Spiral Wound Gaskets UK : Complete Guide to Industrial Flange Sealing, Standards & Applications When you are defining or procuring spiral wound gaskets UK industrial plant relies on stakes are high. The Health and Safety Executive (HSE) and Energy Institute have provided guidance that leakage through flange joints is still one of the main causes of hydrocarbon release incidents at UK industrial sites. The wrong gasket, or the improper installation of a gasket, can lead to a less safe process, unplanned shutdowns, and severe regulatory liability. This guide provides you with all the information you need to understand about spiral wound gaskets, what materials you need to consider using, UK and international standards for spiral wound gaskets and choosing the correct gasket for your application. What Is a Spiral Wound Gasket? Spiral wound gasket is a semi-metallic gasket made by spiral an alternating series of metal and soft filler material into a spiral shape. The outcome is a robust and effective gasket that can successfully resist harsh process media, temperature and pressure in extreme conditions in demanding industrial applications. There are usually three parts to the manufacture of a spiral wound gasket: Metal winding strip: the most popular are stainless steel 316 or other corrosion-resistant metals, which are used to provide structure and resilience. Filler material: usually flexible graphite or PTFE which fills surface irregularities on the face of the flange to form the main seal. Inner and outer rings: solid metal rings to regulate compression, prevent gasket blow out and protect winding during installation. Spiral wound gaskets are a popular gasket choice in the UK for process industries because they offer a balance between metal strength and soft filler flexibility. To get an overview of gasket types and sealing technologies, check out our Gaskets & Seals — Complete Industry Guide. How Does a Spiral Wound Gasket Work? Spiral wound gasket metal windings compress when a bolted flange joint is assembled and tightened. As the layers are wound, they will return slightly, providing a resilient seal with stress and soft filler material will be pressed into the small irregularities present in the face of the flange, creating a tight seal between the flange faces and the process fluid. The outer guide ring aligns the gasket to put it into place exactly against the flange face and avoids over compression of the winding. The inner ring offers extra blow-out protection and aids the winding on the bore side, especially during high pressure/high temperature usage. This type of resilience makes spiral wound gaskets capable of handling any amount of displacement of flanges, thermal cycling and pressure changes, which can cause other types of gaskets to leak or fail prematurely. Spiral Wound Gasket Materials: Winding & Filler Options One of the most important choices to make in the specification of a spiral wound gasket is which materials to use. The metal winding should also be compatible with the process temperature, pressure and the chemical characteristics of the process medium, as well as the characteristics of the filler material. Winding Strip Materials 316 Stainless Steel: most widely used; can be used under a variety of process conditions. The 304 Stainless Steel is used in general industrial applications in non-corrosive settings. Inconel 625: High temperature, corrosion resistant applications. MONEL 400: very good for service in seawater and hydrofluoric acid. Hastelloy C-276: in highly corrosive chemical and acid environments. Chemically-resistant: acid and alkaline service. Filler Materials Filler Material Key Properties Typical Applications Flexible Graphite Excellent heat & chemical resistance Steam, oil & gas, hydrocarbons PTFE Outstanding chemical inertness Aggressive chemicals, acids, solvents Ceramic / Mica Very high temperature resistance Extreme heat applications Non-Asbestos Fiber General sealing performance Low-to-medium pressure service For guidance on selecting the right flange specification to pair with your gasket choice, see our Industrial Flange Types, Standards & Specifications. Spiral Wound Gasket vs Ring Type Joint Gasket One of the often asked questions by procurement and engineering staff is: What is the difference between a spiral wound gasket and a ring type joint (RTJ) gasket? They are used in difficult industrial use, but each has different requirements. Feature Spiral Wound Gasket Ring Type Joint (RTJ) Construction Metal + soft filler (semi-metallic) Solid metal ring Sealing Mechanism Resilient compression sealing Metal-to-metal contact Pressure Range Medium to very high Very high / extreme Temperature Range Up to 500°C+ Extreme temperatures Flange Type Raised face, tongue & groove Ring groove flanges only Reusability Single use recommended Single use Cost Moderate Higher Typical Use Refineries, power, process plant Wellheads, subsea, HPHT Spiral wound gaskets offer the be…