In the application field of Shanghai hot melt glue machine, non-adhesive sealant is mainly used for the main body of the ship (diesel, steam engine and gas turbine, etc., which is currently the most diesel engine), the cover or flange of the turbine and other equipment. Isostatic binding site. Although the seals of many pipelines and hull structures on ships can also be used as non-adhesive sealants, due to the harsh working conditions, adhesive sealants are usually used for some parts that are not frequently disassembled.
1. Seal of power machinery
The ship's power machinery mainly consists of turbines and diesel engines. The seals of these machines are static seals. Since the ship is subjected to repeated stresses generated by wind and waves from different directions and external forces of vibration of the power machine while driving, this requires the sealant layer to have good viscoelasticity, vibration resistance and creep resistance. Therefore, semi-dry viscoelastic and non-dry adhesive sealants are mostly used, and less or no peeling and dry fixing sealants are used. For example, in the turbine, the reduction gearbox joint surface, the pump gear cover and the body joint surface, the bearing cover surface, and the transmission joint surface are generally not adhesive sealants; the control valve joint surface and the thrust bearing joint surface are commonly used for high temperature resistance. Adhesive sealant; common non-solvent adhesive sealant for cooling water pump cover. Cylinder head and cylinder joint surface of cylinder head and cylinder sleeve, and suction pipe joint surface are commonly used for high temperature and non-dry adhesive type. Sealant; semi-dry viscoelastic sealant is commonly used on the flange surface of the compressor; the flange surface of the cooling water pipe, the joint surface of the thrust bearing, the joint of the machine head and the joint surface of the frame, and the joint surface of the transmission are usually non-dry adhesive sealant. ; fuel tank joint surface, blast cover, often dry fixing sealant. In addition to turbines and diesel engines, other machinery also requires effective sealing, such as vaporizer cover, pump joint, feed water heating cover, oil heater cover, blower pipe flange face, freezer condenser cover, winch motor Bonding surface, air cooler cover, seawater filter flange face, suction pump flange face, etc. Among these machines, in addition to the high-temperature non-adhesive sealant for the vaporizer cover and the solvent-free dry adhesive sealant for the pump joint surface, the semi-dry viscoelastic sealant is generally used. The sealing picture of the piping system 4.png In the ship piping system, the adhesive type elastic sealing glue is generally used. The ship pipeline system mainly includes steam pipes, water pipes, drain pipes, fuel pipes, lubricating oil pipes, freezing liquid pipes and sea water pipes, crude oil pipes, and liquefied petroleum gas pipes. Within the working conditions of -40 to 510 ° C and atmospheric pressure to 8.OMPa, the sealing can only be completely ensured by the adhesive type sealant, and the disassembly is difficult, so in some of the more severe joints, it is often taken In combination with the solid gasket, the solid gasket used is mostly rubber type and rubber-asbestos type. For example, steam pipes are commonly used with elastic sealant and metal, asbestos and other gaskets. Silicone elastic sealant can also be used. Air hoses, fuel pipes, lubricating oil pipes and water supply pipes can be used as general elastic sealants. For pipes with small pipe diameters (eg d=30~50mm), anaerobic sealant seals are generally used. Pipes using anaerobic sealant can withstand 30MPa water pressure or 1OMPa nitrogen pressure. If threaded connection is used, the pipe with a diameter of 130mm can withstand 15MPa nitrogen pressure, and generally can save the solid gasket. Sealing tape or non-adhesive sealant does not require too much external force during construction, but requires high processing precision for the joint surface.
The fixed sealing of the hull door and window frame members, the gap sealing of decks, concrete floors, deckboards, etc., as well as the commonly used adhesive sealants such as insulation and sealing of refrigeration systems, machine rooms, warehouses, etc. In addition, many doors and windows are made of light alloy materials (such as aluminum alloys). In order to prevent electrical corrosion between them and the hull steel, sealing is also required at the contact points. The sealing glue for the door and window parts is mainly a two-component or one-component room temperature vulcanized polyisobutylene and a polysulfide elastomeric sealant. In addition to the elastic sealant, the sealing of the door and window frame members can also use a hot melt glue machine, but special coating equipment is required during construction, which limits its application to some extent. In the past, the sealing gap of the ship's wooden deck was mostly made of hemp-asphalt material. Although the price is lower, the construction process is backward and the effect is not satisfactory. Elastomeric sealants and hot-melt sealants have been gradually used, especially two-component room temperature vulcanized polyurethane elastomer sealants. Sealing and caulking of wooden ship bodies, as well as sealing and caulking of large ship cement floors, interior decorative panels (such as marble slabs, metal plates and plastic veneers), ceramic tiles, etc., can also be used at room temperature vulcanized polyurethane elastomeric sealants. The sealant of the refrigerated warehouse on the ship needs to withstand low temperature (up to -30~-20°C), moisture proof and waterproof. Most of them use polysulfide elastic sealant or polyurethane elastic sealant. For shaft systems, bearing systems, various pumps and other systems, solid sealing materials are generally used.
