When connecting PE pipes, there are generally four methods: hot melt connection, saddle butt connection, steel-plastic flange connection and electric fusion connection. The most commonly used method is hot melt connection. Hot melt connection uses a hot melt butt welding machine to heat the pipe end. After the pipe end melts, it is quickly fitted, maintaining a certain pressure, and cooling to achieve the purpose of welding. So what is the cooling time for HDPE pipe fusion?
1. Hot melt butt welding time for PE water supply pipe: The engineering pressure of HDPE pipe for water supply is different, and the wall thickness is also different. The greater the pressure, the thicker the wall thickness. According to the formula, the data obtained by the wall thickness of the PE pipe * 10 is the welding time of the pipe. For example, the wall thickness of DN110, 1.6MPa pipe is 10.0mm, then it is 10mm*10=100s.
2. The temperature required for PE water supply pipe welding: The temperature of the hot melt butt welding machine heating plate is adjusted to 200~230℃, and the general temperature is around 210°. The heating time of the heating plate is different in winter and summer, and the best melting length of the two end faces is 1-2mm.
3. Cooling time after welding of PE water pipe: Generally speaking, small diameters below DN110 need to be cooled for more than 20 minutes, and diameters above DN110 need to be cooled for more than half an hour. Also judge by hand feel, if the temperature is not very hot, it proves that the cooling time has been reached.
When connecting PE water pipes, it is very important to master the time, temperature and cooling time.
DEFINITIONS Initial Heat (Bead-up) The heating step used to develop a melt bead on the pipe. Initial Heat Force (Bead-up Force) The force (pounds) applied to establish a melt pattern on the pipe. The Initial heat force is determined by multiplying the fitting base area (in2) by the initial heat interfacial pressure (psi). Heat Soak Force The force (pounds) applied after an initial melt pattern is established on the pipe. The heat soak force is the minimum force (essentially zero) that ensures the fitting, heater and pipe stay in contact with each other. Fusion Force The force (pounds) applied to establish the fusion bond between the fitting and the pipe. The fusion force is determined by multiplying the fitting base area (in2) by the fusion interfacial pressure (psi).
Total Heat Time A time that begins when the heater is placed on the pipe and initial heat force is applied and stops when the heater is removed. Maximum heating times are shown in Table IV for both pressure (hot tapping) and non-pressure fusion applications. Cool Time The time required to cool the joint to approximately 120o F ± 10o F. The Fusion Force must be maintained for 5 minutes on 1-1/4”IPS or 10 minutes for all other pipe sizes, after which the saddle fusion equipment can be removed. The joint must be allowed to cool for an additional 30 minutes before tapping the pipe or joining to the branch outlet. Recommended minimum cooling times are shown in Table IV.
