Hylomar Advanced Formulation HV Sealing Compound 300 ml

Hylomar Advanced Formulation HV is a solvent-free sealing compound that remains permanently plastic without curing. Thanks to its high viscosity and thixotropic structure, it stays in place without running and creates a seal by filling microscopic surface irregularities, especially on close-tolerance flange faces. Its non-hardening nature is an advantage in maintenance work where repositioning during assembly and later disassembly may be required. The 300 ml cartridge pack is suitable for controlled application both by hand and with metering equipment.

What is Hylomar Advanced Formulation HV sealing compound?
This product is a non-setting, non-drying compound developed to support the gasket surface as a gasket dressing and to provide an additional sealing layer in flange joints. It is manufactured by Hylomar Ltd., originating from the United Kingdom. In joints exposed to impact, vibration and differential thermal expansion after assembly, its non-setting structure helps reduce the risk of cracking or embrittlement. By making gasketed joints easier to align and allowing parts to be assembled immediately or later, it adds flexibility to service processes.

Technical composition and performance characteristics of Advanced Formulation HV
Advanced Formulation HV is a solvent-free, high-viscosity, thixotropic gel-type, non-running, non-setting paste. A typical operating temperature range of -55°C to +250°C is stated, enabling use across a wide temperature window in engines, gearboxes and general industrial equipment. The product is blue; its density is reported at approximately 1.16–1.21, and its viscosity at 25°C is around 1,000,000–1,100,000 cP, supporting its gap-filling capability. Resistance is targeted against automotive fluids, fuels, mineral oils and synthetic lubricants, helping maintain sealing performance in oil-contaminated flange connections.

Application method and assembly practice
The product can be applied from the 300 ml cartridge using hand pressure with a suitable applicator, and it can also be used in automatic dispensing systems. After applying a thin, continuous film to the mating surface, parts can be assembled immediately, or assembly can be postponed without time pressure; this supports the concept of unlimited assembly time. A typical surface requirement of approximately 3.0 µm Ra roughness is stated, which can help achieve efficient results particularly on machined flange faces. Because the material does not harden after application, it facilitates cleaning of surfaces during service disassembly and simplifies reassembly processes.

Surface compatibility and typical use cases
Hylomar Advanced Formulation HV is positioned for use on gasket surfaces and close-tolerance flange joints, alongside all types of gaskets, to enhance sealing capability. Typical applications include sealing cylinder liners into engine blocks, cylinder head components, electric motor covers and fuel injector fittings—assemblies that often require serviceability. This range indicates suitability for points requiring flange sealing in automotive and heavy-duty engines, as well as maintenance, general engineering and industrial production lines. Its non-drying nature helps accommodate micro-movements on joint faces in equipment operating under vibration and shock.

Storage, safety and key benefits in use
When stored in its original, unopened packaging under suitable conditions, a typical shelf life of 3 years is stated; cool storage conditions are recommended. Its solvent-free formulation is advantageous in terms of volatile emissions, and SDS documents report a VOC value of 0 for the product. From a safety perspective, according to the available SDS, the mixture is not classified as hazardous under CLP/OSHA; however, standard industrial hygiene practices such as avoiding skin/eye contact and using appropriate gloves/eye protection are recommended. Overall, this makes it a controlled and repeatable sealing solution for both production-line assembly and maintenance operations.