Rancilio Silvia Boiler to Expansion Valve Fitting Lead-free brass fitting connecting the boiler to the expansion (over-pressure) valve on the newer Rancilio Silvia. No gasket is included or needed, the fitting is designed to compress and seal on its own; the copper washers are only there to position the valve on the fitting, not to seal it. SPECIFICATIONS 1/4" M BSP x 1/4" M BSP Length: 31 mm Wrench size: 15 mm Material: Lead-free brass COMPATIBILITY Fits: Rancilio Silvia (new boiler-to-expansion-valve configuration) INSTALLATION A moderate DIY job, drain the boiler before removing the old fitting, and use a 15mm wrench to avoid rounding the flats. PRO TIPS Don't add a gasket or thread tape thinking it will improve the seal, this fitting is designed to compress and seal metal-to-metal on its own, and adding a gasket can actually prevent proper seating.