Valve Stem Isolation (VSI)

Naval ships require several thousand valves ranging in size from to 10 in pipe diameter. Many of these valves carry seawater or other corrosive fluids. The valve packing gland is used to prevent water from leaking past the stem. The corrosion occurring on the valve stem can compromise the packing gland and lead to a leaking valve. The packing is a graphite bushing that is relatively soft and capable of sealing around the valve stem when compressed by a packing nut. The current procedure to stop a leak through the valve stem is to simply tighten the packing nut and compress the packing more. However, severe corrosion of the stem causes the valve to leak and the packing nut can only be tightened so many times before the valve is rendered unusable and requires maintenance. To solve this problem, Mide developed a method to isolate the fluids from entering the valve stem. Mides Valve Stem Isolation design will prevent fluids from entering the valve stem and prolong the life of a valve without affecting performance. This solution significantly reduces the Total Ownership Cost (TOC) of the valves.