A broad range of connections between components and pipes consisting of two parallel surfaces (flanges) with a gasket between them. In specialty gases installations the two parallel surfaces are called glands and they are held together with female and male nuts. The gasket is made of metal, such as stainless steel. The metal gasket face seal fitting is commonly known as VCR® which is a trademark of Swagelok. For specialty gases installations the most common size is 1/4".