Replaces stuffing boxes and face seals. The Hydraulic Seal TS is the result of a direct application used in the industrial field.
Tested under the worst conditions (acids etc.). It may be considered the evolution of oil systems used in ships:
- Bilge permanently dry.
- Resolve the problem of “face& water” seals.
- Safe and durable.
- No adjustment required.
- Resistance to sandy waters.
- Resistant to sea incrustation (permanence in water).
- Ecologically approved.
- 5 year guarantee.
- Recommended by professional shipyards.

U.S.A Patent n° 5,795,198
EUROPEAN Patent n° 0770017
RINA Approval mac/217/94

VERITAS Approval 09714/AO/BV


BUILT IN OIL PUMP. The Hydraulic Seal TS is a bearing with oil seals inside. The bearing has a special interior profile which creates an oil circulation with the rotation of the propeller shaft. This patented bearing is a real pump, its reliability is absolute: no gears or moving parts. The circulation allows the bearing and the oil seals to work on an oil film: no friction and good durability.

PROTECTING CHAMBER. On the sea side, the Hydraulic Seal TS has a patented grease chamber. Its function is to protect the oil seals from sand and incrustations, and to prevent any oil emulsion. The water pressure avoids the escape of the grease from the Hydraulic Seal TS.

A.V.S. SYSTEM (Anti Vibration System). The Hydraulic Seal TS has an interior mechanical articulation that always ensures a flexible connection to the stern tube. The Hydraulic Seal TS does not depend on the elasticity of thin and delicate rubber sleeves (face seals, water seals).

ABSOLUTE SAFETY: resolve the problems and dangers of “face” & “water” seals.
Everybody knows the risks of a stuffing-box; to over tight may burn it, whilst excessive play may inundate the bilge… To simplify the life of the pleasure owners (less adjustments), the market offers “face” and “water” seals. These systems are efficient only if their working conditions are optimal, in other situations they can be very dangerous (sinking). Naval registers (as RINA and VERITAS) forbid their use in working boats (superior approvals). The causes of sinking are numerous: they burn completely if there is an obstruction of the water lubrication (plastic and rubber components).
If there is an incidental fire on board they burn completely (plastic and rubber components).
Face seals cannot support front and back movements of the shaft (only few millimetres): a trunk hits the propeller and moves the shaft, accidental disconnection of the shaft (vibrations loosing the bolts), a rope rolled on the shaft and forcing on the strut and the shaft…
Face seals are connected to the stern tube by a very delicate rubber sleeve which may be destroyed by the interior incrustations attached on the propeller shaft. Propeller shaft vibrations may cause disconnection of the face seal form the shaft (frequent incident).
Face seals don’t support sand and incrustations (a long permanence in the water): faces furrow and so water infiltrates. Face seals do not support misalignment of the propeller shaft (incidents, bearings worn-out, a shaft twisted…): these can become dangerous.
The seal ring of a “water seal” is rapidly destroyed by propeller shaft incrustations and the life of the water lubricated bearing is short (sand and incrustations). The incrustations stick to the “water seal” bearing and propeller shaft: when the shaft starts its rotation the connecting rubber sleeve breaks.

The Hydraulic Seal TS can eliminate each kind of incident concerning the propeller shaft
- Front and back movements, vibrations, misalignments)
- Sand and incrustations (protecting grease chamber),
- No dependency on delicate rubber sleeves (a.v.s. system),
- No dependency on water lubrication (obstructions etc),
- Operates without oil and grease (incident or absence of maintenance).
The Hydraulic Seal TS, VERITAS and RINA approved, is used on boats requiring superior approvals: working boats, stem boats, military boats.

NO ADJUSTEMENTS, NO RISKS. The Hydraulic Seal TS does not require adjustments, only a periodical check of the oil level and grease. In case of pleasure boat it is enough to check annually. Its safety is always present, even if there is no oil and grease (incident, absence of maintenance...).
NO FRICTION: best performance.
Navigating with a stuffing-box is like driving with the hand-brake on: excessive friction on the shaft. The oil film created by the Hydraulic Seal TS stops any friction: better performance and less fuel consumption. When sailing and letting the shaft run freely, the drag will be less than a propeller held by a stuffing-box.

"Riva Ferrari "
800 cv – 4000 rpm – equipped with Hydraulic Seals TS.
Diagram of the moment of resistance (kmg) of the Hydraulic Seal TS based on the tests of “Riva-Ferrari” shaft (1”3/4 in diameter). Tested when cold: dotted line. Tested at functioning temperature: continuous line.

100% WATERTIGHT. The temperature originated from the high friction of the stuffing-box, and the temperature of the engine, create a real nebulization of the water penetrations. Even if the accumulated water appears of little quantity, the salt invades all the bilge (salt nebulization).
This phenomenon is amplified by the face seals (friction of the faces). The life span of marine engine is reduced by the creation of this corrosive environment Stagnant sea water generates putrefaction, often all the interior of the boat is impregnated by a typical foul smell (common in many boats).
The Hydraulic Seal TS is 100% watertight. Consequently it preserves the reliability and the value of the engines. Further to this it also prevents foul smells and moulds.

ECOLOGICALLY SOUND. The Hydraulic Seal TS being 100% watertight, respects automatically the environment laws prohibiting the evacuation into the sea of the bilge waters. The Hydraulic Seal TS can work with ecological oil and grease, so it has no problems with the restrictive pollution laws of certain countries.



DURABLE 5 YEAR GUARANTEE. The Hydraulic Seal TS is made in bronze, a noble metal practically endless.
The only component subject to wear and tear are the oil seals. They work on a oil film (no friction) and are protected by the grease chamber. Their longevity is measured in ‘thousands’ of hours. When they are worn you observe a little pool of oil coming from the Hydraulic Seal TS which is collected in a small reservoir. You can continue to navigate without any problems.
After changing the oil seals, the Hydraulic Seal TS becomes as new.
EASY TO INSTALL. The Hydraulic Seal TS may be installed on any existing stern tube without any modification. For new boats the Hydraulic Seal TS may be supplied complete with stern tube.