An important issue with polyurethane insulation pipes is to ensure proper waterproofing, which is also an important aspect that many construction sites overlook. So next, let's take a closer look at the waterproofing workflow of polyurethane insulation pipes.
Step 1: Appearance quality inspection of polyurethane insulation pipes. One of the simple and widely used inspection methods is the appearance design inspection of welded joints, which is an important part of finished product inspection. The key is to detect defects on the surface of the weld and deviations in length. It needs to be inspected through observation and using tools such as standard templates, gauges, and magnifying glasses. If defects can be seen on the surface of the weld, there is a possibility of defects inside the weld.
Step 2: Use physical methods to inspect polyurethane insulation pipes. This method is a method of measuring or testing using some physical phenomena. The inspection of internal defects in materials or workpieces is carried out using non-destructive testing methods. Non destructive testing includes ultrasonic testing, penetration testing, radiographic testing, magnetic testing, etc.
Step 3: Strength inspection of pressure vessels. In addition to sealing tests, pressure vessels also need to undergo strength tests. There are two commonly used methods: water pressure testing and air pressure testing. They all tested the fineness of welds on containers and pipelines with polyurethane insulation pipes working under pressure. Air pressure testing is more sensitive and faster than water pressure testing. After testing, the product does not require drainage treatment, making it particularly suitable for products with difficult drainage. However, the danger of testing is greater than that of water pressure testing. During testing, it is necessary to follow appropriate safety measures to prevent accidents from occurring.
Step 4: Static water test. Each polyurethane insulation pipe should undergo a hydrostatic pressure test and must not leak. The test pressure is calculated according to the formula P=2ST/D, where S is the test stress in MPa for hydrostatic testing. The test stress for hydrostatic testing is selected based on 60% of the specified yield value of the corresponding steel strip standard (Q235 is 235Mpa). Pressure stabilization time: D<508. The test pressure should be maintained for no less than 5 seconds; D ≥ 508, the test pressure shall be maintained for no less than 10 seconds.
