PVC lay flat hose is a hose for transporting high pressure water or foam and other flame-retardant liquids. Traditional PVC lay flat hose is lined with rubber and linen knitted fabric is wrapped on its outer surface. Advanced PVC lay flat hose is made of polyurethane and other polymer materials. Both ends of the PVC lay flat hose have metal joints, which can be connected to another rubber PVC lay flat hose, polyurethane PVC lay flat hose, to extend the distance or to connect the nozzle to increase the liquid injection pressure. The inner diameter of PVC lay flat hose was measured by plug gauge. The plug gauge is made of metal and its structure is shown in the following figure. When measuring the inner diameter of PVC lay flat hose test method, the two ends of the sample are sheared smoothly, and then the two ends are measured with plug gauge. PVC lay flat hose weighs the sample. The ratio of the weight to the length of the sample is the weight per unit length of PVC lay flat hose. One end of the sample is connected with the water source and the other end is closed to keep the sample straight. Fill the sample with water in 2 minutes, then uniformly raise the pressure to 1.1 working pressure in 1 minute and hold the pressure for 16 minutes. From the 16th minute of pressure holding, the water collected by the flume specified in Article 3.6B is the seepage amount of the sample. During the test, tie lines or other appropriate methods should be used on the sample to prevent the seepage from entering the tank beyond the test length of 1 meter, and make all the seepage within the test length gather into the tank. In addition, the sample should not be touched. Starting from the 16th minute of holding pressure, check whether there are holes in the sample. The determination of the hole is based on whether the water column is ejected or not. The blasting pressure of PVC lay flat hose is straight blasting pressure. After the test of water seepage, the pressure is evenly raised to the prescribed straight blasting pressure, holding pressure for 5 seconds, and the sample can not be broken. The boost time is 30-60 seconds.