What is the boiler hydraulic test?

Boiler hydraulic test is the strength and tightness test carried out by pressure water after boiler assembly.

When will the boiler hydraulic test be carried out?

1. After the installation of the boiler, the pressure bearing parts shall be tested by water pressure.   

2, boiler large, small repair or partial heating surface maintenance, must be conventional hydraulic test, the test pressure is equal to the maximum allowable working pressure of the boiler.The hydraulic test should be presided over by the maintenance personnel, operation and maintenance personnel to participate in.     

3, boiler hydraulic test generally two large, small repair once, according to the specific technical conditions of the equipment with the approval of the company's boiler supervision department, can be appropriately extended or shortened interval time, overpressure test should be combined with large and small repair.

When should the boiler overpressure test be carried out?

1. When the newly installed boiler is put into operation.    

2. When the boiler that has been out of service for more than one year resumes operation.   

3, boiler transformation, pressure components after major repair or replacement, such as water wall replacement pipe number in more than 50%, superheater, reheater, economizer and other parts in groups to replace, drum for major repair. 

4. When the serious overpressure of the boiler reaches 1.25 times the working pressure and above.   

5. When the heating surface is large-area deformation after serious water shortage of the boiler.   

6. Doubt the safety and reliability of the operation of the equipment according to the operation situation.

The scope of the boiler hydraulic test

1, superheated steam system: self-contained water operation platform to the main steam pressure test before the electric plug valve.

2, reheat steam system: self-cooling re-inlet water pressure test electric plugging valve to heat re-outlet water pressure test plugging valve.

3, the boiler body part of the pipeline components.

4. Drum water level gauge only participates in conventional hydraulic test and does not participate in overpressure test.

5. If Gaojia has the operating conditions, Gaojia will participate in the conventional hydraulic test, not the overpressure test.

6. The initial water pressure test of the boiler body should be carried out before the electric body of the furnace water pump is installed. At this time, the pump shell participating in the water pressure test is closed by a special water pressure blocking plate.Because the pump shell is empty, the outlet valve (10) of each furnace water pump can be opened to make the boiler evenly filled with water.

7. Before the hydraulic test in normal operation, the furnace pump should be fully filled with water.

8, overpressure test, boiler furnace pump rotating parts should wait for the completion of overpressure water pressure test, then install;The pump shell is isolated by the water pressure cover plate during the hydraulic test.

Check and prepare before hydraulic test

1, check the steam water system related to the boiler hydraulic test, its overhaul work has been completed, the work ticket is recovered, the furnace and flue are not working.

2, the drum and reheater inlet has been installed by the inspection of the accuracy of 0.5 level local pressure gauge, and the control room drum and reheater inlet pressure gauge indication calibration is correct, between the local and central control room is equipped with good communication equipment.

3, check the boiler soda water system has been reliably isolated from the steam engine (in accordance with the specific operation ticket for isolation).

4, water pressure test, the ambient temperature should be above 5℃, otherwise there should be reliable anti-freezing measures.The water temperature of the hydraulic test is generally 40 ~ 60℃, the temperature difference between the water temperature and the drum wall is not more than 28℃, and the metal temperature of the heating surface is not less than 21℃.

5, water pressure test with debrine or condensed water, pH value is about 10.0.The reheater system hydraulic test water, the content of chloride ion in the water is less than 0.2mg/L, so as not to cause high chloride ion on the transcrystalline corrosion.

6. The spring hanger of the pipeline in the range of hydraulic test should be fixed by a bolt or a positioning piece before the test. It should be temporarily used as a rigid hanger and removed after the hydraulic test.

7. The electric door of superheater and reheater reducing warm water is removed from interlock.

8. Contact maintenance to install temporary pressing device on all safety doors, release the electromagnetic relief valve, and close the manual isolation door to prevent action during the water pressure test.

9. Before entering the water, the sundries in the pressure bearing parts of the boiler shall be cleaned up by maintenance.

10, according to the pump operation rules, do a good job of electric feed water pump inspection and preparation.

11. Check the correct state of the boiler valves according to the hydraulic test check card.