PTFE Cup Seals for Pneumatic & Low-Pressure Hydraulic Applications

PTFE cup seals are single-piece PTFE lip seals that rely on PTFE's memory behaviour — no springs or energizers — to seal piston and rod grooves in pneumatic and low-pressure hydraulic systems.

The Lycotek range covers six models — L-cup (MLP, MLR), U-cup (MUP, MUR), guided block (MGP, MGR) — from -40 °C to +220 °C, up to 15 m/s (reciprocating) / 1 m/s (rotary), below 20 bar, for compressors, pneumatic valves, food processing and paint application.

Key features

Conventional elastomer-only seals lose lip contact as temperature rises, swell in aggressive media, and their rubbery friction causes stick-slip and high break-away force. PTFE cup seals avoid all of this: they are single-piece seals that rely on PTFE's memory behaviour to stay in contact — no energizers, no springs.

1. Self-energizing PTFE memory design — no springs, no O-rings

The lip keeps sealing contact through PTFE's inherent memory behaviour, not through elastomer energizers or metal springs. This keeps the design single-piece and compact, with the seal force stable over the full -40 °C to +220 °C range.

2.Stick-slip free with consistently low friction

Friction stays extremely low and constant across a wide temperature range, and no stick-slip occurs even at low sliding speeds. Break-away force remains minimal even after long standstill — ideal for valves, solenoid valves and metering equipment.

3.Excellent dry-running capability

Runs reliably without lubrication, which suits compressors, vacuum pumps and pneumatic cylinders where oil-free operation or intermittent lubrication is common.

4.Chemical and heat resistance

High resistance to chemicals and heat, with no volume change from expansion or contraction — sealing geometry stays true across the full -40 °C to +220 °C range and in aggressive media found in food-processing and paint-application equipment.

5.Compact, economical single-piece design

One-piece moulding keeps the seal compact and cost-effective, and special sizes are available on request. The range covers piston and rod installation in L-cup, U-cup and guided-block profiles.

Product Range

All six models share the same pressure, speed and temperature limits — what sets them apart is profile, mounting direction and rotary-service rating. Use the table below to match each model to your application type.

Rod Seal	Bore Seal	Application Type *	Product Type	Operating Limits	Features
MUR U-cup	MUP U-cup	Reciprocating-A Rotary-C Static-C	Piston seal Rod seal Rotary shaft seal	Pressure < 20 bar Reciprocating speed < 15 m/s Rotary speed 1 m/s Temperature -40 °C to +220 °C	· Suitable for open and half-open grooves · Tolerant of large radial runout · High-temperature deformation compensation
MLR L-cup	MLP L-cup	Reciprocating-A Rotary-B Static-C	Piston seal Rod seal Rotary shaft seal Wiper	Pressure < 20 bar Reciprocating speed < 15 m/s Rotary speed 1 m/s Temperature -40 °C to +220 °C	· Compact design · Low cost
MGR Guided block	MGP Guided block	Reciprocating-A Rotary-B Static-C	Piston seal Rod seal Rotary shaft seal Wiper	Pressure < 20 bar Reciprocating speed < 15 m/s Rotary speed 1 m/s Temperature -40 °C to +220 °C	· Compact design · Integrated guide and support function