Construction
The standard guffer consists of an inner flexible part which is finished with a sealing
with a spring. The bearing can also be fitted with a second cutting edge (dust cap),
which protects the sealing lip from contamination. The outer part of the seal is made of a metal
reinforcing ring encased in an elastic sheath. The elastic sheath eliminates temperature
expansion and surface roughness of the bay.
Special versions of the guffer may have a stainless steel spring, metallic sheath, metallic
sleeve or hydrodynamic edge grooving. They may be double-sided or
without spring,
Overview of types
Standard bearings without dust cap type A (G)
Version A (G) is the standard type of bearing. Due to the absence of a dust cap,
which protects the sealing lip from dirt, type A is more suitable for applications
applications with a clean external environment. Alternative designations: BA, DR101 SealJet.
WA G NBR
Material: NBR
Operating temperature: -40 °C to +80 °C (max. 100 °C)
Circumferential velocity: ≤ 12 m/s
Operating pressure: ≤ 0.5 bar
For clean external environments. For applications without increased temperature or chemical resistance requirements.
VIA G FPM
Material: FPM (FKM)
Operating temperature: -30 °C to +170 °C (max. 200 °C)
Circumferential velocity: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
For clean external environments. For applications with higher
applications with higher temperature and chemical resistance requirements. Spring
is made of stainless steel.
SIA G SI
Material.
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
For clean external environments. For applications with higher
applications with higher temperature and chemical resistance requirements. Silicone
Silicone bearings are suitable for food processing.
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Standard bearings with dust cap type AS (GP)
The AS (GP) version is a standard type of bearing. Thanks to the dust cap, which
protects the sealing lip from contamination, the AS (GP) type is also suitable for contaminated
external environments that contain a high incidence of abrasive substances.
Alternative designation: BASL, DR102 SealJet.
WAS GP NBR
Material: NBR
Operating temperature: -40 °C to +80 °C (max. 100 °C)
Circumferential velocity: ≤ 12 m/s
Operating pressure: ≤ 0.5 bar
For dirty external environments. For applications without elevated temperature or chemical requirements
resistance.
VIAS GP FPM
Material: FPM (FKM)
Operating temperature: -30 °C to +170 °C (max. 200 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
For dirty external environments. For applications with higher
temperature and chemical resistance requirements. Spring
is made of stainless steel.
SIAS GP SI
Material.
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
For dirty external environments. For applications with higher
for applications with higher temperature and chemical resistance requirements. Silicone
Silicone bearings are suitable for food processing.
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Pressure bearings type SY
The SY version is suitable for sealing working environments with different
pressures up to 10 bar depending on the circumferential speed of the shaft.
Alternative designation: BABSL.
WASY
Material: NBR
Operating temperature: -40 °C to +100 °C
Peripheral speed: ≤ 10 m/s
Operating pressure: ≤ 10 bar
For applications without elevated temperature requirements
and chemical resistance. For applications with varying pressures up to 10 bar.
VIASY
Material: FPM (FKM)
Operating temperature: -30 °C to +200 °C
Peripheral speed: ≤ 10 m/s
Operating pressure: ≤ 10 bar
For applications with higher temperature and chemical resistance requirements. For applications with varying pressures up to 10 bar.
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Bearings with sleeve type B
Version B is a standard type of bearing, which is equipped with
metal housing. The metal outer sleeve guarantees a firm and precise
fit and increases the mounting resistance.
Alternative designation: B1, DR201 SealJet. B1SL, DR202 SealJet.
WB
Material: NBR
Operating temperature: -40 °C to +100 °C
Peripheral speed: ≤ 12 m/s
Operating pressure: ≤ 0.5 bar
For clean external environments. For temperature and chemical
applications. For chemical and chemical-chemical applications and for non-chemical and chemical-chemical applications.
increased resistance and higher fitting accuracy.
WBS
Material.
Operating temperature: -40 °C to +100 °C
Circumferential velocity: ≤ 12 m/s
Working pressure: ≤ 0.5 bar
For unclean external environments. For temperature and chemical
applications. The bearing has increased mounting resistance and higher fitting accuracy.
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Bearings with sleeve and reinforcement type C
Version C is a standard type of bearing, which is, however, equipped with
metal housing and reinforcement. The metal outer sleeve guarantees a solid
and precise fit. The metal liner gives the seal greater rigidity.
Alternative designation: B2 B2SL
WC
Material: NBR
Operating temperature: -40 °C to +100 °C
Peripheral speed: ≤ 12 m/s
Operating pressure: ≤ 0.5 bar
For clean external environments. For temperature and chemical
applications. The gauge has increased mounting resistance and higher fitting accuracy.
WCS
Material.
