These instruments are often referred to as “Loaders” because of their many years of extensive use maintaining constant, extremely accurate pressure control in the “loading” of dome regulators. However, their accuracy, trouble-free performance, and versatility have led to hundreds of other applications in static, mobile and airborne services. They are used in component testing, hydraulic and pneumatic operator systems, safety relief valve actuation, critical rocket fuel transfer and pressurizing problems encountered in missiles and space vehicle projects, to name only a few.