Duplex Filter for Industry & Business
PURPOSE
Kraissl pipeline strainers and filters protect pumps, nozzles, valves, heat exchangers and other expensive pipeline equipment from harmful contamination by catching dirt and debris.
APPLICATION
Kraissl duplex strainers and filters provide a simple, cost effective way to separate particle impurities from fluid systems. Duplex strainers are ideal for applications where continuous flow must be maintained, with no flow interruption for basket cleaning.
Kraissl strainers are listed by Underwriters Laboratories, Inc. (U.L.), and are individually tested to U. L. quality control specifications. These cast pipeline strainers are manufactured according to international standard A.S.T.M. F1199 for use in industrial and marine applications.
DESIGN SPECIFICATIONS
Model 72AF and 72AFH series three piece duplex strainers are furnished in both standard or high pressure models with flanged port connections. The center valve section or side bodies can be separately removed and serviced independently. Threaded NPT models are also available, described in other bulletins. Internal channels are 100% full-flow, having the same cross-sectional area as the equivalent pipe size. Standard pressure models are furnished with our quick-opening, hand-clamp closure for easy access. High pressure models have a stud-and-nut/bolted body cover closures.
Materials of construction include rugged cast iron bodies, covers, and iron valve plugs, and brass, carbon steel, stainless steel or monel baskets. Special valve plugs can also be furnished in bronze, stainless steel or other materials.
These duplex strainers have a built-in, tapered plug valve that directs flow through either side without shutting off the flow. A valve handle guard shields the side in use. The standard valve handle swings over the inlet port. Special reverse valve handles that swing over the outlet port can also be furnished. Drain plugs are provided in each of the valve and basket chambers. An adjustable locking flange holds the valve plug on its seat. A separate external gland is provided to allow easy access to valve stem packing without complete disassembly, even while in service.
Strainer baskets are fabricated from perforated metal. The smallest common perforation size is 1/64 inch in brass and 1/32 inch in stainless steel. Filter baskets are manufactured by using fine mesh wire cloth over supporting perforated metal. Interchangeable strainer, filter and double element baskets provide a flexible range of operating choices. The basked is held on its seat by a spring basket handle. Normal flow is through the interior of the basket which then contains the collected debris when the baked is lifted out for cleaning. Reverse flow is also possible if desired. Magnet inserts are available to help eliminate fine metallic ferrous particles.
All high pressure ("H") models with stud and nut closure are supplied with balancing valve assemblies to equalize pressure and ease valve turning. These should be specified on standard pressure models when used above the following pressures:3/4 inch through 1 1/2 inch inclusive - 100 PSIG; 2 inch through 3 inch - 80 PSIG; 4 inch through 8 inch - 15 PSIG
An optional lifting jack can be provided to lift the valve plug off its seat for ease in valve turning in rough service on sizes 1 through 4 inch. A lifting jack is standard on 5, 6 and 8 inch sizes.