Operating temperature: -40 °C to +100 °C
Circumferential velocity: ≤ 12 m/s
Operating pressure: ≤ 0.5 bar
For unclean external environments. For temperature and chemical
applications. The bearing has increased mounting resistance and higher fitting accuracy.
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Bearings without spring type "O"
In the "O" version, the sealing lip is not fitted with a spring and the bearing therefore seals without
without the aid of spring pressure. Type "O" is designed for less demanding applications
with zero differential pressure of the sealing media.
WAO = BAOF NBR, RZV WBO = MZV, B1OF NBR, DR203 NBR SealJet.
WAO
Material: NBR
Operating temperature: -40 °C to +100 °C
Peripheral speed: ≤ 12 m/s
Operating pressure: ≤ 0 bar
For clean external environments. For less demanding applications
with zero differential pressure of sealed media.
WBO
Material: NBR
Operating temperature: -40 °C to +100 °C
Circumferential velocity: ≤ 12 m/s
Operating pressure: ≤ 0 bar
For clean external environments. For less demanding applications
with zero differential pressure of sealed media. Gufero
has increased assembly resistance and fitting accuracy.
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Bearings with hydrodynamic cutting edge ribbing
Hydrodynamic ribbing on the sealing surface of the blade promotes sealing effect
under difficult operating conditions. The inclined direction of the ribbing is adapted to
to the direction of shaft rotation and the ribbing helps return sealed
medium back into the sealed area.
We only offer the ribbed bearings in the dimensions specified by the manufacturer.
provided. The technical parameters of the hydrodynamic ribbed bushings are
are identical to the basic design without ribbing.
WAC G DL
Material.
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Circumferential velocity: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
WAH G DP
Material: SI
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
WAT GP DL
Material: SI
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
WAU GP DP
Material: SI
Operating temperature: -50 °C to +130 °C (max. 150 °C)
Peripheral speed: ≤ 35 m/s
Operating pressure: ≤ 0.5 bar
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Material properties
NBR (Nitrile Butadiene Rubber)
Resistance to: lubricants, mineral oils, HFA, HFB and HFC pressure fluids, water,
Glycol, kerosene, naphtha, aliphatic hydrocarbons, vegetable oils, fats.
Operating temperature -40 to +100 °C.
FPM (viton, fluorocaucuk)
Resistance to: mineral oils, highly additive gear oils, aliphatic
and aromatic hydrocarbons, acids, a wide range of chemicals, ozone, ageing,
weathering.
Operating temperature -30 to +200 °C.
SI (silicone)
Partial resistance to mineral oil, ozone, aging and weathering.
Maintains flexibility even at low temperatures. Suitable for the food industry.
Operating temperature -50 to +150 °C.
The choice of the appropriate rubber from which the bearing is made depends on:
- on the type of sealing medium and its temperature
- the circumferential speed of the shaft to be sealed
Table of temperature and chemical resistance of the offered rubbers
Maximum permissible circumferential speed for each type of rubber
Shaft and storage space requirements
Shaft material
A steel shaft and hardening of the surface at the point of contact is recommended. For the shaft
materials with poor thermal conductivity are not recommended.
Shaft hardness
To avoid excessive wear, the shaft surface must have a contact point of
with the sealing edge of the bearing at least 45 HRC at speeds v > 1 m/s.
The layer formed by hardening, cementing or nitriding shall have a thickness of
not less than 0,3 mm.
A shaft hardness of at least 60 HRC must be selected at speeds of v > 4 m/s, at
when sealing contaminated liquids or when sealing in dusty environments.
In corrosive environments or when thermal decomposition products are trapped
of the fluid to be sealed in the sealing joint, it is recommended that the shaft be chrome plated in a thickness of
0,02-0,1 mm and polished.
Shaft roughness
No machining marks (groove, etc.) must remain on the shaft. Surface roughness
of the shaft at a circumferential speed v < 4 m/s should be in the range Ra 0,4-0,8 µm.
The limit deviation of the shaft should be in the range h8 to h11. The shaft edge should be
be bevelled or rounded.
Storage space
Sealing of the liquid in the storage space is achieved by the overlap between the outer
diameter of the gauge and the hole. The limit deviation of the bore must be within the tolerance range of H8.
The surface roughness may be in the range Ra 1,6-6,3 µm. For ease of assembly
edge beveling is recommended. The minimum depth of the cylindrical part of the hole shall be at least
0,85 x the height of the bearing. The total depth of the hole (including the chamfered edge) should be
equal to the height of the bearing + 0,3 mm.
Tables for tolerance of alignment and shaft runout can be found in the attached files.
Installation
The installation rules are always given in the description of the specific type of bearing.