Industrial-Strength Hydraulic Seals for Diverse Industries

Hydroelectric Industry

These hydraulic seal products help keep hydraulic oil out of the water.

Turbine Styles

  • Kaplan
  • Francis
  • Bulb
  • Reversible Pump
  • Pelton Wheel

Kaplan Units

Their applications include blade seals (trunnion seals), wicket gates, turbine shafts, brakes, and servomotors.

Turbine Shaft Seals

We offer a range of braided packings with the common styles loaded with either Teflon or graphite. Both of them are supplied with a built-in breakout lube for initial start-up. Otherwise, we offer a spring energized bearing seal.

Adjustable Kaplan Blades

Known in the industry as Kaplan blade seals or trunnion seals, these products come in different designs depending on the available seal housing depth.

  • Back-to-Back V-Pack
    This style of packing is produced completely from rubber and molded to size and height. The packing set offers double redundancy in both directions using a bidirectional center gland ring. When the packing is supplied in split form, the intermediate rings are cut at a standard 45 degrees, and the center gland ring is cut with a diamond cut to reduce leakage path. The all-rubber design is used to avoid possible shrinkage when using standard fabric and rubber rings.
  • Floating Back-to-Back V-Pack
    This floating style does not require an initial compression on the seals to operate. It also offers the double redundancy and bidirectional ring. For OEM equipment, we supply the endless seal sets. On the other hand, for in-field installations, we supply a split seal design that is joined in the field, thus making it an endless seal set. The split set rings are supplied with a diamond cut for easy and proper alignment.
  • Floating U-Cup
    This style of seal is used for applications with a shallow packing box when you can only put one seal in each direction.

Bulb Units

The three styles of blade seals (trunnion seals) used on a Kaplan unit are also used on bulb units.

Wicket Gates

Can supply floating U-cups, floating V packing in standard material or from all rubber due to low pressure.

Wicket gates are used on Kaplan, Francis, bulb, and reversible units. They are low-pressure sealing applications recommended by our professionals.


We have supplied several seal designs and materials for this particular application.
Our team recommends using a floating V-pack, a standard V-packing, or a floating U-cup.


  • Servomotors
  • Wicket Gates
  • Gate Seals
  • Adjustable Blades
  • Brakes
  • Gates
  • Turbine-Hydro and Turbine-Francis Turbine
  • Transformers

Recommended Seals

  • V-Packings
  • Floating V-Packings
  • U-Cups
  • C-Packings
  • Back-to-Back V-Packings
  • BladeSeal Dual
  • BladeSeal Twin
  • J Seals - Music Note
  • Shaft Braided Packings
  • Gasket Materials

Wood Industry

The hydraulic products we manufacture are for the plywood, oriented strand board (OSB), particleboard, medium-density fibreboard (MDF), pulp, laminating, and melamine businesses. They generally manufacture their products on multi-opening presses operated by hydraulic oil.
The most common hydraulic presses found in these industries are manufactured by the following companies: Washington Iron, Dieffenbacher, Fjellman, Motala, Williams, White & Company, Siempelkamp, Globe, and Superior. Specialty Sealing Technologies has been supplying the products for the main rams, jack rams, loaders, and unloaders.

Applications and Products

Main Rams

  • Floating V-Packs
  • V-Packings
  • Robust Floating V-Packs
  • Floating U-Cups
  • Rubber Double Wipers

Jack Rams

  • Floating V-Packs
  • V-Packings
  • Robust Floating V-Packs
  • All Rubber Double Wipers

Loaders and Unloaders

  • Floating V-Packs
  • V-Packings
  • Floating U-Cups
  • L-Type Wipers

Extrusion and Forging Industry

These industries require the most durable and robust design packings in the market today. We offer a heavy-duty style packing that is widely used in these industries. The sealing rings are designed and manufactured to accommodate higher pressures, heavier workloads, and deeper stuffing boxes. The packing will work in standard hydraulic fluids, water, or an oil-water mix.

Extrusion Applications

  • Main Rams
  • Pull Backs
  • Containers
  • Butt Shears
  • Die Slides

Forging Applications

  • Main Rams
  • Pull Backs
  • Containers

Compression Moldings

Robust V-Pack and Robust Floating V-Pack

This packing is manufactured primarily for heavy and harsh sealing applications. The sets are constructed from molded fabric and rubber consisting of a series of intermediate (V-rings), header (male) and gland ring (female). All the rings are taller in height than the standard V-pack, which offers greater strength for harsh conditions. The header ring is normally supplied from molded fabric to offer greater compression and strength to the set.

Robust V-Pack

This packing is manufactured for applications when a heavier and taller set of rings are needed. All rings are molded with the purpose of use in heavy applications where they will encounter high pressure and abnormal side loads. The set is to be used when filling deep stuffing boxes.

Robust Floating V-Pack

This packing is manufactured for applications when a heavier and taller set of rings are needed. All rings are molded with the purpose of use in heavy applications wherein they will encounter high pressure and abnormal side loads. The sets are to be used when filling deep stuffing boxes. Floating V-pack is manufactured to float inside the seal housing. All rings are taller in construction and normally a larger cross section.
The floating V-pack is intended to be maintenance-free once installed. The packing is not compressed with a built-in interface, which allows the (male) manufactured will seal under low pressure up to 8000 PSI.

Hydraulic Cylinder Repair

We provide seals with nonstandard cross sections in small quantities, without mold or set-up charges. Simply let us know the specifications, and we’ll fabricate the hydraulic seals depending on your industrial application.

A List of Seals We Design and Manufacture

  • U-Cups
  • Floating U-Cups
  • V-Packings
  • Floating V-Packings
  • Robust Style V-Packings
  • Robust Floating V-Packings
  • Oil-Bearing Seals for
    Rotating Applications