How to Operate the Pressure Vessel Hydraulic Test?

 The pressure vessel hydraulic test shall be presided over by the person in charge of the maintenance. The operation person shall be responsible for the operation. And the maintenance person shall be responsible for the inspection. 

Hydraulic Test Process

  First of all, the pressure vessel hydraulic test plug the inlet and outlet of the main equipment with blind plates or flange covers. Then use the electric pump to fill the water. After the water is filled to the visible water level of the steam drum. Furthermore, the superheater will be used to the second stage. And desuperheating water pipe is reversed and filled with water. Next, the water supply speed is not less than 2 hours in summer and 4 hours in winter. When the water temperature is close to the temperature of the pressure vessel wall. So the water supply speed can be appropriately increased.

Hydraulic test of the pressure vessel of the reheating system

In addition, injecting water to the reheating system to increase the pressure through the accidental spray of water from the reheater. The pressure should be increased slowly.

When the pressure is below 1MPa, the pressure rise speed is less than or equal to 0.1MPa/min. When it reaches 1MPa, stop and check. And keep the pressure rising for 15 minutes after the pressure is stabilized. The pressure rise speed is less than or equal to 0.3MPa/min. After rising to the working pressure of 4.4MPa stop the pressure increase. And keep the pressure stable. And conduct an overall inspection of the reheater system. After there is no abnormality, increase the pressure to the hydraulic test pressure of 6.6MPa. And keep it under this pressure for 5 minutes. After the hydraulic test is qualified. Then the pressure will be reduced to work pressure, water discharge and pressure relief. The pressure reduction rate is 0.3MPa/min.

When water continuously overflows from each air door, close each air release door according to the direction of water flow. And then increase the pressure. During the water supply process, closely monitor the changes in the water level. And check whether the components are leaking. And whether the expansion of the heated surface is normal. At last, if an abnormality is found. The cause should be immediately identified and eliminated.

Main Steam The Pressure Vessel System Water Pressure Test

Using the superheater desuperheating water regulating door to increase the pressure. Because the pressure increase should be slow. The pressure increase speed below 9.8MPa is ≤0.3MPa/min. When the pressure rises to 2MPa, the pressure increase is suspended for inspection. If the pressure is abnormal. Continue to increase the pressure after 15 minutes of stabilization.

When the pressure is increased to 5.88MPa, pause the pressure increase and observe the pressure change. If there is no abnormality, continue to increase the pressure to 9.8MPa. And then increase the pressure to ≤0.2MPa/min. At 11.77MPa. Next the pressure increase is suspended, and check for abnormalities. After there is no abnormality. Continue to increase the pressure to the working pressure of the pressure vessel to 19.79MPa. Then close the water inlet valve after 5 minutes of stabilization. Record the pressure drop within 5 minutes after the water inlet valve is closed. And notify the maintenance for overall inspection.

Overpressure Test

If the overpressure test is performed, the steam drum water level gauge should be output. After the check is normal, continue to increase the pressure to the overpressure test pressure of 29.69MPa at the same speed. Then hold for 30 minutes. And release the pressure at a rate of 0.3MPa/min with a trap .When the working pressure of the pressure vessel  is reached. Close the trap, maintain the normal test pressure. And conduct an overall inspection.

After the water pressure test is over, use a continuous drain or trap to release the pressure at a rate of 0.3 MPa/min. When the pressure drops to 0.2MPa, open the air gates and traps to drain the water. If the pressure vessel is ready to be put into operation and the water quality is qualified. It can be put to the ignition water level. Otherwise all the water should be drained and refilled. The superheater, main steam pipe, and reheater should drain the water collection. Notify the maintenance to lift the safety full door pressing device. If the pressure vessel is not put into operation within a short period of time, close the pressure relief door. And perform maintenance in accordance with the shutdown maintenance regulations.

About STRENGTH Equipments

Taian STRENGTH Equipments Co., Ltd is the professional pressure vessel designer, manufacturer and exporter dedicated in supplying finest quality industrial autoclave, storage tank and dish head products and solutions to worldwide customer over 20 years. We have over 80 talented research and development experts, 2 million square meters manufacturing factory and more than 50 sets large-scale manufacturing machines.  Our annual industrial autoclave and storage tank output can reach over 300 sets, dished head output can reach over 3000 sets.

STRENGTH Equipments is not only manufacturing high quality industrial autoclaves, storage tanks and dished ends but also providing custom product design, fabrication and after-sale service.  ODM, OEM are also available. If you have any questions or inquiries,  please fill and submit the following form, we will reply as soon as possible.