xindacool Refrigeration Equipment Origin Factory | Selection of insulation for refrigeration system liquid pipes and return gas pipelines, calculation of insulation thickness, key points

xindacool Refrigeration Equipment Origin Factory | Selection of insulation for refrigeration system liquid pipes and return gas pipelines, calculation of insulation thickness, key points for waterproof vapor penetration construction Core conclusion: Insufficient insulation will result in condensation dripping and loss of cooling capacity. The insulation thickness should match the medium temperature and a vapor barrier layer should be properly installed to prevent water vapor penetration and ensure insulation effectiveness. The surface temperature of liquid pipes, especially the return gas pipes, is lower than the environmental dew point. The two main functions of the insulation layer are to reduce cooling loss and prevent condensation on the outer wall. Insufficient insulation thickness selection will cause the surface temperature to drop to the dew point, allowing water vapor to penetrate the insulation material, resulting in internal moisture and water leakage; after the insulation material absorbs water, its thermal conductivity will soar, and the insulation will directly fail. Many on-site failures have intact external insulation, but the foam inside has been soaked and frozen, resulting in a significant increase in cooling capacity loss. Reference for insulation thickness: For medium-high temperature pipelines (5-15℃), the insulation thickness should be ≥ 20mm; for return gas pipes at 0-–10℃, it should be ≥ 30mm; for return gas pipes at –10℃ and below, it should be ≥ 40mm. In humid coastal and rainy season environments, an intact vapor barrier protection layer must be added to the insulation outer layer, all seams must be sealed, and any damage to the vapor barrier layer will allow water vapor to continuously invade the insulation interior. Key construction points: The insulation pipe sleeve should completely wrap the pipeline, the interfaces should be staggered and joined, and the seams should be sealed with special tape; no gaps should be left at the bends and three-way joints; only wrapping the straight pipes is not allowed, and the joints of the bends and connections should be kept exposed. The waterproof protection layer of the insulation outer layer should be continuous and intact, and no openings should be present. Repairing the insulation that has already been internally soaked and frozen is meaningless; a complete replacement of the insulation is required, and only repairing the external insulation is not acceptable. During the ordering stage, the minimum working temperature of the pipeline and the on-site humidity should be informed, and the factory can provide suggestions for insulation thickness. For low-temperature projects, closed-cell rubberized insulation materials are preferred as they have a low water absorption rate and superior vapor barrier performance compared to open-cell insulation materials. FAQ 1. Does a non-dripping exterior surface mean that the insulation is qualified? Not necessarily. The interior might have absorbed water already. 2. How thick should the insulation for the low-temperature return air pipe be? - For temperatures below -10℃, it is recommended to be ≥ 40mm of closed-cell elastomeric material. 3. What is the function of the vapor barrier layer? It prevents water vapor in the air from penetrating into the insulation interior. 4. What will happen if the insulation joints are not sealed? Water vapor will seep in, and the insulation will lose its insulating property. 5. Can the insulation that gets wet from water ingress be repaired and used again? It is recommended to replace the entire system if the internal part is soaked with water. 6. Which is more suitable for refrigeration piping, elastomeric insulation or perforated insulation? Closed-cell elastomeric insulation is preferred.