During the experiment, the closed water experiment should be adopted. The size of the capsule should be matched with the pipe to be tested. All kinds of capsules must be used in the corresponding pipe, instead of replacing the large with the small. The experimental control procedure is roughly as follows:
(1) Preparation: first, stop assembling the fittings installed for closed water test and inflation, and conduct tool leakage test. Place the capsule in a bucket full of water and press it, inflate the capsule with an air cylinder, and check whether the capsule leaks.
(2) Open the inspection port of the riser, gradually feed the closed water test upward from this port for about 0.5m, and then inflate the capsule to make the capsule closely contact the inner wall of the tube without water leakage. The control staff inflates the air in the lower layer and injects water in the upper layer. Note that the capsule should not be placed at the valve of the riser pipe fittings for the following reasons: 1. There is a joint on the inner wall of the valve, which affects the tightness of water plugging. 2. In order to prevent the capsule from contracting to one side and the air pressure cannot be hit, the closed water experiment will be broken if the air inflation is inherited. As for cast iron drainage pipe, it is required to clean the sand, make the inner wall flat, and allow no burr, otherwise it will affect the water plugging and sealing, and even puncture the capsule.
(3) Inject water at the water injection port (or at the inspection port) of the floor to the floor height, and then check the water injection pipeline and pipe fitting interface one by one. If any leakage point is found, make a mark, and stop repairing after drainage; If it is a ring flexible interface, it can be repaired with water tight bolts at the leakage interface. If there is no leakage point in the water injection pipeline inspection, the water level can be stabilized. The water injection lasts for 15 minutes. It is qualified if the water injection level does not drop for 5 minutes.
(4) Deflate the closed water test, and then draw out the capsule, taking care not to damage the capsule.
(5) After the closed water test is taken out, the water should be able to drain away quickly. If the water falls slowly, it is clarified that there are sundries in the water injection pipe section, which should be cleared in time.
(6) With the method of closed water test inflation, you can also check whether the squatting toilet can leak. Place the capsule at the drainage outlet of the squatting toilet and inflate it, then inject water into the squatting toilet (the upper edge of the water level pan). Assuming the water level drops, it is clarified that there is leakage at the flushing water inlet, or the water inlet of the squatting toilet is not tightly sealed, or there is leakage in the squatting toilet itself, which should be cleaned.
(7) The water injection test shall be stopped by sections (layers), and the test results shall be recorded.
(8) The water injection test method for buried pipelines is basically the same
(9) This closed water experiment is a national patent product, and the pipeline plugging construction process and leakage reason must be investigated for the prevention of construction