=169 mm, the correction formula is △P=Hγ, where △P is the pressure generated by the liquid column difference, and γ=0.88 g/cm³ is the specific gravity of transformer oil.

IV. Acceptance and Storage

1. Upon receiving the boxed pressure gauge, the user should first check whether the packaging of the pressure gauge is intact; if there is any damage, the cause should be identified immediately.

2. After opening the box, remove the padding and check whether the appearance of the pressure gauge is intact, and whether the manual and certificate of conformity are complete. If there is any deficiency, notify our factory immediately.

3. The pressure gauge should be stored indoors, with an ambient temperature of +5~35°C, relative humidity not exceeding 80%; the surrounding air should not contain harmful impurities that could corrode the pressure gauge.

V. Installation and Use

1. The pressure gauge should be placed on a workbench that is convenient for operation. Use the adjustment screws (4) to calibrate the level, ensuring that the bubble in the bubble level is in the center position.

2. The working environment temperature of the pressure gauge should be 20±2°C, and the surrounding air should not contain corrosive gases.

3. The weights should be placed in a dry location.

4. Before use, first clean all parts of the pressure gauge with oil, then fill the hand pump and the inner cavity of the measurement system with the pressure transmission medium (the pressure transmission medium must not contain impurities or dirt), and expel the air from the inner cavity.

5. Rotate the handwheel of the hand pump to check if the oil path is clear: if there are no issues, install the precision pressure gauge to be verified.

6. Operating steps:

(1) Open the oil cup (9), rotate the handwheel counterclockwise to fill the cylinder of the hand pump with oil.

(2) Close the oil cup (9), open valves (6), (7), and (8), rotate the handwheel clockwise to generate initial pressure, raising the base plate until it aligns with the upper end of the indicator plate. See figure.

(For model YS-6, until the engraved line on the piston rod coincides with the red paint line.)

(3) Increase the weight of the weights to generate the required test pressure. While adding weights, continuously rotate the handwheel to prevent the base plate from descending; during operation, the base plate and weights must be rotated clockwise at an initial angular speed of not less than 30 rpm to overcome the effects of frictional resistance.

(4) After the inspection is completed, rotate the handwheel counterclockwise to gradually remove the weights; finally, open the oil cup and remove all weights.

7. The actual mass of the weights, base plate, and piston as shipped from the factory is calculated based on the standard gravitational acceleration. However, if the gravitational acceleration at the location of use differs from the standard gravitational acceleration by more than 0.0005 m/s², the mass must be corrected before use. The corrected mass for YS-6 and YS-60 is calculated as follows:

Where: ｍ－Mass of the special weights, including the base plate device and piston (kg);

Ｐ－Measured pressure value (Pa);

Ａ＇－Effective area of the piston (m²);

ｇ－Standard gravitational acceleration at the time of factory manufacturing (9.80665 m/s²); when correcting at the location of use, it is the local gravitational acceleration (m/s²);

ρａ－Air density (1.2 kg/m³);

ρｍ－Material density of the special weights, base plate, and piston (steel is 7.8×10³ kg/m³, aluminum is 2.7×10³ kg/m³). The corrected weight for YS-250 and YS-600 is calculated as follows:

Mj--- Mass of the j-th weight loaded in sequence, kg;

Pj--- Pressure value generated by loading the j-th weight under reference temperature and standard gravitational acceleration, Pa;

A'o--- Effective area of the piston of the verified piston pressure gauge at zero pressure and reference temperature, m²;

ｇ－Standard gravitational acceleration at the time of factory manufacturing (9.80665 m/s²); when correcting at the location of use, it is the local gravitational acceleration (m/s²);

λ－Pressure deformation coefficient of the piston and cylinder assembly, Pa⁻¹; λ=2.8×10⁻¹² (Pa⁻¹);

j－Loading sequence of the weights.

β－Deformation coefficient (Pa⁻¹), β=2.8×10⁻¹² (Pa⁻¹);

8. When the usage environment temperature of the 0.05 class pressure gauge exceeds 20±2°C, pressure correction should be performed according to the following formula:

9. △P=P(a1+a2)(20-t) Where: P－Measured pressure (Pa);

a1; a2－Linear expansion coefficients of the piston rod and cylinder materials (copper is 0.0000167, copper is 0.0000105);

t－Ambient temperature (°C).

9. When using the pressure gauge, the piston rod, piston cylinder, base plate, and weights must be used as a set according to the same factory serial number of the pressure gauge and cannot be interchanged.

VI. Maintenance and Repair

1. Except for the piston rod and piston cylinder, which are precision components and should not be disassembled casually, other parts of the pressure gauge should be cleaned regularly. During cleaning and installation, care must be taken to prevent dirt or cloth fibers from entering.

2. The oil must be filtered and must not contain impurities or dirt; after a certain period of use, it must be replaced with new oil.

3. When not in use, cover with a dust cover to prevent dust from entering the pressure gauge.

4. After one year of use, it must be sent to a metrological authority for re-verification.

5. The pressure gauge comes with 5 leather cups as accessories. If there is leakage at the hand pump port, loosen the compression nut, manually rotate the screw counterclockwise to remove it, take out the old piston part, replace the leather cup, and ensure that the replaced leather cup can rotate freely radially.

VII. Ordering Information

When ordering, must specify: model, name, and accuracy class.

Note: 1 MPa = 10⁶ Pa; 1 m² = 10⁴ cm²