4 inch Tri-Clamp Lid with Ball Lock Posts, Pressure Relief Valve & Floating Dip Tube - KL05890This lid is so you can convert the 29 and 58L Kegmenters that we sell into either pressure rated fermenters or use the Kegmenters as ball lock kegs. This lid comes with a red pressure relief valve (that opens at 2. 5bar compatible thread to cornelius type PRVs). The lid has accurately machined gas and liquid posts. This lid is ideally suited to also fermenting under pressure so you can use a spunding valve adjustable pressure relief valve so you can