PTFE Seals

PTFE Seal

The PTFE Seal consist of a PTFE sealing element and a rubber O-ring functions as elastic energizer. The required sealing effect is achieved by radial pressure, produced by the preloaded element and system pressure.

Outstanding features of PTFE Seal are:
- wear resistance can be improved by proprietary fillers
- very good in sealing most of chemicals
- high extrusion resistance
- good thermal conductivity (ranging from -450 deg F to +600 deg F)
- easy fitting

Application:

- low break-out and low friction hydraulic cylinder
- low friction and no stick-slip pneumatic cyclinder
- Plunger
- Cyclinders in corrosive environment
- Low friction cyclinders in high-temperature application
- Cylinders for machine tool and construction equipment
- Cylinders for press/ extrusion/ injection molding
equipment
- Cylinders for precise control application

Code	Material	Color	Temperature	Water Resistance	Main Application
1	Virgin PTFE	White	-200 to 290°C	1	Static, vacuum and cryogenics
2	Carbon filled PTFE	Black	-200 to 290°C	8	Medium=duty hydraulic, pneumatic, water/oil emulsion, seawater
3	Bronze filled PTFE	Green	-200 to 290°C	3	Hydraulic, heavy mechanical stress
4	UHM WPE	Transparent	-200 to 80°C	10	Excellent wear resistant for low temperature application
5	Carbon Fibre PTFE	Black	-260 to 310°C	8	Very good wear properties in water

PTFE Seal is required to achieve better performance in Cylinders

The hydraulic and pneumatic cylinders act as not only actuator but also precise positioner to meet increasing demands derived from more complex process equipment. Elastomer energized PTFE seals can provide much lower friction without any stick-slip effect to guarantee smooth running even for intermittent operation or long-stroke application. They perform reliable sealing function even under high service pressures and/or high surface speed. PTFE with inherent low friction and wear resistant property can effectively improve service life of the seal on reciprocating applications and help reduce maintenance cost.
Moreover, it also preferred in certain unfavorable applications such as construction equipment, chemical process, off-shore, galvanizing and color coating line and coal-fired power plant where dusty, high-temperature, aggressive media, or intermittent movement are quite common in sealing environment.
FDA approved PTFE Seals are widely adopted by foodstuff, pharm, and semi-conductor process equipment. Rotary PTFE Seals are also available.

Design

The PTFE seal sets consist of a PTFE sealing element and a rubber O-ring functions as elastic energizer. The required sealing effect is achieved by radial pressure, produced by the preloaded element and system pressure, on the lip against mating surface. Various seal profiles can fit most of single and double acting cylinders. Some compact profiles have been well developed to fit AS 568A standard O-ring grooves for one or two back-up rings.

Outstanding features of PTFE Seals are:

1. Excellent gliding characteristics due to low friction
2. Wear resistance can be improved by proprietary fillers
3. Very good in sealing most of chemicals
4. High extrusion resistance
5. Good thermal conductivity
6. Full range pf sizes available
7. Easy fitting

Applications

1. Low break-out and low friction hydraulic cylinder
2. Low friction and no stick-slip pneumatic cylinder
3. Plunger
4. Cylinders in corrosive environment
5. Low friction cylinders in high-temperature application
6. Cylinders for machine tool and construction equipment
7. Cylinders for Press/Extrusion/Injection molding equipment
8. Cylinders for precise control application

Type

PTFE Wipers

PTFE wipers are mainly used where wipers of other materials would fail because of the particular operating conditions involved. Their function lies in preventing foreign particles or fluids from preventing into the sealing area, thereby protecting the seals, guides and bearings behind the wipers from wear and damage.
Sealing pressure on PTFE wiper lip is usually energized by an elastic O-ring. The standard material combination is bronze filled PTFE and NBR. This is mainly utilized in hydraulic and pneumatic application.

PTFE Seal Sets for O-ring fitting areas

Seal sets of type RO and PO can be used in hydraulic applications in place of dynamically stressed O-rings. Existing grooves can be used as fitting area if they conform to the US standard AS 568A.
These seal sets enable the dynamic behavior to be improved, as a result of which higher gliding speeds, smoother running properties and higher wear resistance are attained. PTFE Glide Seal sets can also be used in O-ring fitting areas designed for one or two back-up rings.
Care must be taken in the design to ensure that the groove width L is selected according to the number of back-up rings. The standard material combination is modified PTFE and NBR (O-ring).

Material combination of PTFE Glide Seals

Code	PTFE Compound	O-Ring	Application
11	Virgin PTFE	NBR	Suitable for foodstuffs and pharmaceutical process
12	Virgin PTFE	FPM	Same as above but service temperature up to 200°C
21	Carbon filled PTFE	NBR	General application with excellent chemical resistance
22	Carbon filled PTFE	FPM	Same as above but service temperature up to 200°C
31	Bronze filled PTFE	NBR	Hydraulic, high pressure, wear resistance, good thermal conductivity
32	Bronze filled PTFE	FPM	Same as above but service temperature up to 200°C

For more informations, please contact our customer service.