MECO EP-Type-1

Where axial or linear space is available, the MECO EP Type-1 seal model is the answer for sealing wet abrasive slurries encountered in pulpers, agitators, cylindrical blenders, paddle mixers, holding vessels, flocculators, mixing conveyors and similar rotating equipment. When linear space is limited, MECO’s EA Type-1 model can offer similar performance with manual adjustment. The EP Type-1 model is used in process industries such as pulp & paper, home building products, sewage and water treatment, biomass and ethanol production, along with other processes handling water slurries. They are frequently used on bottom-entry pulpers containing clean wood fiber, recycled office paper and old corrugated containers (OCC). They withstand the abuse of shock loading, high shaft runout and abrasives often associated with pulpers. The entire assembly is fully-split and serviceable onsite.

The MECO EP Type-1 seal model is a precision machined, fully-split seal akin to a stuffing box and gland follower. The elastomer drive consists of two stainless steel rotating seal faces surrounding a drive elastomer. The drive elastomer and two rotating seal faces interlock with the shaft, forming a watertight seal at the shaft. The result places the rotating seal faces at right angles to the shaft and in full contact with the low-friction stationary seal faces. The rotating parts are fitted around the shaft prior to installing the seal housing.

The nose or pilot of the gland follower provides the carrier for attaching the outboard (secondary) stationary seal face. A plate attached to the bottom of the seal housing (a.k.a. stuffing box) provides the inboard (primary) stationary seal face. These precision-machined stationary seal faces (stators) are inherently malleable to mate against lapped and polished rotating seal face surfaces. The seal cavity is flushed with water to remove any debris and quench or cool the seal faces.

The MECO EP Type-1 seal model uses a continual water flush to remove any process debris within the seal cavity, as a quench to reduce heat generated by the seal and as a diagnostic tool. The flush provides insight into the seal setup prior to startup and the overall performance during its lifecycle. By reviewing the clarity of the flush water, the change in water temperature from inlet to outlet, and the ability to hold water within the seal cavity, maintenance becomes predictable and the calibration is confirmed.

External springs are attached to the back of the gland follower to close the seal faces and provide seal face alignment capabilities. As the sacrificial stationary seal face material wears, the springs will gradually expand and the flush water will expel process debris. After the springs have expanded measurably, an opportunity should be scheduled in the next 1-2 weeks to reset the springs to maximize seal life. Once the gland follower flange is in contact with the seal housing, a rebuild is needed. The seal may be rebuilt on-site or returned to MECO for factory refurbishing.

The MECO EP Type-1 seal model is designed and built to order. Assemblies are fully split. Common shaft diameters range from 4” (100mm) to 16.5” (420mm) and include all sizes in between and many outside the range. Dimensions will vary according to each application, but typical dimensions are shown in the illustration below. Any extra axial space is helpful for the installer and maximizes spring performance. The seals are designed fully-split to fit most mounting arrangements. Seals can be built either to S.A.E or metric dimensions. Designer-friendly, they are equally appropriate as retrofits or for new equipment.

Viton® is a registered trademark of E.I. Dupont de Nemours & Company.

The MECO EP Type-1 seal’s rugged components are designed for long life. The standard assembly uses stainless steel rotating seal faces. The housings and gland follower are typically machined from 304 or 316 stainless steel.

Common high-performance bearing-grade stationary seal face options are as follows: MECO 3000, a slick polymer-filled PTFE; MECO 3120, a malleable ceramic-filled ptfe; MECO 4000, a hard, carbon fiber, graphite & PTFE-filled PEEK. The common elastomer is EPDM with white silicone, Viton® and Nitrile rubber are viable alternatives. These materials have an FDA-compliant option.

Since Woodex MECO manufactures many custom MECO shaft seals, we have the capability to fabricate from many materials.

Specifications

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