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7500 Series Rotary Shaft Seals

Our 7500 Series CinchSeals are designed for zero maintenance due to the unique self adjusting design. These are ideal for screw conveyors, bucket elevators, and similar bulk solid applications.

The 7500 Series consumes 30% less power than packing seals and will not undercut shafts. Fully assembled and possessing a rugged modular design, our 7500 Series will not leak to foul bearings or contaminate processing areas.

How the 7500 Series – Rotary Shaft Seal Works

The 7500 Series is offered in two different versions: the 7550 which is for most powder applications, and the 7520 version for slurries or very abrasive applications. The key component of the 7500 seal is the solid elastomer, which is made from FDA approved silicone and can handle temperatures up to 400F degrees. The elastomer is molded slightly smaller than the shaft size so that an interference fit is achieved. It is this tight fit that seals the shaft, which stops material from migrating past, and drives the two rotating faces called “rotor cups”. The rotating rotor cups compressed against the two stationary stator plates is what creates the primary seal that stops product leakage. The seals are also air purged at 5 to7 PSI above any pressure in the vessel to assist in maintaining a positive seal.

The fact that the 7500 seal turns with the shaft is a major benefit for customers. Because rope packing is stationary and the shaft is turning through it, it can score and damages the shaft; which can lead to a big expense when you have to replace the shaft. With CinchSeal, the internal seal elements turn with the shaft and shaft damage is eliminated.

In the 7550 series the rotor cups are made from a special mineral filled PTFE blend, and are the wearable part of the seal. On the 7520 model the rotor cups are made out of aluminum that we hard coat with a special process that give them a hardness of a 62 on the Rockwell scale. (The same hardness as Tungsten Carbide) The hard coated aluminum rotor cups run against inner and outer PTFE stators, which are now the wearable part of the seal and will be replaced when worn.

When buying a repair kit for the 7550 model it would consist of a new solid elastomer and new PTFE rotor cups. If you have a 7520 model a repair kit consists of a new elastomer and two new PTFE stator plates. (See exploded views below) All these pieces compress into the seal as you tighten down the cover plate with the 4 screws and the optimum seal face load is established.

The newly rebuilt seal is bolted up to the machine where it will run for 1,000’s of hours providing leak free service before a repair kit will be needed.

7520 Assembly 7550 Assembly
Materials of construction: Anodized aluminum housing with o-ring at inboard and outboard plate. PTFE inboard and outboard stators. Aluminum hard coat rotor cups, elastomer and springs. Materials of construction: Anodized aluminum housing with o-ring at inboard. Anodized aluminum inboard stator and outboard plate. PTFE rotor cups, elastomer and springs.

Standard Features

  • Designed for C.E.M.A. screw conveyor and bulk handling equipment, the 7500 series is a self-adjusting seal.
  • Temperature ranges -50F/44.55C to 400F/204C
  • Bolting pattern will accommodate flange mounted bearings
  • Materials available anodized aluminum
  • Designed to handle linear shaft growth, and axial runout
  • Purge with air, 5 to 8 psig above vessel pressure, or silicone grease

Available Accessories

Self Adjustment and Aligning

The CinchSeal module readily accommodates a reasonable amount of shaft vibration, misalignment or wobble. The rotor cup "floats" against the face of the stator plate so any lateral shaft movement produces nothing more than a slight orbital eccentricity. View Our Installation Guides

7500 Series – Rotary Shaft Seal Dimensional Information

A B C D (min.) D (max.) E (min.) E (max.) F
1,5 0,625 5,375 3,3 4,357 4,709 6,162 1,75
2,0 0,750 6,50 4,0 5,386 5,657 7,618 1,75
2,437 0,750 7,375 4,5 6,260 6,364 8,856 1,75
3,0 0,880 7,875 5,5 6,677 7,778 9,443 1,75
3,437 0,880 9,25 6,76 8,052 9,560 11,387 1,75

View Our Warranty

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