Pressure tanks are essential for whole house applications, toilet blocks and larger pressure systems. Even basic domestic applications will benefit from the inclusion of a pressure tank. REEFE pressure tanks are manufactured with a food-grade Polypropylene Liner and a Heavy-Duty Butyl Rubber diaphragm. The brass air valve is sealed by a threaded O-ring valve cap to prevent air leaks. The threaded water connection fitting is Stainless Steel to avoid corrosion, and provides a unique water/air seal preventing leaks. There are no wetted steel parts to avoid corrosion. All the internal parts including the air valve are smooth to prevent damage to the diaphragm. The steel tank exterior is protected with a triple coat paint finish.