MECO EA-Type-2

The MECO EA Type-2 seal model is used on large solvent extractors, pressurized conveyors, holding tanks or similar rotating equipment. It’s also used on some blenders, dryers & sigma mixers. Common industries that use the seal are plastics, oilseed processors, chemicals, carbon anodes, metals, pharmaceuticals and food processors. They are available fully-split and are frequently used on rotating shafts where an inert gas barrier in the seal chamber is beneficial.

The seal is appropriate for vacuum service and steady-state applications with infrequent thermal expansion or pressure changes. The seal is adjustable without having to empty the process vessel. For applications with frequent thermal cycles, pressure cycles and/or aggressive chemicals, the MECO Model EP Type 3 seal can be a better match.

The EA Type-2 seal model replaces standard stuffing boxes & packing glands. The seal incorporates separate inboard and outboard housings, each containing either an integral or replaceable stationary seal face. Between the stators is a rotating seal face assembly, consisting of two replaceable rotors and a drive elastomer. The stators are drawn together to compress the two seal rotors against a central driving elastomer. The drive elastomer and rotors interlock to the shaft, forming an airtight seal. The low-friction rotating seal faces are at right angles to the shaft and in full contact with the stationary seal faces.

An adjusting gasket permits the distance between the two stator housings to be varied, while containing a barrier gas within the seal. The EA Type-2 seal cavity is charged with low-pressure air or an inert gas, which provides pneumatic seal face loading. This is a simple and effective way to check installation integrity and monitor seal performance. EA Type-2 seals are manufactured to exacting standards, which ensures parallelism and flatness to maximize product containment and minimize barrier gas consumption.

The MECO EA Type-2 seal model uses the barrier gas to pneumatically load the rotating seal faces and as a diagnostic tool. A pressure regulator is included with the seal to set inlet seal cavity pressure. A pressure gauge is attached to the inboard stator to monitor seal cavity pressure. Assembly bolts or studs link the two stators. By controlling the distance between the stators, seal face loading is generated. Over time, the gas pressure will gradually reduce as the sacrificial rotors wear. Using the assembly bolts to re-position the outboard stator resets the rotating seal faces and increases the pressure in the seal cavity. Once the seal cavity pressure can no longer be maintained, the rotors and driving elastomer may be replaced with fully-split components.

The MECO EA Type-2 seal model is custom-designed and built to order. Typical assemblies are fully-split. Shaft diameters range from 1″ (25mm) to 20″ (500mm) and include all sizes in between. Dimensions will vary according to each application, but typical dimensions are shown in the illustration below. Having extra axial space is always helpful for the installer. EA Type-2 seals are readily designed to fit most mounting arrangements specified by equipment OEMs, and are designer-friendly, to interface with customized, in-house process equipment requirements. Seals can be built either to S.A.E or metric dimensions.

The MECO EA Type-2 seal’s rugged components are designed for long life. Two different housing/stator combinations are available. The EA Type-2A, consists of aluminum housings with replaceable 300 series stainless steel stators attached. The EA Type-2S uses integral 300 series stainless steel stators. Other stainless or high-nickel alloys are also available.

Two common rotor material options are MECO 3000, a high performance, bearing grade, polymer filled PTFE with FDA approval, or glass-filled PTFE, but many others are available. The different elastomer options available are Silicone, Viton®, EPDM and Nitrile and all have an FDA compliant option.

Since Woodex Meco manufactures many custom MECO shaft seals, we have the capability to fabricate from a wide variety of materials.

Specifications

Results may vary with operating conditions – please call for discussion.