JB/T 9076-2016Reciprocating cryogenic liquid pumps - Specification (English PDF)

3.1 General

3.1.1 The reciprocating pump shall comply with the provisions of this Standard, and shall be manufactured according to the drawings and technical documents approved by the prescribed procedures, or as required by the contract.

3.1.2 Motors and electrical devices shall meet the regional level requirements stipulated in the contract.

3.1.3 The connection between the pump head of the reciprocating pump and the pipeline, and the connection between the base and the foundation shall be able to avoid deformation affecting the use due to changes in temperature and pressure.

3.1.4 During the operation of the reciprocating pump and during the termination of pumping, the cold end part and the transmission case shall be polluted by moisture, dust and foreign matter as little as possible.

3.1.5 All pipeline installations and support settings, etc., shall be able to withstand the total load of temperature stress caused by repeated changes in medium temperature and additional stress caused by connecting pipelines for a long time.

3.1.6 In the structure of the reciprocating pump, there shall be no dead angles that are prone to air blockage, and the outlet of the reciprocating pump shall not be arranged downward.

3.1.7 Spare parts and consumable parts of reciprocating pumps shall have good interchangeability and shall meet the requirements of this Standard.

3.2 Performance requirements

3.2.1 The reciprocating pump shall work normally according to the performance parameters specified in the drawings. Under rated operating conditions, the performance indicators shall meet the requirements in Table 1.

3.2.2 When liquid compressibility is considered, the volumetric efficiency shall be reduced, and the user shall provide the compressibility data of the medium.

3.2.3 The reciprocating pump shall work normally and operate reliably when the discharge pressure deviation increases to 105% of the rated discharge pressure value.

3.4 Non-destructive testing

Non-destructive testing shall comply with the provisions of NB/T 47013. Materials for forged pressure-bearing parts (including shafts) shall be subjected to ultrasonic testing, which shall not be lower than the requirements of level II in NB/T 47013.3. The pressure-bearing butt welds shall be subjected to radiographic testing, which shall not be lower than the requirements of level II in NB/T 47013.2; the fillet welds shall be subjected to penetrant testing, which shall not be lower than the requirements of level II in NB/T 47013.5.

4.1 Test methods

4.1.1 Water is prohibited in the performance tests of reciprocating pumps, and cryogenic media such as liquid nitrogen shall be used for performance tests; liquid oxygen should not be used as the test medium.

4.1.2 Flow measurement

Use the flow meter method, inflation bottle measurement method or other equivalent methods, such as the gas flow meter detection and conversion method after the on-site vaporizer. Test flow deviation shall meet the requirements of 3.2.1. The specific method is as follows:

a) Flow meter method

1) Applicable to the performance test device equipped with a flow meter.

2) After the reciprocating pump is in normal operation and reaches the set speed, collect the flow data, and take the average value of the three sets of data as the actually measured flow of the reciprocating pump.

b) Inflation bottle measurement method: After the discharge pressure of the reciprocating pump is stabilized, completely vaporize the cryogenic liquid in the vaporizer, and fill it into the metering container; record the inflation time t, and measure the pressure p1, p2 and temperature T1, T2 in the container before and after inflation; calculate the flow rate of the reciprocating pump according to Formula (1).

Where: q - flow rate of the pump, in liters per hour (L/h):

V - capacity of the inflation bottle, in liters (L); t - total time of measurement, in seconds (s):

phi - coefficient, the volume occupied by each liter of cryogenic liquid vaporized into gas at 0 °C and 0.101 325 MPa (absolute), in cubic meters (m3); p2 - final pressure of the inflation bottle, in megapascals (MPa);

T2 - final temperature of the inflation bottle, in Kelvins (K):

P1 - initial pressure of the inflation bottle, in megapascals (MPa);

T1 - initial temperature of the inflation bottle, in Kelvins (K).

4.1.3 Outlet pressure test

After the reciprocating pump works normally and runs to the specified speed, close the outlet valve, observe the pressure gauge of the outlet pipeline of the reciprocating pump, and test whether it reaches the specified outlet pressure value and runs stably. Be careful not to shut down the valve.

4.1.4 When the reciprocating pump reaches the specified outlet pressure and flow rate, use a dynamometer or the current and voltage calculation method to test the shaft power.

4.1.5 Required net positive suction head test for reciprocating pumps:

When the reciprocating pump reaches the specified rated speed and rated pressure, while maintaining the differential pressure not lower than the rated differential pressure, gradually reduce the suction pressure of the pump until the flow rate is 5% ~ 10% lower than the normal flow rate; test at not less than 5 points. When the reciprocating pump is close to cavitation, the interval between test points shall be appropriately reduced. At each suction pressure test point, the values of medium temperature, flow rate of hours. When the factory does not have low temperature operation conditions, it is allowed to be carried out at the user's site. Type inspection items are as follows:

1) performance (flow rate, discharge pressure, suction pressure, shaft power, number of reciprocations, net positive suction head of the pump, etc.) determination;

2) vibration measurement;

3) noise measurement;

4) wear measurement of piston ring and guide ring.