the 4 1/2″ process gauge is designed for those severe service applications where operator safety is a factor. This solid front gauge is equipped with a solid wall separating the indicating dial from the bourdon tube and a blowout back which will release from the case if the bordon tube should rupture. Available with phosphor bronze/brass or 316stainless steel internals, this gauge is ideally suited for the requirements of the process, power and chemical industries. This high quality gauge offers the benefit of field filling without any additional kits or accessories.