Seals and rings specifications

General

Soetanto^Ò H-rings solve your sealing problems in the hydraulics and pneumatics fields even better.
With Soetanto^Ò H-rings, you have a reliable and proven sealing element at your disposal. The technical superiority provides the following.

Advantages

Universally applicable for hydraulics and pneumatics
Low friction, even when running dry
No "stick-slip"motions
Wear resistant
Space saving designs
Simple installation
Very good chemical resistance
Temperature resistant up to 200^oC (390^oF)
Pressure resistant to over 2000 bar

Function

The Soetanto^Ò H-ring consists of a clever combination of a ring with a rectangular section made of special PTFE (polytetrafiuorethylene) and an O-ring made of synthetic rubber. The rings are inserted into a groove with a rectangular section.
The wear resistant PTFE-ring provides the dynamic sealing. The elastic O-ring serves as static seal and gives the PTFE-ring a uniform pre-tensioning. The pressure of the medium assists the sealing effect. Soetanto^Ò H-rings are double-acting.

Application

Dynamic seals are used for hydraulic liquids, steam, gases, air and are applied on pistons, rods and slowly turning shafts in hydraulic or pneumatic equipment as well as in general industring applications.

Fields of Application

Vacuum and pressure up to and over 2000 bar Temperatures from -60ºC up to +200ºC
(-76º up to +390ºF) depending on pressure, lubrication and cooling Sliding speed, oscillating, up to 12 m/sec.
Speed, rotating, depending on operating conditions Ask for our rotation seals.
Chemical resistance is limited by the O-ring (VMQ, FPM, etc.)

Materials

The rectangular sealing ring is made of specially filled (modified) PTFE.The filling materials used, such as glass, carbongraphite, bronce, MoS² or combinations of various components improve the wear resistance, pressure resistance, heat conductivity and thermal expansion of PTFE. The chemical resistance is excellent. The O-ring material is selected according to the operating conditions fluid and temperature (NBR, FPM, VMQ etc.).

The standard O-ring supplied is made of NBR. It is resistant against mineral greases, oils and fuels, glycols, air, gases, acid or alkaline aquaeous solutions (please ask for our chemical resistance list).

Chemical resistance of the O-ring materials

Material	Recommendation	Temp. range
NBR Nitrile rubber	Standard quality for water, hot water, mineral oils and greases, aquaeous acids and leaches, diesel - and heating oil, fuels	-20º up to +100ºC (-5º up to 210ºF)
FPM Viton	Excellent chemical resistance, even at high temperatures ozone and weather resistant	-25º up to+250ºC (-10ºup to 480ºF)
VMQ Silicon	Hot air, oxygen, dry gases (utilized as a foodstuff seal)	-50º up to+220ºC (-60º up to 430ºF)

Other qualities on request.

Guide

The Soetanto^Ò H-ring does not serve as guide. If the parts to be sealed are in direct sliding contact, we recommend the standard fit H8/f8.

If a guide ring is foreseen, then the metallic parts can have the following average radial clearance:
   up to   40 bar    0,6 mm
   up to 160 bar    0,4 mm
   up to 400 bar    0,3 mm
   up to 500 bar    0,2 mm

These indicative values are applicable up to temperatures of 80ºC (175ºF) For standard dimensions of the guide rings, refer to page 5.

Safety

Soetanto^Ò H-rings are double-acting. Normally one ring is sufficient for sealing a double-acting piston.
In case of extreme conditions, 2 rings can be applied (pressure shocks, high frequencies, safety).

Surface quality

For the machining of the sliding surfaces on cylinders and rods/shafts, we recommend
1 - 1,5 µ Ra (N7) for cast iron; for steel 0,5 - 1 µ Ra (N6).

Light alloy cylinders become very wear resistant by hard anodizing. Hard chrome plated piston rods assure a good seal and a long service life. Subsequent fine grinding or external honing increases the sealing effect.

Fitting dimensions

Groove dimensions and order No. for piston - and rod/shaft seals can be seen on the list of standard dimensions. Intermediate sizes or special rings for already existing grooves can be manufactured by us at short notice.