Filtering apparatus with modular filter elements

Filter apparatus constructed of metallic tubular modular interchangeable filter elements for filtering fluids having a high viscosity, a high temperature and a high pressure comprising:

• A. a plurality of filter means including a plurality of tandemly threadably interconnected metallic tubular modular filter elements, each of said metallic tubular modular filter elements including:
• 1. a metallic filter member including a perforate tubular member and a filter media of metallic fiber;
• 2. a first metal end fitting having a first metal surface and being permanently affixed to one end of said tubular member, and having male threads formed of a first type of stainless steel;
• 3. a second metal end fitting having a second metal surface and being permanently affixed to the other end of said tubular member, and having female threads formed of a second type of stainless steel;
• 4. said first and second end fittings adapted for threadably mating with each other with said first and second metal surfaces on adjacent elements in metal-to-metal sealing engagement when said modular filter elements are tandemly interconnected to form a filter means, said metal-to-metal seal being the only seal between adjacent modular filter elements;
• and
• 5. said threaded portions of said first and second fittings being constructed of dissimilar stainless steel non-galling metals;
• B. a metal header assembly defining a plurality of threaded recesses adapted for threadably receiving said first end fitting on one of said modular elements;
• C. a metal base assembly including plug means adapted for receiving and retaining said second end fitting on another of said modular elements;
• and
• D. a metal housing surrounding said header and base assemblies with said plurality of filter means supported therebetween.