Insulating steam pipes is to prevent heat loss. The terminal pressure of the same steam pipes insulated or not insulated is different. Heat loss affects the temperature and pressure of the steam.

Insulated conveying pipelines are more energy-efficient than un-insulated ones. The energy loss after insulation is only about one-tenth of that of un-insulated pipelines, which prevents excessive condensate from forming during steam flow along the pipeline. Of course, insulation also addresses safety concerns. Therefore, insulation is necessary.

The temperature of steam is related to its pressure. Poor insulation could potentially affect the quality of the steam at that time.

Insulation Techniques for Steam Pipe

When the thickness of the insulating layer exceeds 100mm, it should be constructed in two layers or more, layer by layer.

2. The gap width of the interlocking thermal insulation products shall not exceed 5mm. The gaps should be filled with asbestosis lime mortar and tightly constructed. A layer of asbestosis lime mortar 3-5mm thick should be applied to the tiles, and the joints should be staggered during construction. When using more than two layers of insulation products, the joints within the same layer should be staggered, and the inner and outer layers should be pressed together, with the overlapping length not less than 50mm. Each tile should be secured with two galvanized steel wires or bands, and spiral binding methods should not be used.

The pipe end or right blind plate area should be insulated.

How to achieve effective insulation for steam pipelines, and how to select the appropriate insulation materials?

The selection of insulation materials for steam pipelines requires compliance with the pipeline insulation standards. According to Article 7.9.3 of GB50019—2003 "Code for Design of Heating, Ventilation, and Air Conditioning," the insulation materials for equipment and pipelines should be chosen first based on their low thermal conductivity, high moisture resistance factor, low water absorption rate, low density, and high overall economic benefits. The insulation material should be non-flammable or flame-retardant; the thickness of the pipeline insulation layer during heating should be determined by the economic thickness calculation in GB8175 "Guidelines for Design of Insulation for Equipment and Pipelines."

Many thermal insulation materials on the market meet the requirements of low thermal conductivity, high moisture resistance, and low water absorption, such as rubber and plastic boards, glass wool pipes, rock wool pipes, and aluminum silicate thermal insulation cotton. However, for steam pipeline insulation, the materials currently used are still rock wool, glass wool, and polyurethane.

Rockwool Pipe

Rock wool pipes are primarily made from basalt and other stone materials, classified as A1-grade thermal insulation materials. They feature low thermal conductivity, excellent insulation properties, and good hydrophobicity. In addition, rock wool pipes have a fibrous structure, capable of reducing environmental noise with great noise reduction effects. They are suitable for insulating boilers or equipment pipelines in industries such as petrochemicals, metallurgy, shipping, and textiles.

Glass Wool

Glass wool boasts excellent molding effects, with low density and low thermal conductivity. It also features excellent chemical stability, is resistant to corrosion of metal pipes, and has moisture-proof and hydrophobic properties. In addition, glass wool is suitable for insulation and noise reduction systems such as interior partition walls and ceilings.

Polyurethane Tube Shell

Polyurethane, as an insulating material, differs in structure from rock wool and glass wool, which are open-celled materials, while polyurethane pipe sleeves are closed-cell foamed structures. In terms of flame retardancy, polyurethane belongs to B1-grade insulating materials. However, the thermal conductivity of polyurethane insulated pipe sleeves is lower than that of rock wool and glass wool, making them superior in insulation performance. Besides steam pipelines, polyurethane insulation materials are widely used in refrigeration systems for cold storage and cold chain applications.

Installation Tips for Steam Pipe Insulation Materials?

Prior to trenching, the anti-corrosion coating on the surface of the pipeline must be carefully inspected. Any damage to the coating should be addressed promptly.

Ensure pipeline design axis and slope during pipeline connection.

Three, pre-insulated pipe sections can be individually suspended into the trench for installation, or 2 or more sections can be organized for welding before hoisting. When the length of the welded pipe sections is long, it is advisable to use two or more cranes to lift and lower the pipe, with the lifting points determined based on balance conditions. It is strictly prohibited to push the pipes directly into the trench.

Upon completion of the welding for the working steel pipes and upon passing the inspection, the insulation and jacket pipe connection work for the joints can be processed. First, a mold can be set up for polyurethane foaming, followed by sealing the joint section with heat shrinkable tape, with each end and straight pipe overlapping 100mm. Alternatively, the jacket pipe can be first welded and, after passing the sealing inspection, a hole can be made for foaming.

Upon completion of the day's engineering work, the pipe ends should be sealed with a blind plate to prevent mud and water from entering the pipes.

Six: Pre-insulated pipes are available in three installation methods: cold installation, hot prestressed installation, and one-time compensator installation.

Section 7: Cold installation involves directly connecting the sections of the pipe segments and, after passing the quality inspection, backfilling according to standard procedures.

Step 8: Heat-stressed installation involves pre-heating the pipeline to 60% of the working temperature before welding, followed by backfilling and compaction.

Nine: The compensator must be welded when the pipeline reaches 60% of its working temperature, followed by backfilling and compaction.